Saturday 30 January 2021

Chapter 8 Human Health and Disease








DEFINITION OF HEALTH: According to Greek and Indian Ayurveda System. health was considered as a healthy state of body and mind, which is

free from diseases and infections.

But according to W.H.O.“Health is a state of complete physical, mental, social and behavioural wellbeing’.


DISEASE: Disease is any condition which impaires normal functioning of body or some part of the body, associated with specific symptoms.


Symptoms: Symptoms are evidence of presence of disease. However symptoms do not give any exact cause of disease


DISEASE AGENTS: Any substance or agent which causes disease by its excess or deficiency or presence or absence is called disease agent.

Disease agents can be biological [eg Bacteria, virus, fungi, protozoans and

worms] or chemical, physical or mechanical.


Etiology: Study of causes of disease is called etiology.


CLASSIFICATION OF DISEASES: On the basis of occurrence diseases are of two types:

1. Congenital or Inborn

2. Acquired


Congenital diseases: Congenital diseases can be defined as structural or functional disorders that are present by birth. These conditions develop prenatally. Congenital diseases can be caused by gene mutations or

chromosomal mutations.


Acquired diseases: These diseases develop after birth and may be caused by pathogens, deficiency of nutrients. allergies or organ malfunctions.


Acquired diseases may be communicable or non communicable Communicable or infectious diseases are transmitted from one

person to other and are caused by pathogens like Viruses, Bacteria, Fungi,Protozoa and Worms etc.


Non communicable or non infectious diseases are not transmitted from one person to the other. These diseases may be organ degenerative diseases, diseases due to hypo or hyper secretion of hormones, allergies,

deficiency diseases or cancer.


Transmission of diseases: Communicable diseases are transmitted from infected persons to healthy persons either directly or through intermediate agents.


Direct transmission takes place through contact with infected persons,droplet infection or through placenta.Indirect transmission takes place through arthropod vectors, airborne methods or human carriers etc.Arthropod vectors transmit disease through many ways:


Housefly carries causative organisms of cholera, typhoid, dysentery and

tuberculosis on the legs and mouth parts from faeces and sputum.Ants, Cockroaches and House crickets also carry germs to food articles.

Mosquitoes carry diseases like Filariasis, Malaria, Chickenguniya, Yellow fever etc.Epidemiology is a branch of medicine which deals with epidemic disease.


Balanced diet, personal hygiene and regular exercise are very important to maintain good health. Yoga has been practised since hundreds of years in India to achieve physical and mental health.For achieving good health awareness about diseases, vaccination against diseases, maintaining personal hygiene and proper disposal of waste is






1. Which of the following factors affect human health?

(a) Infections

(b) Lifestyle

(c) Mutations

(d) All of these


2. Which of the following diseases is non communicable?

(a) Cancer

(b) Diphtheria

(c) Influenza

(d) Malaria


3. Which of the following is a communicable disease?

(a) Allergy

(b) Cholera

(c) Depression

(d) Diabetes


4. Which of the following disease can be avoided by washing hands frequently?

(a) Amoebiasis

(b) Kala azar

(c) Cancer

(d) Malaria


5. The organisms which cause disease in plants and animals are called............

(a) Vectors

(b) Insects

(c) Pathogens

(d) Worms



1. Pathogens result in morphological and functional damage in our body.

2. Health is just absence of disease or physical fitness.

3. Infectious diseases are very common and every one of us suffers from these at some time or other.



1. Study of causes of disease is called.........

2. Among non infectious diseases ........... is major cause of death.





1. (d) All of these ( Infections, lifestyle, hygiene, regular exercise and mutations affect human health)


2. (a) cancer (Cancer is caused by carcinogens and is not communicable)


3. (b) Cholera (House fly carries Vibrio cholerae , Which is causative agent of Cholera.)


4 (a) Amoebiasis (Causative agent of this disease is Entamoeba hitolytica . When we wash our hands frequently, we can check spread of this disease. )


5. (c) Pathogens (Pathogens are organisms that cause diseases, like viruses, bacteria, fungi, protozoa and worms etc.)





1. True

2. False (Health is not just absence of disease or physical fitness, itis a

state of complete physical, mental, social and behavioral wellbeing.)

3. True



1. Etiology

2. Cancer


1. What measures would you take to prevent waterborne diseases?

2. List some diseases transmitted by houseflies.

3. In which way study of biology has helped us to control infectious diseases?


1. What are various public health measures which you would suggest to safeguard against infectious diseases?





The diseases, which are caused by pathogens and readily spread from infected to healthy persons, are called infectious or communicable diseases.When pathogens infect a person and start multiplying to produce toxins. Due to toxins some symptoms are produced. The interval between infection and

first appearance of disease is called the incubation period. Multiplication of

microorganisms goes on in the body then microbes may overcome the body's different system and the victim dies or the body defence system may overpower the pathogens and the patient recovers from the disease.


Some common diseases caused by pathogens are typhoid. malaria,pneumonia, amoebic dysentery, Dengue chikungunya, ascariasis and

filariasis etc.In this assignment, we will study Causing agent, mode of transmission,

symptoms and preventive measures of two diseases, TYPHOID and MALARIA.



Causative agent: Typhoid fever is caused by a rod shaped bacterium,Salmonella typhi.


Mode of transmission: The disease can spread through contaminated food and water and close contact with infected person. Houseflies may carry the pathogens, from the faeces to the food, milk and water. The bacteria enter via

mouth, reach the intestine and cause ulcers in intestinal wall.


Symptoms of typhoid: Signs and symptoms of typhoid usually include high fever, headache, dry cough, rashes, stomach pain and inflammation in intestine,constipation, diarrhoea, loss of appetite and weight loss.

Typhoid can be confirmed by Widal test.


Preventive measures: Typhoid fever can be prevented by improved sanitation,

safe drinking water, covered food and personal hygiene. Frequent hand wash is

best way to control the disease.


Control of Typhoid: Antibiotics can treat the disease. Typhoid vaccine is also available.



Malaria is a life threatening disease which is very common in tropical and subtropical regions. In 2019 there were an estimated 229 million cases of malaria worldwide.


Causative agent: Malaria is caused by the malarial parasite /asimodium sp.There are four species which cause Malaria: Plasmodium vivax, Plasmodium ovale, Plasmodium malariae, Plasmodium falciparum.Incubation period of malaria is about 10 to 14 days.


LIFE CYCLE OF PLASMODIUM:Life cycle of plasmodium completes in two hosts, therefore it is known as digenetic. Asexual phase of life takes place in human host and sexual phase in female Anopheles mosquito host. Hence mosquito is primary host, and Man is secondary host.


ASEXUAL CYCLE OR SCHIZOGONY in HUMAN HOST: When infected Female Anopheles mosquito bites humans, it injects sporozoites into the blood of man.


These sporozoites reach liver cells. This phase is called Exoerythrocytic Schizogony. The sporozoites become large and spherical and are called cryptozoites, which multiply by multiple fission to form cryptomerozoites and are released, when host cell ruptures. These cryptomerozoites attack RBC and

undergo erythrocytic Schizogony. In Erythrocytic Schizogony, the parasite

enters RBC, becomes spherical and takes food, it is called trophpzoite. It 

develops a large food vacuole and becomes amoeboid. The haemoglobin of RBC gets decomposed into a yellowish brown pigment haemozoin.


TROPHOZOITES undergoes multiple fission to form merozoites. These merozoites arrange themselves around the cytoplasm of RBC to give rise to rosette stage. The weakened RBC ruptures and symptoms of malaria appear.

Some merozoites change into sexual forms, male and female gametocytes. The further development takes place inside the gut to form sporozoites.



First step in sexual cycle is gametogenesis, which takes place inside the stomach of the mosquito. In Gametogenesis micro gaietccytsas divide to form 4 to 8 daughter nuclei, which ultimately form male gametes. Female gametocyte matures into a single macro gamete or ovum.


Fertilization Occurs in the stomach of mosquito to form zygote.This zygote becomes elongated worm like motile structure called ookinete and pierces the wall of stomach and becomes a spherical structure surrounded by cyst wall. It is now called oocyst.


Sporogony: The oocyst now undergoes asexual reproduction. It grows in size and develops a number of vacuoles and nucleus divides repeatedly to form a large number of daughter nuclei. The resulting cells are called sporozoites.Ultimately the oocyst ruptures and the sporozoites are set free in the body of the mosquito. From stomach sporozoites reach the salivary glands of the mosquito.

When this infected female Anopheles mosquito bites a person, sporozoites are injected into his or her body with Saliva.Symptoms of malaria: Symptoms of malaria include fever, chills, headache,nausea abdominal pain, muscle or joint pain, rapid breathing and cough.



1. Mosquitoes are most active in the moming and evening. Cover your skin, apply

insect repellent to skin when going outside.

2. Drain off stagnant water, or sprinkle kerosene.

3. Larvicidal fisnes can also be used.

4. Removing unnecessary vegetation around the houses.



1. Widal test is carried out to test:

(a) Malaria

(b) Diabetes

(c) Typhoid

(d) AIDS


2. Trophozoites, schizonts and gametocytes of all malarial parasites are seen in the peripheral blood smear except:

(a) P. falciparum

(b) P. vivax

(c) P.malanae

(d) P.ovale




3. Haemozoin is:

(a) A precursor of haemoglobin

(b) A toxin from streptococcus

(c) A toxin from plasmodium species

(d) A toxin from haemophilus species


4. Where will you look for the sporozoites of the malarial parasite?

(a) Saliva of the infected female Anopheles mosquito

(b) Red blood corpuscles of human suffering from malaria

(c) Spleen of infected humans

(d) Liver of infected human


5. Typhoid is also known as:

(a) Pneumonic fever

(b) Enteric fever

(c) Hepatic fever

(d) Vesical fever



1. Malarial parasite plasmodium reproduces sexually in human host.

2. Salmonella typhi bacterium is spherical in shape.

3. Microgametocyte and macrogametocyte produce male and female gametes in Plasmodium.




1. Female Anopheles mosquito takes up ................ With blood


2. Causative agent of Typhoid is..............





1. (c) Typhoid (Widal test is named after its inventor, Georges Fernand Widal is

confirmatory test for typhoid)


2.(a) Plasmodium falciparum ( Schizogony occurs inside the capillaries of the

internal organs like spleen, liver and bone marrow, only Signet ring form is found in

the peripheral blood smear.)


3. (c) A toxin from Plasmodium sp. ( Haemozoin is a disposal product formed by

digestion of blood by pathogens like plasmodium. )


4. (a) Saliva of the infected female Anopheles mosquito ( Mature sporozoites

leave the intestine and migrate to salivary glands of female Anopheles mosquito)


5. (b) Enteric fever ( because Enteric fever is a systemic disease characterized by

fever and abdominal pain.)



1. False; in mosquito host

2. False; rod shaped.

3. True



1. Male and female gametocytes

2. Salmonella typhi



1. Which organisms are primary and secondary hosts of malaria and why?

2. List some symptoms of typhoid fever.

3. How is Plasmodium falciparum most fatal?

4. How can Typhoid be prevented?



1. Describe the life cycle of Plasmodium vivax.





Respiratory diseases are those diseases which affect any part of respiratory system, nasal chamber, larynx, pharynx, bronchi, bronchioles, alveoli and the respiratory muscles of chest cage.Some common respiratory diseases are pneumonia, common cold, influenza,asthma, bronchitis and lung cancer etc. There are two types of respiratory

diseases and disorders: Infectious and chronic. Pulmonary infections are most

commonly bacterial or viral.



Pneumonia is a respiratory infection that affects the lungs.


Pneumonia is the single largest infectious cause of death in children.In lungs, small sacs like air filled structures called alveoli are present at the ends of bronchioles. In healthy person, these alveoli help in exchange of 

gases in respiration. But when individual has pneumonia, the alveoli filled with pus and fluid which makes breathing painful and oxygen intake

comes down. Anyone can get this lung infection but children younger than

14 years of age and people above 65 years of age are at higher risk. People with health cause weakened immune system are also susceptible to pneumonia.


CAUSATIVE AGENT OF PNEUMONIA: There are several types of infectious agents that can cause pneumonia.


Bacterial Pneumonia: The most common cause of bacterial pneumonia is Streptococcus pneumoniae. Other causes include Mycoplasma

pneumoniae, Haemophilus influenzae.


Viral pneumonia: Common causes of viral pneumonia are:




Influenza virus, SARS- CoV-2.


TRANSMISSION OF PNEUMONIA: Pneumonia is spread when droplets of fluid containing the pneumonia bacteria or virus spread in air when someone 

coughs or sneezes and then inhaled by others. Transfer of germs can also take place by touching the things contaminated with Pneumonia causing virus or

bacteria and then touching your mouth or nose.


SYMPTOMS OF PNEUMONIA: Pneumonia symptoms can be mild to life threatening. They include:


Cough with phlegm


Fever and chills (Fever 102 F or higher)


Shortness of breath and chest pain


Feeling of tiredness or fatigue


Nausea, vomiting


Loss of appetite




In severe cases lips and fingernails turn grey to bluish in colour.


PREVENTIVE MEASURES AND CONTROL: Risk of bacterial Pneumonia can be lowered by:


Washing hands frequently


Eat plenty of fruits and vegetables


Staying away from persons suffering from Pneumonia


Reducing away from Pollution


TREATMENT: Bacterial Pneumonia can be treated with antibiotics.Immunization against Hib, pneumococcus, measles and whooping

cough is the most effective way to prevent Pneumonia.




