CBSE Class 12 Biology Human Health and Disease Assignment Set A

Important Questions for NCERT Class 12 Biology Human Health and Diseases

Question. Which industrial products are synthesised from microbes?
I. Antibiotics
II. Toddy
III. Bioactive molecules
IV. Bread
Choose the correct option.
(a) I, II, III and IV
(b) II, III and IV
(c) I and IV
(d) III and IV

Answer : C

Question. In the primary treatment of sewage, the soil and small pebbles are removed by
(a) filtration
(b) sedimentation
(c) condensation
(d) evaporation

Answer : B

Question. Which one of the following antibiotics was extensively used to treat American soldiers wounded in World War-II?
(a) Streptokinase
(b) Penicillin
(c) Statins
(d) Neomycin

Answer : B

Question. In the biological treatment of sewage, the masses of bacteria held together by fungal filament to formm esh-like structures called as
(a) activated sludge
(b) aerobic process
(c) flocs
(d) anaerobic sludge

Answer : C

Question. Choose the correct option to fill in the blanks.
I. Primary treatment of sewage involves physical removal of small and large particles through ...A... and ...B... .
II. Microbes consume the major part of organic matter in the effluent and reduce ...C... of sewage.
III. ...D... particularly ...E... anaerobically breakdown cellulosic material and produce CO2 andH2 fromana robic sludge during ...F... . treatment.
IV. WhenBODof sewage has reduced, the effluent is passed into ...G... . Here, AtoGcan be
(a) A–sedimentation, B–centrifugation, C–BOD, D–Methanogen, E–Methanobacterium, F–water gas plant, G–settling tank
(b) A–centrifugation, B–sedimentation, C–BOD, D–Methanogen, E–Methanococcus, F–biogas plant, G–sludge tank
(c) A–filtration, B–centrifugation, C–BOD,D–Methanogen, E–Methanobacillus, F–gobar gas plant, G–filtre tank
(d) A–filtration, B–sedimentation, C–BOD, D–Methanogen, E–Methanobacterium, F–sewage treatment plant, G–settling tank

Answer : D

Question. Primary sludge 
(a) possesses flocs of decomposer microbes
(b) requires aeration for formation
(c) involves little decomposition
(d) forms during secondary sewage treatment

Answer : A

Question. During sewage treatment, biogas is produced, which includes 
(a) methane, hydrogen sulphide and carbon dioxide
(b) methane, oxygen and hydrogen sulphide
(c) hydrogen sulphide, methane and sulphur dioxide
(d) hydrogen sulphide, nitrogen and methane

Answer : A

Question. Microbes are used in
I. primary treatment of sewage.
II. secondary treatment of sewage.
III. anaerobic sludge digesters.
IV. production of biogas.
Choose the correct option.
(a) I, II and III
(b) I, III and IV
(c) II, III and IV
(d) All of the above

Answer : C

Question. Sewage contains large amounts of …A… and …B… .Here A and B refer to
(a) A–inorganic matter, B–bacteria
(b) A–organic matter, B–pathogenic microbes
(c) A–organic matter, B–virus
(d) A–inorganic matter, B–pathogenic microbes

Answer : B

Question. Primary treatment of wastes is the
(a) physical removal of large and small particles from sewage
(b) biological removal of large and small particles from sewage
(c) Both (a) and (b)
(d) chemical removal of large and small particles from sewage

Answer : C

Question. In the primary treatment of sewage, the floating debris is removed by sequential ... by passing through wire mesh screens. The most appropriate word for filling the blank is
(a) filtration
(b) sedimentation
(c) condensation
(d) evaporation

Answer : C

Question. Gobar gas generation technology in India was developed by the collaboration of ...A... and ...B... .
Here, A and B refer to
(a) A–Rural Bank of India, B–Khadi and Village Industries Commission
(b) A–Indian Agricultural Research Institute, B–Khadi and Village Industries Commission
(c) A–National Bank for Agriculture and Development, B–Indian Agricultural Research Institute
(d) A–National Bank for Agriculture and Development, B–Khadi and Village Industries Commission