Common cold is a viral infection of upper respiratory tract (Nose and throat)

It is usually harmless. Healthy adults are expected to have 2 to 3 colds each

year. Infants and children can have even more frequent colds. Symptoms usually last for 3-7 days.


CAUSE OF COMMON COLD: Common cold is caused by more than 200 types of viruses, but the most common one is Rhinovirus. Cold begins

when virus attached to the lining of the nose or throat. Inflammation occurs in nose and throat, a lot of mucus is produced.The viruses which cause common cold are:

Human Rhinovirus, Parainfuenza virus, Adeno virus etc.


SYMPTOMS OF COMMON COLD: Signs and symptoms of common cold can


Runny or stuffy nose


sore throat


cough and congestion


mild headache and tiredness


Sneezing and low grade fever.




PREVENTION OF COMMON COLD:There is no vaccine for common cold but with using some precautions you can slow down the spread of cold. These are:


Wash your hands frequently.


Disinfect and clean the high touch surfaces.


Sneeze and cough into tissues and throw the used tissues in closed dustbins.


Don’t share your utensils with other members of the family when you have cold.





1. What are signs and symptoms of common cold?

(a) Runny nose and sore throat

(b) Ear pain

(c) Chills

(d) All of the above


2. Which of these microbes causes walking pneumonia?

(a) Klebsiella pneumoniae

(b) Streptococcus pneumoniae

(c) Mycoplasma pneumoniae

(d) Chlamydophila pneumoniae


3. What are symptoms of Pneumonia?

(a) Rash, painful joints and itching skin

(b) Jaundice and peeling skin

(c) Cough, fever and chills

(d) All of the above


4. Which disease is known as viral upper respiratory tract infection?

(a) Pneumonia

(b) Shingles

(c) Typhoid

(d) Common cold


5. The primary preventive strategies for community acquired

pneumonia is:

(a) Antibiotic therapy

(b) Immunization with pneumococcal and influenza vaccines

(c) Good hand hygiene

(d) Adherence to healthy lifestyle behaviours



1. You should expect your doctor to prescribe antibiotics for standard cold symptoms.

2. In common cold, the lips and fingernails may turn grey to bluish in colour.

3. As a result of pneumonia the alveoli get filled with fluid leading to severe problems in respiration.



1. Hib vaccine is used against.........

2. Causative agent of common cold is .................





1. (a) Runny nose and sore throat


2. (c) Mycoplasma pneumoniae (|In walking pneumonia symptoms are generally so mild that no hospitalization is required.)


3. (c ) Cough, fever and chills


4. (d) Common cold ( Common cold is a contagious upper respiratory infection that affects nose throat and sinuses)


5. (b) immunization with pneumococcal and influenza vaccines



1. FALSE: There is no vaccine or antibiotics for common cold.

2. FALSE: In severe cases of Pneumonia lips and fingernails turn grey to bluish in colour.



1. Haemophilus influenzae type b

2. Rhinovirus



1. What are the symptoms of walking pneumonia?

2. How common cold differs from pneumonia?

3. Why it is hard to cure common cold?



1. Describe cause, symptoms and prevention of Pneumonia.

2. Name Causative agent of common cold; write its symptoms and prevention.





GEE is an infectious tropical disease caused by any one of several thread-like parasitic round worms. The two species of worms most often associated with this disease are Wuchereria bancrofti and Brugia malayi. The larval form of the parasite transmits the disease to humans by the bite of a mosquito.

BE is a type of roundworm infection. These worms are parasites that use your body as a host to mature from larvae or eggs to adult worms. Adult worms, which reproduce, can be more than a foot (30 centimeters) long.



Elephantiasis is caused by three types of parasitic worms:


Wuchereria bancrofti


Brugia timori


Brugia malayi

These worms affect the lymphatic system that is responsible for removing the toxins

and wastes from the body. When the lymphatic system is blocked, it is unable to

remove toxins from the body. This results in the accumulation of lymphatic fluid that

causes swelling.When the infected Anopheles mosquitoes bite a healthy person, the larvae called microfilariae moves into the lymph nodes and develop into adult worms and persist for years.


TRANSMISSION: -Adult worms nest in the lymphatic vessels and disrupt the normal function of the lymphatic system. The worms can live for approximately 6—8 years and, during their lifetime, produce millions of microfilariae (immature larvae) that circulate in the blood.

Mosquitoes are infected with microfilariae by ingesting blood when biting an infected host. Microfilariae mature into infective larvae within the mosquito. When infected

mosquitoes bite people, mature parasite larvae are deposited on the skin from where

they can enter the body. The larvae then migrate to the lymphatic vessels where they

develop into adult worms, thus continuing a cycle of transmission.


Lymphatic filariasis is transmitted by different types of mosquitoes for example by

the Culex mosquito, widespread across urban and semi-urban areas, Anopheles,mainly found in rural areas, and Aedes, mainly in endemic islands in the Pacific.



The filariasis elephantiasis symptoms include:

Swelling in:










Damaged lymph system resulting in an impaired

immune system.


Repeated bacterial infections of the skin.





Initial symptoms are vague including high-fever, rashes and chills. At first, most of those afflicted believe they have caught

the Flu. Gradually, the lower torso- legs, sex organs,abdomen- start to swell out of

control. This swelling is so severe that most physicians have a tough time

controlling it. The skin around these swollen parts starts to itch and pain, besides becoming rough. Lumpy outgrowth on the skin on these parts is also common.


Since the Filariodidea parasites affect the lymphatic system first, there may also be

gradual swelling of lymph nodes of an affected individual's body. On occasions,

secondary bacterial infections have been noted on these regions of our bodies.

Elephantiasis is determined when blood samples are tested under high-powered

microscopes. The last stage- chronic lymphoedema- is usually when the disease

starts to develop rapidly.




The disease can be cured by drugs like Hetrazoan, MSE and Di Ethyl Carbamazine (DEC)


Reconstruction of affected body parts through surgery.


The disease can be prevented by taking precautions against mosquito bites.Ascaris has several species but they are all almost a type of parasitic nematode worm. The giant roundworm that infects the human intestine by entering through the route of fecal-oral has the scientific name of Ascaris lumbricoides.


These can grow up to a length of 14 inches or around 35cm long and 2-6 mm wide (depending on the gender of the parasite) inside the host body and causes the disease of roundworms]EEEE in humans. People are more affected by Ascariasis in areas with poor sanitation conditions, and it is a common infection occurring worldwide, which is more prevalent in tropical and subtropical countries. It is estimated that almost one-sixth of the human population gets infected

by HM disease.


You can become infected with ascariasis after accidentally ingesting the eggs of the A. fumbricoides roundworm. The eggs can be found in soil contaminated by human feces or uncooked food contaminated by soil that contains roundworm eggs.Children often become infected when they put their hands in their mouths after playing in contaminated soil, according to WHO. Ascariasis can also be passed directly from person to person.


One of the characteristics of Ascaris is that the adult female organism releases the

eggs, and at a time their uteri contain 27 million eggs, with almost 2 lakh eggs being

laid by them every day for 12-18 months. The roundworm life cycle also has the step

where the eggs are shed by the feces of an infected person and flies might carry the

eggs of the parasite to a healthy person.


Fertilized eggs depend on the changes of the environmental conditions to an embryo

and become infective in almost 18 days and they can persist in the optimum, moist,

and shaded soil for ten years almost or more.

The eggs of the parasite enter the human body from the mouth and are ingested through contaminated food or water. These eggs when it enters the body, then develops into a Rhabditiform larva and hatches and penetrates the gastrointestinal tract walls and enters into the bloodstream.These larvae move through the bloodstream and enter the lungs and break into the alveoli, after maturing the roundworms in a human move up the trachea where they are coughed up to be swallowed again, and this is how the eggs reach the small intestine. And after passing three weeks in the stomach, the roundworms in

humans develop into adult female or male worms, and in the small intestine, they

mate to lay more eggs.People with ascariasis often have no symptoms. Symptoms become more noticeable when the roundworm infestation grows.Roundworms in your lungs can cause:


coughing or gagging


wheezing or shortness of breath


aspiration pneumonia (rarely)


blood in mucus


chest discomfort


fever Roundworms in your intestines can cause:






irregular stools or diarrhea


intestinal blockage, which causes severe pain and vomiting


loss of appetite


visible worms in the stool


abdominal discomfort or pain




growth impairment in children due to malabsorption


Some people with a large infestation may have other symptoms,such as fatigue and fever. A major infestation can cause extreme discomfort. You may have all or many of the above symptoms if you don’t receive prompt treatment.


Always wash your hands with soap and water before eating


Boil or filter your water Avoid unclean common areas for bathing


Peel or cook unwashed vegetables and fruits in regions that use human faeces for fertilizers






1. The causative of filariasis is:

a) Schistosome

b) Trichinella

c) Culex

d) Wuchereria


2. Which is helminthic disease:

a) Polio

b) Filariasis

c) Lepeosy

d) Amoebiasis


3. Infection of ascariasis usually occur by:

a) Mosquito bite

b) Drinking water containing eggs of ascariasis

c) Injection of dead pathogens

d) IfB & Tlymphocytes damage


4. Filarial larva can be collected from man’s:

a) Peripheral blood at midnight

b) Smear of spleen

c) Smear of intenstinal contents

d) Biopsy of liver


5. Which drug is used to treat lymphatic filariasis caused by Wuchereria


a) Albendazole

b) DEC

c) Lavermectin

d) Doxycycline


Fill ups:

1. Ascariasis is caused by .

2. Filariasis is also called ;

3. Filariasis can be controlled by taking precautions against .



Ascariasis is caused by contaminated soil water, vegetables etc.


Elephanteases in caused by filarial worm Wichereria boncrofli






1. (d) Wuchereria most cases the filariases is caused by the parasite known as

Wuchereria bancrofli


2. (b) filariasis. Filaria is a helminthic disease


3. (c) Drinking of water containing eggs of ascaris


4. (a) Peripheral blood at night . Adult parasite produce microfilariae which

circulate in the peripheral blood usually at night.


5. (b) DEC


Fill ups:

1. Ascarids (common round worms)

2. Elephantiasis

3. Mosquito bites



1. True. Eggs of the parasite are present in contaminated soil

2. True One can say that the lymphatic filariasis which is also called as

elephantiasis is a type of parasite disease.



1. List some symptoms of ascariasis.

2. How is filariasis transmitted?

3. Give the scientific name of organism that causes filariasis.


1. Name the causative agents, symptoms and cure for the following


(i) Filaria (Elephantiasis) (ii) Ascariasis





Amoebiasis is also known as amoebic dysentery. It is caused by a protozoan

parasite of the human large intestine, Entamoeba histolytica. They are

cosmopolitan, they live in the large intestines and produce eggs or cysts,

which are passed out of the body with the stool. It results in diarrhoea and



Dermophytoses are Ringworm or round red and silvery type of superficial FUNGAL infections of the skin. Heat and moisture promote the growth of these fungi.




AMOEBIASIS is caused by the following ways:


1. Living in areas with poor sanitary conditions.


2. Ingesting water or food, contaminated by faeces of infected people.


3. By swallowing cysts of the parasite.


4. It can also occur by oral-anal sexual contact with an infected person.

Inside the intestine the parasite secretes an enzyme Cytolysin that dissolves the wall of large intestine. The feeding stage of parasite is called Trophozoite.



An individual infected with E. histolytica may have mild to severe symptoms.

Sometimes a person may show no symptoms of the disease:








Weight loss


Abdominal discomfort


Diarrhoea that may include blood or mucus with periods of constipation.


TREATMENT OF AMOEBIASIS:Symptomatic amoebiasis can be treated with administration of metronidazole,followed by eliminating any organisms present in the colon by a luminal amoebicide.Asymptomatic carriers are treated by giving a luminal amoebicide.

This reduces the risk of transmission.



Ringworm, also known as dermatophytosis, is a fungal infection of the skin. It

can affect both humans and animals. The infection initially appears as red

patches on the affected areas that later spreads to different areas of the body.

It majorly affects the scalp, nails, feet, groin and beard.The ringworm fungus grows well in moist environment such as showers,

bathroom floors and walls, swimming pools and also in between the skin folds. The vectors for this disease include pets such as cats and dogs. There are multiple forms of ringworm fungi, which affect different body parts.Tryptophyton rubrum, T. mentagrophytes, T.tonsurans, Microsporum andoninni, Epidermophyton floccosum etc.



Ringworm can be caused by the following ways:

It spreads by skin contact with an infected person.


It spreads from pets and cows.


The fungus causing ringworm might be found lingering on clothes,comb, towels and brushes.


These fungi are mainly present in the spores of soil. Coming into contact with such soil will result in an infection.


SYMPTOMS OF RINGWORM:Ringworm symptoms vary depending upon the site of infection.The following are the common characteristic symptoms of rinqworm:


1. The skin of the feet becomes swollen and itchy between the toes. The soles and heels of the feet may also be affected.


2. Itchy, scaly red spots appear on the groin area.


3. Ringworm appears like an itchy, scaly, inflamed bald spot on the scalp.


4. Ringworm on nails appear to be thick and abnormal in colour and shape.


5. In the beard, itchy, red spots appear on the chin, cheeks, and the upper neck.


RINGWORM TREATMENT:A variety of products to treat ringworm infections are available in the market, such as antifungal cream, lotion, and powder. Sometimes, even home remedies are very effective.


1. The best antifungal creams used for this infection are Miconazole or Terbinafine, which should be applied twice in a day on the infected region until the symptoms withdraw.


2. Amphotericin B is a very powerful fungicide that is used in the most serious cases of fungal infections.


3. There are many home remedies which help to prevent and control the infections. Using talcum powder is recommended as it helps to control sweating


4. Home remedies include Neem, which is a particularly effective antimicrobial and antifungal agent


RINGWORM PREVENTION:Following precautions is one of the best methods to avoid ringworms.

And more than often, lifestyle choices and decisions affect how the disease is spread. For instance, obesity increases the risk of ringworm.

1. Maintain cleanliness and hygiene.

2. Wash hands with sanitizers.

3. Wear clean ironed clothes.

4. Avoid using communal pools.

5. Wear loose-fitting cotton clothes to avoid the accumulation of sweat

6. The skin folds have to be kept clean regularly to avoid the accumulation

of sweat and dirt between the creases.

7. Having a shower twice a day is also recommended.

8. Not touching or scratching the itchy red patches would help to prevent it

from spreading.



1. Amoebiasis is known to cause:

(a) Headache

(b) Convulsions

(c) Dysentery

(d) None of the above


2. Causative organism of Amoebiasis is:

(a) Ascaris lumbricoides

(b) Toxoplasma gondii

(c) Entamoeba histolytica

(d) None of the above


3. The feeding stage of Entamoba histolytica is:

(a) Minuta form

(b) Magna form or Trophozoite

(c) Sporozoite

(d) None of the above


4. Which of the following is not the species of ring worm?

(a) Trichophyton

(b) Microsporum

(c) Plasmodium

(d) Epidermophyton


5. The most common site for amoebiasis is:

(a) Caecum

(b) Sigmoid colon

(c) Transverse colon

(d) Hepatic flexure



1. Entamoeba histolytica cysts have nuclei.

2. Ring worm is also known as .



1. Ringworm is caused by a fungus.

2. Animals can transmit ringworm to people.




1. (c) Dysentery

2. (c) Entamoeba histolytica

3. (b) Magna form or Trophozoite

4. (c) Plasmodium

5. (a) Caecum; the first part of large intestine.



1. 1-4

2. Dermatophytoses



1. TRUE. Ringworm, despite the name, is not caused by a worm. Rather, it is

a skin infection caused by a fungus.

2. TRUE Different kinds of animals can transmit ringworm infection to people,

particularly kittens and puppies.




1. Give the causative agent of ringworm.

2. How transmission of Amoebiasis and Ringworm takes place?


3. Write the scientific name of the causal organism of Ringworm in human.



1. Name the causative agents, symptoms and cure for the following diseases

(i) Amoebiasis (ii) Ringworm








The overall ability of the body to fight against disease causing microorganisms with

the help of immune system is called IMMUNITY.

Immunity is of two types-

1. Innate immunity.

2. Acquired immunity.


The system that includes specialized cells, tissues and organs involved in

protecting our body against invading pathogens is called the IMMUNE SYSTEM.


INNATE IMMUNITY:The immunity which occurs by birth is called innate immunity.Innate immunity is non-specific type of defense.

Innate immunity consists of various barriers which prevent the entry of microorganisms into the body.


Innate immunity consists of four types of barriers:


PHYSICAL BARRIERS-Skin on our body is the main barrier which prevents entry of the micro-organisms and mucus coating of the epithelium lining the respiratory, gastrointestinal and urogenital tracts also help in trapping microbes entering our body.


PHYSIOLOGICAL BARRIERS- Acid in the stomach, saliva in the mouth,tears from eyes—all prevent microbial growth.


CYTOKINE BARRIERS- Virus-infected cells secrete proteins called interferons which protect non-infected cells from further viral infection


CELLULAR BARRIERS - Certain types of leukocytes (WBC) of our body like polymorpho-nuclear leukocytes (PMNL-

neutrophils), monocytes and natural killer (type of lymphocytes) in the blood as well as macrophages in tissues can phagocytose and destroy microbes.



The immunity which develops during lifetime by exposure to suitable foreign agents like microorganisms is called acquired immunity.Acquired immunity is pathogen specific and it is characterized by memory.

When the body first encounters a pathogen it produces a response which takes long time to develop and of low intensity called as primary immune response and if the body encounters the same pathogen again it produces highly intensified and

quick response called as secondary immune response.After responding to the foreign microorganisms and elimination of the pathogen,the immune system keeps the memory of the that encounter (primary response)

and during its second encounter with the same pathogen produces a highly intensified immune response (secondary response).


The primary and secondary immune responses are carried out with the help of

two special types of lymphocytes present in our blood-


B-lymphocytes :The B-lymphocytes produce an army of proteins in response to pathogens into our blood to fight with them called as antibodies.


T-lymphocytes: The T-cells themselves do not produce antibodies but help B- cells to produce them.





1. Which of the following systems protects our body against disease-causing microbes?

(a) Immune system

(b) Digestive system

(c) Excretory system

(d) Respiratory system


2. Which of the following immunity is present from our birth?

(a) Innate Immunity

(b) Active immunity

(c) Passive immunity

(d) Acquired immunity


3. B-cells and T-cells are two types of cells involved in .

(a) Innate Immunity

(b) Active immunity

(c) Passive immunity

(d) Acquired immunity


4. Which of the following immunity is obtained during a lifetime?

(a) Innate immunity

(b) Active immunity

(c) Passive immunity

(d) Both (b) and (c)


5. Which of the following immunity is called the first line of defence?

(a) Innate Immunity

(b) Active immunity

(c) Passive immunity

(d) Acquired immunity


Fill ups:

1. The branch of biology involved in the study of immune systems in all organisms is called .

2. The common disorders caused by a poor immune system include

3. Vaccination leads to the production of B and T cells.



1. T- Cells are involved in self mediated immunity.

2. Only invertebrates have specific immune responses.



1. (a) Immune System

2. (a) Innate Immunity

3. (d) Acquired Immunity

4. (d) Both (b) and (c)

5. (a) Innate Immunity


Fill ups:

1. Immunology

2. Epidemic diseases

3. Memory. Vaccination works to stimulate a specific immune response that will

create memory B and T cells specific to a certain pathogen.



1. True.

2. False


1. What do you mean by passive immunity?

2. Name various types of barriers of Innate Immunity?

3. Distinguish between B- cells and T- cells?


1. What is Immune System? Mention 2 types of Immune system and explain.






Have you ever wondered that why the widely prevalent covid 19 infection can infect

an individual after inhaling the virus and not through the skin????

Just by touching the virus contaminated secretions, one cannot get the infection,

unless the individual touches his nose or mouth or eyes with his contaminated



Well dear students, the answer lies in the fact that skin is a part of “innate immunity”

and forms a barrier for entry of organisms.

We will now study more about INNATE IMMUNITY.


INNATE IMMUNITY:This type of immunity is present right at the time of birth, and includes different barriers. These barriers include:


1) Physical barriers: This includes epithelium lining of skin, respiratory tract,

urogenital system and gastrointestinal system. This is the reason that COVID-

19 cannot enter the body by just touching virus contaminated secretions.However, this is not a fool proof method as you very well know that certain viruses like coronavirus and influenza can enter through respiratory lining.


2) Physiological barriers: This includes things like tear film, saliva and acid in

stomach. The food we eat contains many bacteria, but we seldom fall ill by

eating food. The acid in stomach kills many of the micro-organisms in the food. In fact, people who eat antacid tablets are more likely to fall sick to organisms like salmonella typhoid (the causative organism of typhoid).


3) Cellular barriers: These include the WBCs of the body like Granulocytes, NK

(Natural Killer) cells and Macrophages.

They patrol the body looking for any micro-organisms and kill them.Patients (like cancer patients) often have low level of WBCs and have more chances of falling ill than healthy population.It is important to note that B-lymphocytes and T-lymphocytes don't form

part of innate immunity. They are a part of acquired immunity and will be discussed in a later module.


It is also important to know that cells of innate immunity lack the property of “memory”. That is each time the neutrophils encounter a pathogen, they will react in same way.


This is unlike the cells of acquired immunity which learn from previous infections (memory) and react in more robust way in any subsequent infections.


4) Cytokine barriers: Cytokines are non-antibody proteins, released by the cells

in response to contact with an antigen.

Whenever a virus infects a cell, it produces chemicals like interferons; the lycoproteins, which guard the neighbouring cells that a virus has entered the field and the cells then prepare for a potential future infection.


Inflammatory Barrier is formed in response to tissue injury or at the site of infection, which is manifested as redness, swelling, pain and heat. The damaged Mast cells of connective tissue and Basophils of blood produce chemical alarm signals in the form of Histamine and Prostaglandins. Both

plasma and phagocytes come out of the blood. Serum proteins in plasma has antibacterial properties. Phagocytes destroy the invading microorganisms.





1) Skin covering the body is an example of barrier.

a) Physical

b) Physiological

c) Cellular

d) Cytokine


2) Acid secretion of stomach is an example of barrier.

a) Physical

b) Physiological

c) Cellular

d) Cytokine


3) Neutrophils are an example of barrier.

a) Physical

b) Physiological

c) Cellular

d) Cytokine


4) Virally infected cells produce chemicals called as to protect surrounding non-infected cells.

a) Prostaglandins

b) Interferons


d) Histamine


5) NK cells are a part of immunity.

a) Innate

b) Humoral

c) Acquired

d) Cellular



1. B-lymphocytes are part of innate immunity.

2. Eosinophils are an example of innate immunity.

3. Innate immunity cells don’t have “memory”



1. The four type of barriers ofinnate immunity are. =, sand

2. immunity is non-specific and present right at birth.





1) (a) Physical. Skin, epithelium of GI system, genital system and respiratory system form part of physical barrier.


2) (b) Physiological. Acid in stomach, tears and saliva are part of physiological barriers


3) (c) Cellular. Cells of innate immunity are granulocytes (neutrophils,eosinophils, bas1zophils), macrophages, NK cells.


4) (b) Interferons Virally infected cells produce interferons to protect the

surrounding non-infected cells


5) (d) NK cells. Cells of innate immunity are granulocytes (neutrophils,eosinophils, basophils), macrophages, NK cells.


(ii) TRUE / FALSE:

1) False. Cells of innate immunity are granulocytes (neutrophils, eosinophils,

basophils), macrophages, NK cells. B- lymphocytes and T-lymphocytes are

examples of acquired immunity.


2) True. Cells of innate immunity are granulocytes (neutrophils, eosinophils,

basophils), macrophages, NK cells


3) True. Memory is a feature of acquired immunity.



1) The four type of barriers of innate immunity are physical, physiological,

cellular and cytokine barriers.

2) Innate immunity is non-specific and present right at birth.


1. What are interferons? How do interferons check infection of new cells?

2. Write a short note on cellular barriers with respect to immunity.



1. What are the four types of barriers of innate immunity? Briefly describe each

of them with relevant examples.




Have you ever wondered; why when someone has second infection of COVID -19,it is usually milder than the first infection????

It is because the body's immune system learns about the virus from the first infection, and is well prepared when the body gets infected second time.In other words, we can say that that body has “acquired” the immunity from the first infection. We will learn more about acquired immunity in this module.“Acquired” means something (antigen or antibody) enters the body from outside and produce immunity.



It is the immunity or resistance to a disease which develops during lifetime of an

individual by obtaining or producing self-antibodies and cells against the specific

microorganism.It is a pathogen specific immunity. When the body gets infected by a pathogen for the first time, it generates a very mild response. This is called primary

response. On subsequent encounter by the same pathogen, the body generates a much stronger immune response. Our body has “memory” of the first infection and is better prepared to fight off the infection the second time, secondary response.


MECHANISM:The primary and secondary immune responses are carried out with the help of two special type of lymphocytes B and T in our blood.


1. Humoral or AMIS (Antibody Mediated Immune System)It is carried out with the help of activated B — cells and Antibodies.

There are 4 kinds of antibodies in the blood,

namely IgG, IgA, IgM, IgE (remembered by

the acronym GAME). All four antibodies are

produced from the B-lymphocytes.

When the body encounters the pathogen

the first time, the primary response of B-

cells is to generate the IgM antibody.

Helper T-lymphocytes then get activated

and after about 2 weeks, they help B-cells

to produce IgG.So, the initial response is milder as only IgM is produced but after about 2 weeks,the IgG antibodies are also produced and the patient gets cured of the illness.


On subsequent exposure to the same pathogen, the body quickly responds by generating lots of IgG within 1-2 days, and the pathogen gets killed, thus resulting in a very mild infection the second time. This is called as secondary or anamnestic response. This type of immune reaction is called humoral immune

response, or AMIS ( Antibody Mediated Immune System) as the antibodies are released into the blood. (The word “humor” is Latin for ‘bodily fluids’).



There is also a second type of immune response called as cell-mediated immune

response. Unlike humoral, there is no role of antibodies.In cell mediated immunity, the T-cells activate certain cells like macrophages to kill the pathogen infected cells. T- Cells are of four types: Helper, Killer or Cytotoxic,Supressor and Memory T- cells.

Since in this type of immune response, the pathogen is killed by cells, so itis

called cell-mediated immune response.

There is also a down side to cell mediated immunity.