Answer : B

Question. The BOD test measures the rate of uptake of oxygen by microbes in water bodies. The greater BOD of sample water, indicates that
(a) it is highly polluted
(b) it is not polluted
(c) it is moderately polluted
(d) pollution level cannot be determined

Answer : A

Question. Which of the following plans has been initiated by the Ministry of Environment and Forests to protect rivers from water pollution?
(a) Ganga action plan
(b) Yamuna action plan
(c) Both (a) and (b)
(d) None of the above

Answer : C

Question. Which of the following are the part or example of symbiotic mutualistic association?
(a) Rhizobium
(b) Mycorrhiza
(c) Both (a) and (b)
(d) Oscillatoria

Answer : C

Question. A biocontrol agent to be a part of an integrated pest management should be 
(a) species-specific and symbiotic
(b) free-living and broad spectrum
(c) narrow spectrum and symbiotic
(d) species-specific and inactive on non-target organisms

Answer : D

Question. Which one of the following is an example of carrying out biological control of pests/diseases using microbes?
(a) Trichoderma sp., against certain plant pathogens
(b) Nucleopolyhedrovirus against white rust in Brassica
(c) Bt cotton to increase cotton yield
(d) Ladybird beetle against aphids in mustard

Answer : A

Question. Which of the following is cyanobacteria and fix atmospheric nitrogen?
(a) Oscillatoria
(b) Nostoc
(c) Anabaena
(d) All of these

Answer : D

Question. In the sewage treatment, bacterial flocs are allowed to sediment in a settling tank. This sediment is called as
(a) activated sludge
(b) primary sludge
(c) anaerobic sludge
(d) secondary sludge

Answer : A

Question. The most common fungal partner of mycorrhiza belongs to genus
(a) Azotobacter
(b) Glomus
(c) Azolla
(d) Frankia

Answer : B

Question. Which one of the following helps in absorption of phosphorus from soil?
(a) Nostoc
(b) Anabaena
(c) Glomus
(d) Yeast

Answer : C

Question. The most flammable gaseous component of biogas is
(a) methane, CO2, H2 and H S 2
(b) methane
(c) CO2, H2 and H S 2
(d) CO, methane and N2

Answer : B

Question. Organic farming includes
(a) use of fertilisers and pesticides of biological origin
(b) IPM (Integrated Pest Management)
(c) locally developed pest resistant varieties
(d) All of the above

Answer : D

Question. The organisms which are used to enrich the nutrient quality of the soil are
(a) bacteria
(b) cyanobacteria
(c) fungi
(d) All of these

Answer : D

Question. Methanogens are found in
I. organic acid II. rumen of cattle
III. butanal IV. anaerobic sludge
Choose the correct option.
(a) I and II
(b) II and III
(c) II and IV
(d) III and IV

Answer : C

Question. Which of the following bacteria is present in the rumen of cattle?
(a) Rhizobium
(b) Azotobacter
(c) Methanobacterium
(d) Clostridium

Answer : C

Question. Which of the following is common to Azospirillum, Anabaena, Nostoc and Oscillatoria?
(a) N2-fixer microbes
(b) Prokaryotic organism
(c) Both (a) and (b)
(d) Eukaryotic organism

Answer : C

Question. The factor which has effect on health is :-
(a) Genetic disorders
(b) Infections
(c) Life style
(d) All of the above

Answer : D

Question. Which is required for maintenance of good health ?
(a) Balanced diet
(b) Personal hygiene
(c) Regular exercise
(d) All of the above

Answer : D

Question. Which is necessary for achieving good health?
(a) Awareness about diseases
(b) Proper disposal of wastes
(c) Control of vectors
(d) Maintenance of hygienic food and water
(a) a
(b) a and c
(c) b and c
(d) a, b, c and d

Answer : D

Question. Which is related with ringworm ?
(a) Microsporum
(b) Trichophyton
(c) Epidermophyton
(a) a
(b) a, b
(c) a, c
(d) a,b,c

Answer : D

Question. (a) Salmonella is pathogenic bacterium
(b) Sustained high fever (39°C to 40°C)
(c) Intestinal perforation in severe cases
(d) Confirmed by "widal test"
(e) "Marry Mallon" was a carrier Above statements are true for :-
(a) Plague
(b) Diphtheria
(c) Typhoid
(d) Dysentery

Answer : C

Question. Find the odd one out with regards to secondary immune response :-
(a) Booster
(b) Anamnestic
(c) Low intensified
(d) Develops after subsequent contact of same antigen

Answer : A

Question. Which immune response / immunity is mainly responsible for graft rejection ?
(a) Cell-mediated
(b) Humoral
(c) Antibody mediated
(d) All of the above

Answer : A

Question. The period between.......of age may be thought of as adolescence period
(a) 18-21 yrs.
(b) 12-21 yrs.
(c) 12-18 yrs.
(d) 18-25 yrs.