Some patients suffer organ failure e.g. kidney or heart failure. They then require

organ transplant. But it is seen that only the organs from closely related donors

(e.g. first degree relatives) survive for long periods. The T-cells can recognize if the transplanted organ is from unrelated source and generate immune response in an

attempt to kill the organ. Even when the graft is from a close relative, the patient

needs to take immune system suppressing drugs so that T-cells are weakened and

don't attack grafted organ. This makes us realize that the T-cells can distinguish

between “self-proteins” and “nonself-proteins”.It is the cell-mediated immunity that leads to graft rejection (particularly the T-cells)




antibodies are produced inside the body. It requires long time to develop. It

may last for few months to life time.


2. ACQUIRED PASSIVE IMMUNITY: It is acquired due to obtaining readymade ANTIBODIES from OUT SIDE. Foetus obtain antibodies from

mother. Antisera are inoculated for avoiding contraction of disease like antirabies, antitetanus. It develops quickly. It does not last long.






1) Which of the following play a role in humoral mediated immunity?

a) B-lymphocytes

b) T-lymphocytes

c) Both AandB

d) None of the above


2) Which of the following play a role in cell-mediated immunity?

a) B-lymphocytes

b) T-lymphocytes

c) Both A and B

d) None of the above


3) Which of the following are the primary mediators of humoral immune response?

a) Antibodies

b) Neutrophils

c) T-cells

d) NK cells


4) Which cells are primarily responsible for graft rejection?

a) T-cells

b) Neutrophils

c) B-cells

d) Antibodies


5) The body gets infected by a pathogen that stays inside cells and does not in the blood. Which type of immune response will lead to resolution of the infection?

a) T-cells

b) Neutrophils

c) B-cells

d) Antibodies




1) Primary response to infection is much stronger than the delayed response.

2) Both cell-mediated and humoral-mediated immune system show property of “memory”.

3) Antibodies are produced by the T-cells.



1) Subsequent encounter with the same pathogen elicits a highly intensified

secondary or response.

2) are the cells which help B-lymphocytes to produce antibodies.





1) (a) c) Both A and B. Humoral immune response is the one where antibodies are produced. B-lymphocytes produce the antibodies. However, it is the T-cells which help them to produce the antibodies


2) (b) T-lymphocytes. T-lymphocytes are the key mediators of cell-

mediated immunity


3) (c) Antibodies. Humoral immune response is the one where antibodies

are produced. B-lymphocytes produce the antibodies.


4) (a) T-cells Cell-mediated immunity is responsible for graft rejection. T-

cells mediate cell-mediated immunity


5) (a) T-cells. The pathogens which enter live in the blood will be targeted by

the humoral immune system (antibodies). However, the pathogens which live

inside the cells will be killed by the cell-mediated immunity(T-cells)



1) False. Secondary response or anamnestic response is much stronger than the primary response.

2) True. Both cell and humoral immunity show memory as it a property of acquired immune system.

3) False. Antibodies are produced by the B-cells (humoral immune system)


(ll) FILL UPS:

1) Subsequent encounter with the same pathogen elicits a highly intensified

secondary or anamnestic response 2) I-lymphocytes are the cells which help B-lymphocytes to produce antibodies.



1) What does the term ‘memory’ of the Immune system mean?

2) For an organ transplant, it is an advantage to have an identical twin. Why?



1) What is the role of B-lymphocytes and T-lymphocytes in the defence of the body against pathogens?





In the previous module, we learnt about the ACQUIRED IMMUNITY. We also learnt that B-cells are responsible for production of antibodies. Antibodies are Glycoproteins called Immunoglobulins, having specific aminoacid sequence to interact with specific Antigen. Antibodies form about 20% of the plasma proteins.In this module we will learn about the structure of the antibody.


STRUCTURE OF ANTIBODY:There are FIVE types of antibodies namely IgG, IgA, IgM and IgE (remembered by the acronym GAME) and Ig D. Each of the 5 antibodies has slightly different structure. However, for our purpose, we will study only the structure of IgG.


The IgG is a Y-shaped protein. The upper two ends of the molecule are called

antigen binding sites, and abbreviated as Fab(antibody binding fragment), and the

lower end is called Fe fragment (crystalline fragment). Each antibody molecule has

four peptide chains, two small called light chains and two longer called heavy

chains. The IgG antibody also has abundance of disulphide bonds.



The antibodies inactivate the antigens through different processes like;


NEUTRALISATION: Antibodies cover the toxic sites of antigen and neutralise them by acting as antitoxins.


AGGLUTINISATION: The antibodies bring about surface changes in antigens and they get clumped or agglutinated.


OPSONISATION: Antibodies known as OPSONINS get adhere to the surface of antigens. This make the antigens easily visible to the Phagocytes.


PRECIPITATION: The antibody make the soluble antigen heavier and make them

to setelled down or get precipitated.


LYSIS: The Lysin antibodies come in contact with the antigen containing cells, and

bring about rupturing of their surface covering.

The antigen binds to the antigen binding site and is removed from circulation.


(i) Multiple Choice Questions


1) The antibody is made up of how many peptides?

a) One

b) Two

c) Three

d) Four


2) The antigen binding site of antibody is made up of:

a) Light chain

b) Heavy Chain

c) Both light and heavy chains

d) None of the above


3) The shape of IgG antibody is:

a) X- shaped



d)L- shaped.


(ii) True/ False

1) Antibody is made up of polysaccharides.

2) Antibody molecule contains a lot of disulfide bonds.


(ii) Fillin the blanks

1) The five antibodies are,__and_.

2) The antibody is made up of a total of __ heavy and __ light chains.



1) (d) Four. The antibody has four peptide chains, the two small called light

chains and two longer called heavy chains.

2) (c) Both heavy and light chains. The antibody binding region (Fab) is

made up of two heavy and two light chains.

3)  (c) Y- shaped.


(ii) TRUE / FALSE:

1) False. Antibodies are made of peptides, and not polysaccharides.

2) True. Both the light chains and heavy chains are stabilized by disulphide




1) The four antibodies are IgG, IgA, IgM, IgE

2) The antibody is made up of a total of two heavy and two light chains.



1) Draw a labelled structure of antibody.

2) What do you mean by Opsonins?



1) Explain different processes of Antigen — Antibody interaction.





IMMUNITY is the ability to resist a particular pathogen.When a host is exposed to antigens, which may be in the form of living or dead microbes or other proteins, antibodies are produced in the host body; this type of immunity is called active immunity.Active immunity is slow and takes time to give its full and active response.

When readymade antibodies are given directly to protect the body against foreign

agents, it is called passive immunity.

Passive Immunity is fast and gives quick response to fight infection.The yellowish fluid colostrum, the first milk secreted by mother during the initial days of lactation has abundant antibodies IgA to protect the infant.The foetus also receives many antibodies from the mother through the placenta during pregnancy these are examples of passive immunity.

The foundation of IMMUNOLOGY through vaccination and other procedures were laid by the following scientists:


Edward Jenner found that milkmaids often develop a milder form of pox called

small pox. He coined the term Vaccine.

Louis Pasteur develops technique of weakening pathogen by starvation, heat or

cold.Robert Koch is famous for Germ Theory of disease and method of obtaining pure

cultures of pathogen.Emil Adolf Von Behring proposed that blood and serum of an immunised

person when injected to other, it brings about immunisation.Vaccination is a deliberate exposure to a pathogen in order to bring about immunity.The principal of immunisation or vaccination is based on property of memory of the immune system.

In vaccination a preparation of antigenic proteins of pathogen or inactivated

weakened pathogens (vaccine) are introduced in the body.


The vaccines also generate B and T cells that recognize the pathogens quickly on

subsequent exposure and counter the invaders with production of antibodies.


B and T cells are also called memory cells of the body.


In case of deadly infection like tetanus when a quick immune response is required

preformed antibodies is injected. This type of immunisation is called passive



Essentially, a vaccine imitates an infection triggering an immune response,without making a person sick.Recombinant DNA Technology has allowed the large scale production of

antigenic polypeptides of pathogens in bacteria or yeast.Vaccines produced using this approach allow large scale production and hence greater availability for immunization.Before vaccines many children died that vaccines now prevent whooping cough,measles and polio. Causative germs of these diseases still exist but because of

effective vaccination these are no longer a danger now.






1) Immunity is mainly of:

(a) 2 types

(b) 3 types

(c) 4 types

(d) 5 types




2) The material introduced in the body, in active immunity:

(a) Particular dead pathogen



(d) Catalyst


3) Introduction of readymade antibodies into the body is called:

(a) Active immunity

(b) passive immunity 

(c) disease

(d) None of these


4) Colostrum, first milk of mother after parturition is rich in:

(a) Antibodies

(b) antigens

(c) vitamins

(d) pathogens


5) Vaccination is a deliberate attempt to bring:

(a) Disease

(b) immunity

(c) allergy

(d) none of these



1) Immunity is to diseases.

2) Vaccination also generates and cells which recognize the pathogens quickly.

3) B and T cells are also called cells of the body.



1) Immunity is resistance of the body to a particular pathogen or disease.

2) In active immunity readymade antibodies are introduced in the body.

3) Colostrum is rich in antibodies.



1) (a) 2 (Active and Passive immunity. )


2) (a) Particular dead pathogen.( In active immunity a deliberate exposure to dead pathogen is made)


3) (b) Passive immunity ( Readymade antibodies are given in passive immunity)


4) (a) Antibodies ( Colostrum is called first milk of mother after delivery)


5) (c) Immunity ( Vaccination is based on the property of memory of the immune system)





1) resistance

2) BandT

3) memory



1) True

2) False ( In active immunity dead or inactive pathogen is introduced in the


3) True



1) Define immunity.

2) What is vaccination?

3) Name some diseases for which vaccination is available for newly born babies.



1) Explain immunity and its types.

2) What is importance of vaccination in providing immunity?









The human immune system consists of lymphoid organs, tissues, cells and soluble molecules like antibodies.Lymphoid organs are the organs where origin and/or maturation and

proliferation of lymphocytes occur.

The primary lymphoid organs are Bone Marrow and Thymus where lymphocytes differentiate into antigens sensitive lymphocytes.


After mutation lymphocytes migrate to secondary lymphoid organs like Spleen Lymph Nodes,Tonsils, Peyer's Patches of Small Intestine and Appendix. The secondary lymphoid organ provides the sites for the

interaction of lymphocytes with the antigen, which then proliferate to become effector cells.


The bone marrow is the main lymphoid organ where all blood cells including lymphocytes are produced.


The THYMUS is a lobed organ located near the heart. Both bone marrow and thymus provide micro environment for the development and mutation of T lymphocytes.


The spleen is a large bean shaped organ. It acts as a filter of the blood by

trapping blood borne micro-organisms. The lymph nodes are small solid structures located at different points along the lymphatic system. Lymph nodes serve to trap the micro-organisms or other antigens which enters into lymph and tissue fluid.


There are lymphoid tissues which are located within the lining of major tracts (respiratory, digestive and urine genital tracts) called Mucosa Associated Lymphoid Tissues (MALT). It constitutes about 50 % of lymphoid tissues in human body.





1) The human immune system consist of:

(a) Lymphoid organs

(b) Tissue cells

(c) Antibodies

(d) All of these


2) Bone marrow is a:

(a) Primary lymphoid organ

(b) Secondary lymphoid organ

(c) Tertiary lymphoid organ

(d) None of these


3) Spleen is a:

(a) Primary lymphoid organ

(b) Secondary lymphoid organ

(c) Tertiary lymphoid organ

(d) None of these


4) The site of interaction for lymphocytes and antigens are:

(a) Primary lymphoid organ

(b) Secondary lymphoid organ

(c) Stomach

(d)None of these


5) All blood cells are produced in:

(a)Bone marrow

(b) Spleen

(c) Thymus

(d) Tonsils



(a) Bone marrow and thymus are ............ lymphoid organ.

(b) Spleen and tonsils are ............... lymphoid organs.

(c) Spleen is a large .............. shaped organ.



(a) Bone marrow is the site for production of lymphocytes.

(b) Spleen is a primary lymphoid organ.

(c) Peyer's patches are present in the small intestine.






1) (d) All of these(Lymphoid organs, tissue cells, antibodies all constitutes make immune system)


2) (a) Primary lymphoid organ( Bone marrow is a primary lymphoid organ)


3) (b) Secondary lymphoid organ(Spleen is a secondary lymphoid organ)


4) (b) Secondary lymphoid organ(These organs are interaction sites for lymphocytes and antigens)


5) (a) Bone marrow( All blood cells are produced in bone marrow)



a) Primary lymphoid organs

b) Secondary lymphoid organs

c) Bean shaped



a) True

b) False(Spleen is a secondary lymphoid organ)

c) True



l) Name two primary lymphoid organs.

ll) Name two secondary lymphoid organs.

Il) Write full form of MALT.



l) Write about primary lymphoid organs and their functions.

ll) Explain the function of secondary lymphoid organs.




Immune system is a body’s defence against infection and other harmful invaders.

Without it the body would constantly get sick from germs such as bacteria or virus.

Immune system is made up of special cells tissues, organs that work together to

protect the body.When immune system does not work the way it should, it is called an immune system disorder.



Some common examples of immune system disorder are:

1) Severe combined immune deficiency. ( SCID)

2) Temporary acquired immune deficiencies.

3) Auto immune disorder



1) Severe Combined Immune deficiency (SCID): This is an example of immune deficiency that is present at the time of birth. Children are in constant danger of infections from bacteria, viruses and fungi. This disorder is sometimes called “Bubble boy disease”.


2) Temporary acquired immune deficiency: Immune system can be weekend by certain medicines for example this can happen to people on chemotherapy or other medicines used to treat cancer.


3) Auto immune disorder: In response to an unknown trigger, the immune system may begin producing antibodies that instead of fighting infections attack the body’s own tissues. Treatment for auto immune diseases generally

focuses on reducing immune system activities. Examples of auto immune diseases include:

Rheumatoid arthritis, lupus, multiple sclerosis.


4) AIDS: HIV which causes AIDS is an acquired viral infection that destroys important white blood cells and weakens the immune system.



The word AIDS stands for Acquired Immune Deficiency Syndrome.Syndrome means a group of symptoms. AIDS was first reported in 1981.



AIDS is caused by the Human Immune deficiency Virus (HIV), a member of a group of viruses called RETRO VIRUS, which have an envelope enclosing RNA genome.Transmission of HIV infection generally occurs by:

a) Sexual contacts with infected person.

b) By transfusion of contaminating blood.

c) By sharing infected needles.

d) From infected mothers to her child.


It is important to note that HIV /AIDS is not spread by mere touch or physical contacts, it spreads only through body fluid, so HIV/AIDS patients should not be isolated from family and society.


MECHANISM OF INFECTION:There is always a time lag between the infection and appearance of AIDS symptoms. This period may vary from a few months to many years (5 to 10 years).

After getting into the body of the host, the virus enters into macrophages where

RNA genome of the virus replicates to form viral DNA with the help of enzyme

Reverse Transcriptase.This viral DNA incorporates into host cell's DNA and directs the infected cells to produce virus particles. The microphages continued to produce virus and in this way acts like an HIV factory. HIV enters helper T- lymphocytes leading to decrease in their numbers which cause lot of infections to the host body.



A widely used diagnostic test for AIDS is Enzyme Linked Immune Sorbent Assay

(ELISA). Treatment of AIDS with anti-retroviral drugs is only partially effective.

They can only prolong the life of patient but cannot prevent death which is



Prevention is the best option for AIDS. HIV infection spreads due to conscious

behaviour pattern and is not something that happens in advertently like pneumonia

or typhoid.



Use a condom during sexual intercourse.


Avoid sharing syringes.


When getting a tattoo or piercing, make sure the material is new and disposable or sterilized.


 Use disposable gloves when at risk of direct contact with blood.


For HIV positive women, consider giving birth by caesarean section.In our country the National AIDS Control Organisation (NACO) and other Non- Government Organisations (NGO'S) are doing a lot to educate people about AIDS.

WHO has started a number of programmes for preventing AIDS such as making blood (from blood banks) safe from HIV, ensuring the use of only disposable needies and syringes, free distribution of condoms, controlling drug abuse and promoting regular check-up’s in HIV susceptible populations.




A) MCQs:


1) The human immune system consist of:

(a)Lymphoid organs

(b) Tissue cells

(c) Antibodies

(d) All of these


2) SCID is a:

(a)Deficiency disease

(b) Immune disorder

(c) Allergy

(d) Infection


3) AIDS Infection is caused by:




(d) protozoan



a) False( Auto immuno disorder is an immunity disorder caused by over activity

of immunity system)

b) True

c) True



l) Write full form of ELISA.

li) | NACO stands for which organisation.

lil) What is auto immune disorder?



I) Give a short account of immune disorder.

lI) Write in detail about AIDS and preventive measures for the disease.




CANCER is one of the most dreaded diseases of human beings and is a major cause of death in all over the world. More than a million Indians suffer from cancer and a large number of them die from it annually. Caner is the

uncontrolled divisions of cells that have lost the regulatory mechanism. In our

body, cell growth and differentiation are highly controlled and regulated. In

cancer cells, there is breakdown of these regulatory mechanisms. Normal cells

show a property called contact inhibition by virtue of which contact with other

cells inhibits their uncontrolled growth. Cancer cells appear to have lost this

property. As a result of this, cancerous cells just continue to divide giving rise to

masses of cells called TUMOR.



1. Cancers show uncontrolled mitotic divisions of cells causing unorganised

growth of cells.

2. These ceils grow much more than the normal cells.

3. Due to uncontrolled growth and division of cells, a tumor is generally formed. However, all tumors are not cancerous. No tumor is formed in Leukaemia.

4. These cells have less survival capability.

5. Cancer cells are far less adhesive than normal cells, so these generally wander through the tissues to cause cancerous growth in different parts of body.


6. Cancer cells do not undergo differentiation and do not show contact




On the basis of their original tissue from where they arise, tumors are of THREE



1. CARCINOMAS: These are located in  epithelial tissues and glands, for

 example, breast cancer, stomach cancer, skin cancer, lung cancer etc.


2. SARCOMAS: These are located in connective and muscular tissues, for example, bone cancer, cancer of lymph nodes and muscles.


3. LEUKAEMIA: Also called blood cancer, caused by increased number of WBC's in blood.



tumors are of 2 types:

1. Benign Tumor

2. Malignant Tumor


1.BENIGN TUMOR: Such types of tumors normally remain confined to theiroriginal location and do not spread to other parts of body and cause little damage.


2.MALIGNANT TUMOR §These tumors are a mass of proliferating cells.These cells grow very rapidly, invading and damaging the surrounding normal tissues. Cells from such tumors reach distant sites through blood and start forming a new tumor there. This property in called ae and is the

most feared property of malignant tumors.



1. lonising radiations like X-rays, Gamma rays and particulate radiations from radioactive substances which rupture DNA strands and induce mutations to cause cancer.


2. Excessive exposure to sunlight may stimulate the development of skin cancer.


3. Chemical agents like polycyclic hydrocarbons, caffein, heavy metallic ions

etc. are also carcinogenic.


4. Hormones like testosterone and estrogen are known to cause prostate and breast cancer respectively.


5. Tobacco smoking causes lip, mouth and lung cancer due to presence of carcinogenic agents benzpyrene and N-nitroso-dimethylene.


6. Oncoviruses have viral oncogenes which cause Cervix cancer.



1. Presence of a persistent tumor.

2. Any wound with continuous bleeding.

3. Any wound not healing for long period.

4. Persistent indigestion.

5. Rapid change in appearance, form and growth on some parts of body.

6. Persistent changes in the bowel movements.

7. Persistent hoarseness in voice, or persistent coughing, or persistent

difficulty in swallowing indicate chances of throat cancer.

8. Unexpected loss of weight.

9. Excessive bleeding in the menses.



Cancer detection is based on BIOPSY and HISTOPATHOLOGICAL studies of the tissues, blood and bone marrow.IN BIOPSY a piece of the suspected tissue cut into thin sections is stained and examined under microscope by a pathologist.Techniques like radiography (use of x-rays), CT (computed tomography)

and MRI (magnetic resonance imaging) are very useful to detect cancers of internal organs.

Antibodies against cancer specific antigens are also used for detection of certain cancers.Techniques of molecular biology can be applied to detect genes in individuals

with inherited susceptibility to certain cancers.



Most cancers are treated by surgery, radiotherapy and chemotherapy.In radiotherapy tumor cells are irradiated lethally, taking proper care of the normal tissue surrounding the tumor.In chemotherapy, chemotherapeutic drugs are used to kill cancerous cells.





1. Most of the cancers are treated by:



(c) Chemotherapy

(d)AIl of the above


2. Antiviral proteins are known as:



(c)AH factors



3. Which of the following is correct for benign tumor?

(a)It extends into neighbouring tissues

(b)It grows first slowly, then rapidly

(c)It remains confined to the site of its origin

(d)It is cancerous


4. Which of the following is a form of cancer?




(d)AIl of the above


5. An abnormal rise in the WBC’s count is:



(c) Haemopoiesis




1. Malignant tumor is highly cancerous as it invades surrounding


2. Cancerous cells show property of contact inhibitions.

3. Biopsy is a method of detection of cancer.



1. The agents which cause cancer are called .

2. An outgrown which is developed due to uncontrolled division of cells is known as .



Multiple Choice Questions:

1. (d) All of the above (Cancers can be treated by surgery, radiotherapy and

chemotherapy. )


2. (a) Interferons (Interferons are antiviral proteins released by cells in response to a viral infection.)


3. (c)lt remains confined to the site of its origin (Benign tumor remains confined to the site of origin.)


4. (d) All of the above (All carcinoma, leukaemia and lymphoma are forms of



5. (b) Leukaemia (Leukaemia is an abnormal rise in count of WBC’s.)




True or False:

1. True

2. False: Cancerous cells do not show property of contact inhibitions, they

become pushy to spread.

3. True


1. Carcinogens

2. Tumor


1. Name type of the cancer in which no tumor is formed.

2. Explain what is Metastasis?

3. Write differences between benign and malignant tumor.

4. Write various danger signals of cancer.


1. What are the causes of cancer? Explain different therapies for the treatment of cancer.





The physical and mental dependency on smoking, drugs and alcohol, is

called Addiction.The person who has become dependent upon these chemicals is called an

“Addict”.Addiction is a psychological attachment to certain effects, like euphoria and a temporary feeling of normalcy, of smoking, alcohol and drugs. But with

repeated use of these, the tolerance level of their receptors increases and respond only to higher dose of these chemicals.This finally results in addiction or dependency.


An addict is so dependent on drugs that, he cannot live without Daily Dose of drugs. The amount required to produce the required effects increases with regular use. Addiction has been reported on the rise especially in the adolescents. This is a serious concern because abuse of tobacco, alcohol

or drugs produces many ill-effects of individual's health, his/ner family and

even on the society.The various sources of drugs are:



Tobacco is derived from the dried and cured leaves of young branches of


two species of tobacco plant: Nicotiana tobaccum (a native plant of tropical America) and N. rustica (family Solanaceae).



Tobacco is being used by human beings for more than 400 years. It was first used by the RED INDIANS in America. It spread to European countries in early 17 century. Today it is smoked all over the world. Tobacco is

mainly taken in the form of cigarette or bidies(smoking), chewing and sniffing.



Tobacco is a harmful intoxicant. Tobacco contains a highly poisonous alkaloid called Nicotine. It is so toxic that the amount of nicotine present in one cigarette is proven fatal, if it is injected intravenously into a person.Continuous use of nicotine leads to addiction. Besides nicotine, tobacco

smoke also contains carbon monoxide, N — Nitrosodimethyne,polycyclic hydro-carbons like benzpyrene and tar.



Though tobacco smoking may provide some temporary relief to the strained nerves (a sense of tranquility or peace) but the regular use of tobacco causes number of ill effects on various organs of the body. As

while smoking, only 10% of the smoke is inhaled and the absorption rate of

tobacco smoke is very slow, its ill effects become evident only after prolonged use.



1. It stimulates conduction of nerve impulses.

2. Stimulates adrenal medulla to secrete adrenalin and nor-adrenalin


3. Increased constriction of blood vessels.

4. Increased rate of heart beat, blood pressure and cardiac output.

5. Relaxes the muscles.

6. High concentration of tobacco paralyses neurons.

7. Regular use causes addiction.


TOBACCO SMOKING AND DISEASES:Tobacco smoking is associated with several diseases:


1. Cancer: Benzpyrene of tobacco is carcinogenic in nature. About 95% of

victims of lung cancers are associated with smoking. Reverse smoking causes Oral cancer. Lip cancer is also associated with smoking. About 33% of all cancers are caused by tobacco. About 50% of all cancers

among men and 25% among women are tobacco related. It is more common in person smoking cigarettes than those smoking cigar or pipe

because cigarette smokers inhale smoke with polycyclic hydrocarbons.Tobacco chewing generally causes mouth cancer.


2. Tobacco smoke causes irritation and inflammation of mucosa of throat

and bronchi which causes coughing and bronchitis. The chemicals in cigarette smoke in-activates cilia of respiratory tract so the phlegm accumulates.


3. Nicotine of tobacco causes increased secretion of adrenalin and non-adrenalin which increases blood pressure and rate of heart beat which may cause cardiovascular diseases.


4. Emphysema: tobacco smoke is known to cause inflammation of lung alveoli which decreases surface area for gaseous exchange and

causes emphysema.


5. It causes increased secretion of gastric juices which causes gastric and duodenal ulcers.


6. Smoking is known to aggravate pulmonary tuberculosis.


7. Carbon monoxide of tobacco smoke rapidly binds haemoglobin of RBC and forms carboxyl-haemogiobin and causes CO-poisoning which

decreases O2 — carrying capacity of haemoglobin of RBC’s which causes hypoxia in the body tissues.


8. Nicotine of tobacco smoke retards the foetal growth in the mother's womb.


9. Smokers have a greater tendency of byssinosis, a lung disease, caused

by prolonged inhalation of textile dust.


10. Smoking and lifespan: There are many evidences which show that smoking shortens lifespan.Smoking only one cigarette shortens your lifespan by 11 minutes,while smoking a carton of cigarettes takes about 1.5 days off your lifespan.



May 31* is observed as “NO TOBACCO DAY’, all over the world. It is aimed to counter the alarming health; economic and human costs being extracted by the killer weed.




1. Tobacco smoking has been prohibited in hospitals, dispensaries and other health care establishments, educational institutions, conference rooms, domestic air fights, air-conditioned chair cars, sleeper coaches and buses etc.

2. Smoking has also been prohibited in public places all over in India.

3. Ithas been mandatory to print a warning — Ee (ES On chewing tobacco products.

4. Direct advertisements relating to tobacco or tobacco related products are prohibited on Doordarshan and All India Radio.