Answer : C

Question. Antibodies are found in :-
(a) Blood
(b) Pathogen
(c) Antigen
(d) Neurons

Answer : A

Question. The drugs, which are commonly abused are opioid,cannabinoids and coca alkaloid. Majority of these are obtained from........., while some are obtained from .........
(a) Fungi, non-flowering plants
(b) Flowering plants, fungi
(c) Fungi, flowering plants
(d) Non flowering plants, fungi

Answer : B

Question. Above statements/informations are correct for:-
(a) Smack (b) Diacetylmorphine
(c) White (d) Odourless
(e) Bitter crystalline compound (f) Extracted from latex of poppy plant
(a) Morphine
(b) Heroin
(c) Cocain
(d) Barbiturates

Answer : B

Question. ATS provides :-
(a) Natural active innate immunity
(b) Natural passive innate immunity
(c) Artificial active acquired immunity
(d) Artificial passive acquired immunity

Answer : D

Question. Which cell acts as factory of HIV ?
(a) Macrophage
(b) TH cells
(c) TK cells
(d) N.K. cells

Answer : A

Question. In full blown AIDS, opportunistic infections are especially caused by :-
(a) Mycobacterium
(b) Toxoplasma
(c) Viruses and fungi
(d) All of the above

Answer : D

ASSERTION REASON TYPE

A. Both A & R are True and R is the correct explanation of A.
B. Both A & R are True and R is not the correct explanation of A.
C. A is True but R is False.
D. A is False but R is True.

Question. Assertion (A) - Female Anopheles mosquito is the pathogen for Malaria.
Reason (R)- Mosquito can transmit plasmodium.

Answer :

Question. Assertion (A) - Heroin is an opioid.
Reason (R) - Heroin is obtained from poppy plant.

Answer : B

Question. Assertion (A) - Cannabinoids can affect cardiovascular system of body.
Reason (R)- Ganja is a cannabinoid.

Answer: B

Question. Assertion (A) - Small children have more immunity
Reason (R)- Thymus is quite large at the time of birth.

Answer: A

Question. Assertion (A) - Excessive dosage of cocaine causes hallucinations.
Reason (R) - Atropa belladona and Datura have hallucinogenic properties.

Answer: B

Question. Assertion (A) - Anamnestic responses are highly intensified.
Reason (R) - Secondary response are due to memory of the first encounter.

Answer: A

Question. Assertion (A) - Genetic disorders are infectious.
Reason (R) - Genetic disorders are inherited from parents to their children.

Answer: D

Question. Assertion (A) - C-onc are cells that can cause cancer.
Reason (R) - C-onc are cellular organisms.

Answer: D

Question. Assertion (A) - Smoking causes raise in blood pressure and increases heart rate.
Reason (R)- Nicotine stimulates adrenal gland to release adrenaline and noradrenaline.

Answer: A

Question. Assertion (A) - Rheumatoid arthritis is an auto-immune disease.
Reason (R) - Here, body attacks self-cells.

Answer: A

Question. Assertion (A) - Asexual reproduction of plasmodium takes place in the Gut of Mosquito.
Reason (R) - Sporozoites are formed in the Gut of Mosquito.

Answer: D

Question. Assertion (A) - AIDS and Hepatitis-B are viral diseases.
Reason (R) - These diseases are transferred from one person to another by sharing of infected needles and syringes.

Answer: B

Question. Assertion (A) - Using morphine for medical purpose is a case of drug abuse.
Reason (R) - Morphine is a very effective sedative and painkiller.