5. Anti-Tobacco Act passed on May 1, 2004 states:


Ban on sale of tobacco products within 100 meters of educational institutions from Dec 1, 2004.


Mandatory depiction pf statutory warning including pictorial symbols on packets of tobacco products.


6. By 2030, tobacco is expected to be single biggest cause of death worldwide accounting for 10 million deaths per year.



A)Multiple Choice Questions:


1. Which of the following is associated with smoking?


(b)Lung Cancer


(d)AIl of the above


2. World No Tobacco Day is celebrated on:

(a)May 31st

(b)June 6th

(c)April 22nd

(d)October 2nd


3. The component in tobacco that stimulates secretion adrenalin and non-adrenalin is:

(a)Tannic acid





4. Nicotine in tobacco is synthesised in:






5. Tobacco smoking causes:

(a)Lung cancer

(b)Coronary disease

(c) Infertility in males

(d)AIl of these


B)True or False:

1. Benzpyrene in tobacco is carcinogenic in nature.

2. Tobacco smoking causes inflammation of lung alveoli and decreases surface area for gaseous exchange and causes Emphysema.

3. Chewing of tobacco does not cause mouth cancer.


C) Fill in the blanks:

1. Tobacco contains highly poisonous alkaloid called .

2. Tobacco smoke causes irritation and inflammation of mucosa of the throat and bronchi which causes and .



A) Multiple Choice Questions:

1. (d) All of the above (Bronchitis, Lung cancer and Emphysema all are associated with smoking).


2. (a) May 31 (World No Tobacco Day is celebrated on May 31).


3. (b) Nicotine (stimulates secretion of adrenalin and non-adrenalin).


4. (c) Nicotine (is synthesised in leaves of tobacco plant).


5. (d) All of the above (Lung cancer, coronary diseases and infertility in

males is caused by tobacco smoking).


B)True or False:

1. True

2. True

4. False: Chewing of tobacco causes mouth cancer.


C)Fill in the blanks:

1. Nicotine

2. Coughing and Bronchitis


1. Name two toxic chemicals present in tobacco.

2. What is meant by addiction?

3. Name two respiratory diseases associated with smoking.


1. Name and explain various diseases associated with tobacco smoking.





The word Alcohol refers to Ethyl Alcohol (C2HsOH). Alcohol is manufactured by fermentation of sugar. Alcohol is quickly absorbed in the stomach and upper part of the intestine and transferred to the blood. Firstly it affects the cerebrum part of the brain. Many people think that alcohol is  stimulant. But actually, alcohol act as sedative, analgesic and anesthetic.


When drinking of excessive alcohol is done that impairs one’s physiological, physical and psychological function. It constitutes alcohol addiction.


Addiction means psychological attachment to certain effects such as euphoria and temporary feeling of well-being with alcohol and drugs.



Five stages are recognized:


i) Experimental use: - Taking alcohol or drug under group or peer pressure.


ll) | Recreation use: - use of alcoholic substances out of wrong notion that is gives pleasure or euphoria.


Ill) Situational use: - Intake of alcohol or drug more than few time but only in the company of other.


IV) Compulsive use: - With regular use the tolerance level of receptor increases.

V) Dependence: - After an interval of regular use a person become dependent and cannot do anything without alcohol.



1. Deficiency of nutrients: - Deficiency of nutrients such as minerals, proteins,

vitamins are found in alcoholic.


2. Effect on immunity:- Chronic alcoholic neglect their health and soon body loses its resistance against infections.


3. Effect on brain:- Alcohol is depressant to brain.


4. Effect on cardiovascular system: - Drinking leads to hypertension and

increased size of heart. Heart valves became inefficient.


5. Effects on liver: - Liver size increases due to reduction in gluconeogenesis

(formation of glucose from glycogen) and this leads to liver cirrhosis.


6. Mood disorder: - Alcoholic often develops various types of mood disorder such as sadness, anxiety.


7. Impotency and infertility: - Alcoholism produces impotency and infertility Alcohol always delays maturity in adolescent.


8. Cancer risk: - Alcohol increases the risk of carcinoma by ten times.


9. Life span: - Continued intakes of alcohol shorten the average life span by 10-

15 year.


10. Social problems: - These include absence from work, unemployment,marital tension, child abuse, financial difficulties etc.


WITHDRAWAL SYMPTOMS OF ALCOHAL:-When an alcohol addict tries to stop regular dose of alcohol then these following symptoms appears:-

1. Anxiety.

2. Nervousness.

3. Depressed mood.

4. Restlessness.

5. Insomnia (sleeplessness).

6. Impaired concentration.

7. Excessive sweating, nausea, vomiting.



Prevention is better than cure is also true here.This habit generally picked up during young age so following measures

should be taken in adolescent period:-

1. Avoid undue peer pressure.

2. Education and counseling are very important to face problems.

3. Seeking help from parents and peers if there is any problem.

4. Parents and teachers should always careful to look for and identify danger


5. Take professional and medical help if it is required.



all Multiple cheice questions:.


1. Cirrhosis of liver caused by:

a) Cocaine

b) LSD




2. In the liver, alcohol is converted into toxic substance:

a) Formic acid

b) Acetaldehyde

c) Nicotine

d) Urea


3. In drunk person, parts of brain to affected first in:

a) Cerebellum

b) Pons varolli

c) Medulla

d) Cerebrum


4. In alcoholic liver damaged as it:

a) Accumulates excess of fats

b) Store glycogen

c) Secrete bile

d) Detoxify alcohol


5. Effect of alcohol in body. Choose the wrong one

a) Alcohol increases the size of liver

b) Alcohol increases chance of cancer

c) Alcohol improves your immunity

d) Alcohol create impotency


1. Addiction is psychological attachment to certain affects.

2. Alcoholism increases the life span.

3. Alcohol addiction causes impotency.


1. The word alcohol refers to ...........alcohol.

2. Anxiety, restlessness, insomnia are withdrawal symptoms of



(a) Multiple choice questions:


1. (c) Alcohol causes liver damage called cirrhosis.

2. (b) Acetaldehyde-:- it is a toxic for cell.

3. (c) Cerebrum:-it is a part of brain which is affected first.

4. (a) Excess of fats accumulate which cause fatty liver condition.

5. (c) Alcohol deteriorate the health does not improve it.


(b) True/ False:

1. True

2. False: Alcoholism decreases the life span by 10 to 15 years.

3. True


(c) Fill-Ups:

1. C2HsOH (ethyl alcohol)

2. Alcohol



1. List the four harmful effects of alcohol?

2. Why is that once a person start taking alcohol it is difficult to get rid of this


3. Do you think that friend can influence one to take alcohol?



1. Explain the preventive measure to control alcohol addiction?




Drugs are technically medicines or substances used internally or externally for the

purpose of diagnosis, prevention or cure of diseases.Drugs are normally used as medicines to help the patients but when drugs are

taken for purpose other than their normal clinical use in an amount that impairs one’s physical, physiological and psychological functions it constitutes DRUG ABUSE.A person who takes a drug for non-medical use is called DRUG ABUSER and drugs are called ADDICTIVE DRUGS.


Based on the effect on the body, drugs are mainly of two types:-




1.PSYCHOTROPIC DRUGS: These are mood altering drugs which selectively affect behavior, perception and mental activity of a person. These include Sedatives or antidepressents, Tranquillisers or antidepressents with soothing or calming effects, Opioids or narcotics and Stimulants or exciters.

Most common among these are:


These drugs derived from OPIUM plant. These drugs relieve pains, acting on Central Nervous System. Opioids bind to specific opioid receptors present in our central nervous system and gastrointestinal tracts. They are also called pain killer.

Opium is latex obtained from unripe fruits of poppy plant (Papaver somniferum). It

is reddish brown in color having bitter taste. It is eaten or smoked.Opium has many derivatives as following:


1. Morphine: -It is active alkaloid of opium. It is strong analgesic. It has sedative

and calming effect. It causes addiction. It is used in patient who has undergone surgery.


2. Heroin: -it is semi-synthetic crystalline powdery substance obtained by acetylation of morphine. Chemically it is known as Di Acetyl Morphine having formula, Ci7Hi7(OC2H30)-ON. It is highly addictive and dangerous. Heroin is taken, orally, inhaled or injected. Heroin is depressant and slow down body functions.


3. Smack:-It is crude by- product of heroin synthesis and is commonly called “brown

sugar’. Being cheap, it is considered “poor man’s heroin”. Smack is stronger analgesic than morphine.


B) RG | is natural coca alkaloid. Obtained from leaves of coca.A South American plant, growing on the foot hill. Cocaine is commonly called coke or crack. It is bitter, white crystalline powder. Cocaine has vaso constriction properties and therefore is a good anesthetic. It is powerful CNS stimulant.Excessive dosage of cocaine causes Hallucination.


C) RT hey are synthetic drugs. They are commonly called PEP pills, Anti-Sleep drugs or Superman Drugs. They are CNS stimulant.

They bring about increased activity and alertness real.



Psychedelic drugs change one’s behavior, thoughts, feelings and perceptions without actual sensory stimulus.Hallucinations are sensory experiences that appear real but are created byyour mind. They can affect all five of your senses. For example, you might

hear a voice that no one else in the room can hear or see an image that isn't.


Common HALLUCINIGENS are as under:-



It is most powerful psychedelic drug. It is in crystalline form obtained from

ERGOT, an extract got from fruiting body of fungus Claviceps purpurea.It is always smoked. LSD cause horrible dream emotional outburst,hallucination.



Hallucinogenic chemicals obtained from leaves, resin and inflorescence of

hemp plants, cannabis sativa are called cannabinoids, and these are generally

four types:


a) BHANG :- Itis fresh/dried leaves of both male and female plant of Cannabis sativa.


b) GANJA: - It is dried unfertilized female inflorescence.


c) CHARAS/HASHISH: - It is dried resinous extract from flowering top of plant.


d) MARIJUANA: - This is obtained from dried flowers and top leaves of female



lll) DATURA & BELLADONA:- Seeds of Daturas tramonium and aerial parts of Atropa belladonna are misused for their hallucinogenic properties due to

presence of anticholinergic alkaloids.




i) Multiple choice questions: -


1. Opium is obtained from

a) Theasinensis

b) Coffeaarebica

c) Oryza sativa

d) Papaversomnefera


2. Marijuana, ganja and LSD are

a) Narcotics

b) Hallucinogens

c) Stimulants

d) Medicine.


3. LSD is obtained from:

a) Cannabis

b) Claviceps

c) Fusarium

d) Nostoc


4. Hemp yields:

a) Bhang

b) Charas

c) Ganja

d) All of above


5. Cocaine is derived from

a) Eythroxylon coca

b) Coffeaorbica

c) Theasinesis

d) Connabis sativa


(ii) True/ False

1. Cocaine is most powerful stimulant.

2. Nicotine is narcotic.

3. LSD is hallucinogen.


(iii) Fill in the blanks

1 Morphine is obtained from ................. Plant.

2 Marijuana obtained from dried flower of .................. plant.



(a) Multiple choice questions:

1 (d) Papaver somniferum a plant which produce a latex called opium.


2 (b) Hallucinogens this chemical produces effect when a person consumes these drugs.


3 (b) Claviceps is an ergot fungus from which LSD obtained.


4(d) All products like bhang, charas, ganja are obtained from hemp plant.


5 (a) Erythroxylum coca a native plant of South America produces cocaine.


(b) True/ False:

1. True

2. False; Opioids are narcotics. Nicotine is habit forming constituent of


3. True


(c) Fill-Ups:

1. Opium Poppy Plant

2. Female Hemp Plant



1. Name the plant source of drug popularly called heroin. How does it affect body?

2. What is cocaine? What is the adverse effect?

3. what are cannabinoids? Name different types of c cannabinoids?



1. Explain opioids and the derivatives how they act on the body of drug







ADDICTION is a psychological attachment to certain effects . such as euphoria

and a temporary feeling of well-being associated with drugs and alcohol.

With repeated use of drugs, the tolerance level of the receptors present in our body

increases and consequently the receptors respond only to higher doses of drugs or

alcohol leading to greater intake and addiction.DEPENDENCE is the tendency of the body to manifest a characteristic and

unpleasant withdrawal syndrome if regular dose of drugs/alcohol is abruptly

discontinued. Withdrawal syndrome is characterized by anxiety, shakiness, nausea

and sweating.



Adolescence means both ‘a period’ and ‘a process’ during which a child becomes

mature in terms of his/her attitudes and beliefs for effective participation in society.12-18 years of age may be thought of as adolescence period.


Adolescence is accompanied by several biological and behavioral changes.Curiosity, need for adventure and excitement, and experimentation, constitute common causes, which motivate youngsters towards drug and alcohol use.




Reckless behavior, vandalism and violence.


Excessive doses of drugs may lead to coma and death due to respiratory failure, heart failure or cerebral hemorrhage.


Those who take drugs intravenously can get infected with AIDS, hepatitis B.


The chronic use of drugs and alcohol damages nervous system and cause liver cirrhosis.


The use of drugs and alcohol during pregnancy is also known to adversely affect the fetus.


Use of anabolic steroids in females can cause masculinization, increased aggressiveness, mood swings, depression, abnormal menstrual cycles.excessive hair growth on the face and body. enlargement of clitoris.deepening of voice.


In males anabolic steroids can cause acne, increased aggressiveness, mood swings, depression, reduction of size of the testicles, decreased sperm production, potential for kidney and liver dysfunction, breast enlargement,premature baldness, enlargement of the prostate gland.



The measures useful for prevention and control of alcohol and drugs abuse

among adolescents:


Avoid undue peer pressure on children.


Children should be educated and counseled to bear problems and stress in life.


The child should seek help from parents and elders.


Affected individuals should seek medical help of qualified psychologists,psychiatrists, and deaddiction and rehabilitation programs.






1. With repeated use of drugs, the tolerance level of the receptors present in our body:

a. Increases

b. Remains same

c. Decreases

d. None of the above


2. Excessive doses of drugs may lead to coma and death due to:

a. Respiratory failure

b. Heart failure

c. Cerebral hemorrhage

d. All of the above


3. Which factor is responsible for liver cirrhosis?

a. Sugar

b. Alcoholism

c. Fats and oil

d. Vitamins


4. Withdrawal syndrome is characterized by:

a. Shakiness

b. Sweating

c. Anxiety

d. All of the above


5. Drug addiction is psychological attachment to certain effects such as:

a. Euphoria

b. Temporary feeling

c. Both A and B

d. None of the above



1. Excessive use of alcohol causes

2. Persons taking drugs intravenously can be infected with



1. The use of drugs and alcohol during pregnancy affects the fetus.

2. Avoid undue peer pressure on children.

3. Withdrawal syndrome develops if regular dose of drugs is continued.







1. a. increases- With repeated use of drugs, the tolerance level of drugs increases

2. d. All of the above- Excessive doses of drugs leads to failure of all the vital


3. b. Alcoholism- Excessive intake of alcohol causes fatty liver which is called liver cirrhosis.

4. d. All of the above- Withdrawal syndrome is characterized by anxiety,sweating and shakiness.

5. c. Both A and B- Drug addiction causes euphoria (feeling of extreme happiness) and temporary feeling.



1. Liver cirrhosis- Excessive use of alcohol causes fatty liver which is called

liver cirrhosis.

2. AIDS & Hepatitis B- Sharing of injection, needles between two individuals

can cause AIDS and Hepatitis B.



1. True

2. True

3. False- Withdrawal syndrome develops if regular dose of drugs is discontinued.



1. What is withdrawal syndrome?

2. What are the side effects of anabolic steroids in males?



1. What motivates the youngsters to take alcohol or drugs and how can this is avoided?





Dear students we have completed the chapter 08- Human Health & Disease very thoroughly in the Daily Dose assignments from 83 to 99.

Now Let Us Solve NCERT Questions of this chapter.


1. What are the various public health measures, which you would suggest as safeguard against infectious diseases?

Answer:Public health measures which should be taken to safeguard against infectious

diseases are:


(i) Maintenance of personal and public hygiene: It is one of the most important methods for prevention of various infectious diseases. This measure consists of maintaining a hygienic body, taking of healthy and nutritious food,drinking clean water, etc. In public hygiene there is proper disposal of garbage, excreta, periodic cleaning of society, and cleaning of water reservoirs.


(ii) isolation: To prevent the spread of air-borne infectious diseases like

pneumonia, chicken pox, tuberculosis, etc., it is an essential measure to keep the

infected person in isolation with others to reduce the chances of spreading these

infectious diseases.


(iii) Vaccination: Vaccination is the protection of the body from communicable

diseases by injecting some agent that makes copy of the microbe inside the body. It

helps in providing passive immunity to the body. Several vaccines are available

against many diseases such as tetanus, polio, measles, mumps, etc.


(iv) Vector Eradication: Various diseases such as malaria, filariasis, dengue, and

chikungunya spread through vectors. Thus, these diseases can be prevented by

providing a clean environment and by the prevention of breeding of mosquitoes. This

can be achieved by not allowing water to stagnate around public areas. Also,

measures like periodic cleaning of coolers, use of mosquito nets and spreading of

insecticides in drains, ponds, etc. can be undertaken to ensure a healthy

environment. Introducing fish such as Gambusia in ponds also controls the breeding

of mosquito larvae in still water against diseases.

2. In which way has the study of biology helped us to control infectious


Answer:Various advancements that have occurred in the field of biology have helped us gain a better understanding to fight against various infectious diseases.


Biology has developed as we have come to know about the life cycle of various parasites, pathogens, and vectors along with the modes of transmission of various diseases and the measures for controlling them.


Vaccination programmes against several infectious diseases such as small pox,

chicken pox, tuberculosis, etc. have helps us to eradicate these diseases.


Biotechnology has helped in the preparation of developed and safe drugs and vaccines.


Antibiotics have also played a major role in the treatment of various infectious



3. How does the transmission of each of the following diseases take place?

(a) Amoebiasis (b) Malaria (c) Ascariasis (d) Pneumonia

Answer:(a) Amoebiasis: It is a vector transmitted disease that spreads by the means of contaminated food and water. The vector involved in the transmission of this disease

is the housefly. Its mode of transmission is Entamoeba histolytica.


(b) Malaria: It is a vector transmitted disease that spreads by the biting of the

female Anopheles mosquito. Its mode of transmission is Plasmodium protozoan.


(c) Ascariasis: It spreads through contaminated food and water. Its mode of

transmission is Ascaris lumbricoides.


(d) Pneumonia: It spreads by the sputum of a diseased person. Its mode of

transmission is Streptococcus pneumonia.


4. What measure would you take to prevent water-borne diseases?

Answer:Water-borne diseases such as cholera, typhoid, hepatitis B, etc. spread by drinking

contaminated water.


These water-borme diseases can be prevented by proper disposal of garbage,excreta, regular cleaning.


Spraying insecticide in community water reservoirs, boiling drinking water, etc.


5. Discuss with your teacher, what does ‘a suitable gene’ means, in the context of DNA vaccines.

Answer:A suitable gene of specific DNA segment when inserted in the body of host to

produce specific type of protein which gives passive immunity to the organism and

helps to fight with foreign organism.


6. Name the primary and secondary lymphoid organs.

Answer:(i) Primary lymphoid organs include the Thymus and Bone Marrow.

(ii) Secondary lymphoid organs are the Spleen, lymph nodes, Tonsils, Peyer's

patches of small intestine, and Appendix.


7. The following are some well-known abbreviations, which have been used in this chapter. Expand each one to its full form:

(a)MALT (b)CMI (c)AIDS (d)NACO = (e) HIV


(a) MALT- Mucosa-Associated Lymphoid Tissue

(b) CMI- Cell-Mediated Immunity

(c) AIDS- Acquired Immuno Deficiency Syndrome

(d) NACO- National AIDS Control Organization

(e) HIV- Human Immune Deficiency virus


8. Differentiate the following and give examples of each:

(a) Innate and acquired immunity (b) Active and passive immunity






10. What are the various routes by which transmission of human immuno-deficiency virus takes place?

Answer:AIDS (Acquired Immuno Deficiency Syndrome) is caused by the Human immunodeficiency virus (HIV).This is transmitted by following modes -


(a) Unprotected sexual contact with a diseased person.

(b) Transfusion of blood to a healthy from a diseased person.

(c) Sharing infected needles or syringes.

(d) Infected mother to a child through the placental connection.


11. What is the mechanism by which the AiDS virus causes deficiency of

immune system of the infected person?

Answer:AIDS (Acquired Immuno Deficiency Syndrome) is caused by the Human immunodeficiency virus (HIV) via sexual or blood to blood contact.


After entering the human body, the HIV virus attacks and enters into the macrophages. Inside the macrophages, the RNA of the virus replicates with the help of enzyme reverse transcriptase and gives rise to viral DNA copy.


Then, this viral DNA incorporates into the host DNA and directs the synthesis of

virus particles. - At the same time, HIV enters helper T- lymphocytes. It replicates

and produces viral progeny.


These newly formed progeny viruses get released into the blood, attacking other

healthy helper T-lymphocytes in the body.


As aresult, the number of T-lymphocytes in the body of an infected person decreases in number, which causes decrease in immunity of person.


12. How is a cancerous cell different from a normal cell?



13. Explain what is meant by metastasis?

Answer:The property of metastasis is performed by malignant tumors. These malignant cells move through different part of body by a pathological process. These cells divide uncontrollably, forming a mass of cells called tumor. From the tumor, some cells get shed off and enter into the blood stream. From the blood stream, these cells reach distant parts of the body and therefore, start the formation of new tumors by dividing actively.


14. List the harmful effects caused by alcohol/drug abuse.



(i) Alcohol generates more energy mosily in the form of heat, but at the same time,

it dilates the blood vessels. Consequently the ‘heat generated is rapidly lost. Due

to constant dilation, the arterial walls soon become brittle & rigid. Such a change in

the property of blood vessels & deposition of alcoholic fat affect the working of heart.


(ii) Alcoholism leads to gastric ulcers & gastritis.


(iii) In chronic alcoholism, the axon of the nerve inflames thus causing neuritis.


(iv) Permanent damage to liver cells occur due to deposition of fats.The liver dries up & harden (CIRRHOSIS).



(i) Excessive doses of drugs may lead to coma & death due to respiratory failure,heart failure & cerebral hemorrhage.


(ii) Lack of interest in personal hygiene, withdrawal, isolation, depression, fatigue

aggressive & rebellious behavior etc.


(iii) Acquire serious infections like AIDS & HEPATITIS B, who take drugs intravenously.


(iv)The adverse effects of drugs are manifested in the form of reckless behaviour,

vandalism & violence.


15. Do you think that friends can influence one to take alcohol/drugs? If yes, how may one protect himself/herself from such an influence?

Answer:Yes, friends can influence one to take drugs. Following measures can be taken:

(i) Avoiding undue peer pressure.

(ii)Not taking undue pressure of failures beyond its threshold.

(iii) Getting counseling from some counselor.

(iv) Seeking help from parents and peers.

(v) Seeking medical help.


16. Why is that once a person starts taking alcohol or drugs, it is difficult to get rid of this habit? Discuss it with your teacher.

Answer:Psychological & physiological dependence of an individual to the intake of certain kinds of drugs and alcohol is called addiction. Once a person starts taking alcohol & drugs, it is very difficult to get rid this habit because addiction drive people to take them even when these are not needed or even when their use becomes self-

destructive. With repeated use of drugs, the tolerance level of the receptors present

in the body increases, consequently, the receptors responds only to higher doses of

drugs or alcohol leading to greater intake & addiction. Thus, the addiction potential of

drugs & alcohol, pull the user into a vicious circle leading to their regular use (abuse)

from which he/she may not able to get out.


17. In your view what motivates youngsters to take to alcohol or drugs and how can this be avoided?

Answer:Human have probably been using mind — affecting drugs since time immemorial. The

root cause of addiction of man to drugs, smoking and drinking has been due to his

inability to make mental adjustments with stresses and strains, drudgery and

extreme misery in daily life. As a temporary measure, to combat these adverse situations and to have a certain degree of mental relaxation, humans have been making an extensive use of stimulants, depressants and hallucinogens. Stimulants generally speed up body process, and depressants slow them. Hallucinogens can alter a person's thoughts, feelings. and perception.In preventing drug abuse, the role of parents could be:

1. Communicate openly with the children,

2. Listen to their problems patiently and teach them how to handle the problems.

3. Take interest in children’s activities and their friends circle.

4. Set an example for children by not taking drugs or alcohol.

5. Keep track of prescribed drugs in home.

6. Learn as much as possible about drugs.





Dear students we have discussed the whole chapter no. 08 “HUMAN HEALTH AND DISEASES’ and its NCERT questions in Daily Dose Assignments from 83 to 100.Now let us revise the common terms and important concepts:



Non-specific defenses are the body's first line of defense against diseases. They are

not directed against a particular pathogen. Non-specific defenses guard against all

infections, regardless of their cause. It is also called as innate immunity. Plants and

many lower animals rely only on innate immunity and do not possess the second

category of specific defense mechanisms. Nonspecific defense mechanisms work

against a wide variety of invaders. Innate immunity consists of various types of

barriers that prevent entry of pathogens into the body.



Specific defense mechanism is the ability of the body to develop immunity against

specific pathogens, toxins, or foreign things. This is possible by a special immune

system that produces antibodies and/or activated lymphocytes that attack and

destroy specific invading organisms or toxins.



Antibodies are immune system-related proteins called immunoglobulins. Each

antibody consists of four polypeptides— two heavy chains and two light chains joined

to form a "Y" shaped molecule.



Antigen-antibody interaction, or antigen-antibody reaction, is a specific chemical

interaction between antibodies produced by B cells of the white blood cells and antigens during immune reaction. The antigens and antibodies combine by a process called aggiutination. It is the fundamental reaction in the body by which the body is protected from complex foreign molecules, such as pathogens and their chemical toxins. In the blood, the antigens are specifically and with high affinity bound by antibodies to form an antigen-antibody complex. The immune complex is then transported to cellular systems where it can be destroyed or deactivated.



Vaccination is the process of introduction of vaccines into the body to produce

antibodies against the antigens to neutralize the effect of pathogens during actual

infection.Vaccines are the dead or weakened pathogens introduced into the body.The dead or weakened pathogen leads to the production of antibodies which neutralizes the pathogenic agents during actual infection with the same pathogen.

Immunization is the process where performed antibodies against the toxin are introduced into the body.

Example- performed antibody injection against snake venom.Using recombinant DNA technology antigenic polypeptides of pathogens in bacteria or yeast.

Example- hepatitis B vaccine produced from yeast.



The organs where origin and/or maturation and proliferation of lymphocytes occur

are called lymphoid organs.

Lymphoid organs are of two types-

1. Primary lymphoid organs

2. Secondary lymphoid organs.


The primary lymphoid organs are bone marrow and thymus where immature lymphocytes differentiate into antigen-sensitive lymphocytes.The bone marrow is the main lymphoid organ where all blood cells including lymphocytes are produced.


The thymus is a lobed organ located near the heart and beneath the breastbone.Spleen, tonsil, lymph node, Peyer’s patches of small intestine and appendix are secondary lymphoid organs where proliferation of lymphocytes take place.The secondary lymphoid organs provide the sites for interaction of lymphocytes with the antigen, which then proliferate to become effector cells.

The spleen is a large bean shaped organ mainly contains lymphocytes and

phagocytes which acts as a filter of the blood by trapping blood-bornemicroorganisms and has a large reservoir of erythrocytes.

The lymph nodes are small solid structures located at different points along the

lymphatic system.Lymph nodes serve to trap the antigens and these antigens trapped are responsible for the activation of lymphocytes and cause the immune response.

Lymphoid tissue is located within the lining of the respiratory, digestive and urogenital tracts.

Lymphoid tissues are also called mucosalassociated lymphoid tissue (MALT) which constitutes about 50 per cent ofthe lymphoid tissue in human body.


7. DISORDERS OF IMMUNITY: Some of the common disorders caused by a poor immune system include:

Allergic diseases — These are the diseases which have symptoms which include

hay fever, sinus disease, asthma, hives, dermatitis and eczema.


Autoimmune diseases — These include multiple sclerosis, autoimmune thyroid disease, type 1 diabetes, systemic lupus erythematosus, rheumatoid arthritis and systemic vasculitis.


There are immunodeficiencies, which are inherited from a parent to the child. These

conditions include primary immunodeficiency diseases such as x-linked severe

combined immunodeficiency (SCID), complement deficiencies, common variable

immunodeficiency (CVID), etc


8. CANCER:Cancer is the uncontrolled cell division leading to the formation of a mass of cells called as a tumor.

Contact inhibition is the property of normal cells by virtue of which contact with other cells inhibits their uncontrolled growth.Cancer cells lost the property of contact inhibition and because of this, cancerous cells continue to divide giving rise to masses of cells called tumors.

Tumors are of two types: benign and malignant.


Benign tumors normally remain confined to their original location and do not spread

to other parts of the body.The malignant tumors are a mass of proliferating cells called neoplastic or tumor cells.Malignant tumors grow very rapidly and invade and ultimately damage surrounding tissues.

The property by which cancer cells moves to distant places from their origin by blood and invade the normal cells and make them cancerous is called as metastasis



Addiction is a psychological attachment to certain effects -such as euphoria and a temporary feeling of well-being — associated with drugs and alcohol.


10. ALCOHOL ADDICTION A chronic disease characterized by uncontrolled drinking and preoccupation with alcohol.Alcoholism is the inability to control drinking due to both a physical and emotional dependence on alcohol.

Symptoms include repeated alcohol consumption despite related legal and health issues. Those with alcoholism may begin each day with a drink, feel guilty about their drinking and have the desire to cut down on the amount of drinking.


11. DRUGS:The drugs which are commonly abused are opioids, cannabinoids and coca



OPOIDS-Opioids are the drugs which bind to specific opioid receptors present in our central nervous system and gastrointestinal tract.


Heroin commonly called smack is chemically diacetylmorphine which is a white,odourless, bitter crystalline compound and is obtained by acetylation of morphine extracted from the latex of poppy plant Papaver somniferum. Heroin is a

depressant and slows down body functions.


CANNABINOIDS:Cannabinoids interact with cannabinoid receptors present principally in the brain.Natural cannabinoids are obtained from the inflorescences of the plant Cannabis



The flower tops, leaves and the resin of cannabis plant are used in various

combinations to produce marijuana, hashish, charas and ganja effects on cardiovascular system of the body.


COCA ALKALOID:Coca alkaloid or cocaine is obtained from coca plant Erythroxylum coca.

Coca alkaloid interferes with the transport of the neuro-transmitterdopamine.Cocaine, commonly called as coke or crack .It has a potent stimulating action oncentral nervous system, producing a sense of euphoriaand increased energy.Excessive dosage of cocainecauses hallucinations.


TOBACCO: Tobacco conatins nicotine, an alkaloid.Nicotine stimulates adrenal gland to release adrenaline and nor-adrenaline into

blood circulation, both of which raise blood pressure and increase heart rate.Smoking of tobacco is associated with increased incidence of cancers of lung,urinary bladder, throat, oral cavity, bronchitis, emphysema, coronary heart disease, gastric ulcer etc.


12. DRUG ADDICTION:With repeated use of drugs, the tolerance level of the receptors present in our body increases and consequently the receptors respond only to higher doses of drugs or alcohol leading to greater intake and addiction.Dependence is the tendency of the body to manifest a characteristic and unpleasant withdrawal syndrome if regular dose of drugs/alcohol is abruptly discontinued.

Withdrawal syndrome is characterised by anxiety, shakiness, nausea and sweating.




1. Name the diagnostic test which confirms typhoid.

Ans. V\idal test


2. Name the two major groups of cells required to attain specific immunity.

Ans. B-lymphocytes and T-lymphocytes.


3. You have heard of many incidences of Chickengunya in our country. Name the vector of the disease.

Ans. Aedes mosquitoes.


4. Breast fed babies are more immune to diseases than the bottle-fed babies.Why?

Ans. The mother’s milk consists of antibodies (lg A) such antibodies are not available to bottle fed babies.


5. Name the pathogen which causes malignant malaria.

Ans. Plasmodium falciparum.


6. Which microorganism is used to produce hepatitis B Vaccine?

Ans. Yeast.


7. What is the reason of shivering in malarial patient?

Ans. After sparozoite infection, wnen RBC ruptures, a toxic substance haemozoin is

released which cause chilling and high fever.


8. When is a tumour refered to as malignant?

Ans. A tumour is said to be malignant when grows rapidly, invade & damage the

surrounding normal tissues.



9. Why does an AIDS patient suffer from many infections?

Ans. Because in AIDS patient, immune system greatly weakens & cannot fight against any infection.


10. Name two curable sexually transmitted diseases?

Ans. Gonorhoea & Syphilli


11. Name the type of cells that produce antibodies?

Ans. B — lymphocytes.


12. Give the scientific name of causative germ of elephantiasis?

Ans. WuchereriaBancrofti.


13. Name the fish that help in eradication of mosquito larvae.

Ans. Gambusia



1. Where are B-cells and T-cells formed? How do they differ from each other?

Ans. B-cells and T-cells are formed in bone marrow. B-cells produce antibodies but E-cells do not produce antibodies but help B-cells to produce them.


2. Given below are the pathogens and the diseases caused by them. Which out of these pairs is not correct matching pair and why?

(a) Wuchereria- Filariasis

(b) Microsporum- Ringworm

(c) Salmonella - Common Cold

(d) Plasmodium — Malaria

Ans. Salmonella : Common cold is not a matching pair.


3. What would happen to the immune system, if thymus gland is removed from the body of a person?

Ans. T-lymphocytes are developed and matured in thymus gland, Immune system will become weak on removal of thymus gland.


4. Lymph nodes are secondary lymphoid orgAns. Describe the role of lymph nodes in our immune response.

Ans. Lymph nodes provide the sites for interaction of lymphocytes with the antigen.

When the microorganisms enter the lymph nodes, lymphocytes present there are

activated and cause the immune response.


5. What is the role of histamine in inflammatory response? Name few drugs

which reduce the symptoms of allergy.

Ans. Histamine acts as allergy-mediator which cause blood vessels to dilate. It is

released by mast cells. Antihistamine steroids and adrenaline quickly reduce the

symptoms of allergy.


6. What do you mean withdrawal Symptoms? What are its characteristics?

Ans. Withdrawal symptoms refers to the characteristic unpleasant symptoms by

body of a drug addict if regular dose of drug is abruptly discontinued. These include

anxiety, shakiness, sweating, restlessness, depression, muscular cramps etc.


7. Differentiate between two different types of tumours?



8. Differentiate between active & passive immunity?


9. Enumerate the two properties of cancer cells that distinguish them from

normal cell.

Ans. i) uncontrolled proliferation of cells without any differentiation

ii) Ability of these cells to invade other tissues called metastasis.


10. What are allergens? How do they cause inflammatory response inside human body?

Ans. The substance which causes the hypersensitive reaction of the immune system

is called an allergeneg. dust, pollen grains etc. These allergens are actually weak

antigens. First exposure to allergen does not cause allergy but consequent

exposure, allergen combines with Ig E on mast cell. That causes cells to burst &

release Histamines which cause inflammatory response.


11. What are autoimmune diseases? Give two examples?

Ans. Immunity is based on ability to differentiate foreign organism from self cells.Sometimes immune system may go off the track & turns against self antigen and

elicit immunity. Such conditions are called auto — immune diseases eg. Rneumatoid

arthritis, Myasthenia gravis.


12. What are Cannabinoids? From which plant Cannabinoids are obtained?Which part of the body is affected by consuming these substances?

Ans. Cannabinoids are a group of chemicals which interact with Cannabinoid

receptors present


Principally in the brain Cannabinoids are obtained from the inflorescences of the

plant Cannabis sativa.


The substances affect the cardiovascular system adversely


13. In the figure, structure of an antibody molecule is shown. Observe it and Give the answer of the following questions.

(i) Label the parts A, B and C.

(ii) Which cells produce these chemicals?

(iii) State the function of these molecules.

Ans. (a) A-Antigen binding site B-Light chain

(b) B-lymphocytes.

(c) Heavy Chain

(d) Antibodies provide acquired immune response.


14. Mention any three causes of drug abuse. Suggest some measures for the prevention and control of drug abuse.

Ans. Reasons to attract towards drug abuse: Curiosity, peer pressure, escape from

frustration and failure, family problems, false belief of enhanced performance.

Preventive measures:


Avoid undue peer pressure


Education and Counselling


Seeking help from parents and peers.


Looking for danger signs


Seeking professional and medical help


15. A person shows unwelcome immunogenic reactions while exposed to certain substances.

(a) Name this condition.

(b) What common term is given to the substances responsible for this


(c) Name the cells and the chemical substances released which cause such


Ans. (a) Allergy

(b) Allergens

(c) Mast Cells — Histamine, Serotonin



1. A nitrogen fixing microbe associated with the fern Azolla in rice fields is

(a) Frankia

(b) Rhizobium

(c) Spirulina

(d) Anabaena

Ans: (d) Anabaena


2. Azolla pinnata has been found to be an important biofertiliser for paddy

crops. This quality is due to the presence of

(a) N2 fixing bacteria

(b) N2 fixing cyanobacteria

(c) mycorrhizae

(d) all of these

Ans: (b) N2 fixing cyanobacteria


3. Which of the following is widely used as a successful biofertiliser in

Indian rice field?

(a) Rhizobium

(b) Acacia arabica

(c) Acalypha indica

(d) Azolla pinnata

Ans: (d) Azolla pinnata


4. Which of the following options includes biofertilizers?

(a) cow dung manure and farmyard waste

(b) A quick growing crop ploughed back into the field

(c) Nostoc, Oscillatoria

(d) All of these

Ans: (c) Nostoc, Oscillatoria


5. Which of the following is a non-symbiotic biofertilizer?

(a) VAM

(b) Azotobacter

(c) Anabaena

(d) Rhizobium

Ans: (b) Azotobacter


6. Nitrogen fixation in root nodules of Alnus is brought about by

(a) Frankia

(b) Azorhizobium

(c) Bradyrhizobium

(d) Clostridium

Ans: (a) Frankia


1. Lactate fermentation does not give off CO2. True

2. High biological oxygen demand in a water body means Water is not polluted. False

3. The guts of various ruminants contain Acidophiles. False

4. Aspergillus microbes are used for the commercial production of citric

acid. True

5. Saccharomyces cerevisiae is used primarily for Baking. True


Fill in the blanks in the different columns of the table given below to identify the no. 1 to 6


Ans. (i) Alveoli filled with fluid, reduced breathing, fever, chills, cough and headache.

(ii) Salmonella typhi

(iii) Common Cold

(iv) Internal bleeding, muscular pain, anaemia, fever and blockage of the intestinal


(v) Microsporum species/Trichophyton species/Epidermophyton Species.

(vi) Amoebiasis/Amoebic dysentery



1. In the given flow diagram, the replication of retrovirus in a host cell is

shown. Examine it and answer the following questions

(a) Why is virus called reterovirus?

(b) Fill in (1) and (2)

(c) Can infected cell survie while viruses are being replicated and released by

host cell?


2. What is innate immunity? List the four types of barriers which protect the body from the entry of the foreign agents.


3. How does humoral immune system works when our body is infected?


4. It was diagnosed by a specialist that the immune System of the body of a patient has been suppressed. Describe the infection & the mechanism of its proliferation in the body.


5.(i) Differentiate between communicable & non — communicable diseases?

(ii) Name the body part & the host in which following events takes place in life

cycle of plasmodium.

(a) fertilization

(b) Development of Gametophyte

(c) Release of sporozoites

(d) Asexual Reproduction

Chapter 8 Human Health and Disease