Answer: D

Question. Assertion (A) - Pneumonia causes severe respiratory problems.
Reason (R) - Due to infection, alveoli of lungs get filled with fluid.

Answer: A

Very Short Answer Type Questions:

Question. What would happen to the immune system, if thymus gland is removed from our body?
Answer: T lymphocytes produced from bone marrow and migrate to thymus gland for maturation
If thymus gland is removing that will result in weak immune system.

Question. Why is a person with cuts and bruises following an accident administered tetanus antitoxin?
Answer: Tetanus is caused by deadly bacterium; quicker response is required. So, performed antibodies /antitoxin is administered, to neutralize the effect of bacterial toxin.

Question. How are morphine and heroin related? Mention the effect each one of them has on the human body?
Answer: Heroin is obtained by acetylation of morphine which is obtained from the latex of poppy plant Effect-slows down body functions, depression.

Question. Explain the relationship between B-lymphocytes and T-lymphocytes in developing an immune response?
Answer: B-lymphocytes produce antibodies to fight pathogen.

Question. Why is tobacco smoking associated with rise in blood pressure and emphysema (oxygen deficiency in the body)? Explain.
Answer: Tobacco has nicotine that stimulates the release of adrenaline and noradrenaline which raise blood pressure. Smoking tobacco releases carbon monoxide which reduces the concentration of haem-bound oxygen. This causes emphysema.

Question. Name and explain 4 lymphoid organs present in humans.
Answer: Primary lymphoid organs- bone marrow and thymus gland-immature lymphocyte differentiate into antigen sensitive lymphocytes. Secondary lymphoid organ-spleen and lymph nodes-provide sites for interaction of tes lymphocy with antigen.

Question. If a regular dose of drugs or alcohol is not provided to an addicted person, he shows some withdrawal symptoms. List any four such withdrawal symptoms.
Answer: The withdrawal symptoms are:
(a) Anxiety (b) Shakiness
(c) Nausea (d) Sweating

Question. A farmer while working on his farm was bitten by a poisonous snake. The workers in the farm immediately rushed him to the nearby health centre. The doctor right away gave him an injection to save his life. What did the doctor inject and why?
Answer: The doctor injected an antivenom. 
The antivenom contains preformed antibodies which when
Injected act on the pathogen immediately provide protection by providing passive immunity.

Question. What is an autoimmune disease? Give an example.
Answer: When body attacks self-cells Rheumatoid arthritis.

Question. With the help of diagram explain structure of antibody molecule.
Answer: Labelled diagram , Structure

Question. Why an immunosuppressive agent is taken after an organ transplant?
Answer: Our immune system is capable to differentiate between ‗self‘ and ‗non-self‘ cells/tissues.
The graft (grafting) is a non-self-tissue which may be rejected by our immune system. So, to Prevent the rejection, immunosuppressants are taken after the transplant.

Question. Name the plant source of the drug popularly called ―smack‘. How does it affect the body of the abuser?
Answer: Plant source of ‗smack‘ is Papaver somniferum or poppy.
Smack is a depressant and slows down body functions.

Question. What is colostrum? Why is it important to be given to the newborn infants?
Answer: The milk that comes out of the mammary glands during initial days of lactation is called colostrum.
It contains several antibodies (IgA most abundantly), absolutely essential for developing resistance in The newborn babies.

Question. What is the role of histamine in inflammatory response? Name two drugs which reduce the symptoms of allergy.
Answer: Histamine is produced by mast cells which acts as allergy mediator which cause blood vessels to dilate Anti-histamines, adrenalin, steroids quickly reduce the symptoms.

Question. Name the causative organism of the disease Amoebiasis. List three symptoms of this disease.
Answer: Entamoeba histolytica Symptoms-constipation, abdominal pain, cramps, stool with blood clots/excess mucous. 

Question. Differentiate between innate immunity and acquired immunity.
Answer: Innate immunity -nonspecific type of defense, present from the time of birth
Acquired immunity- pathogen specific, acquired after birth, due to disease or vaccination.

Question. Write the source and effect on the human body of the following drugs.
1.Cocaine 2.opioids
Answer: Cocaine –from coca plant (Erythroxylum coca)
It acts on central nervous system producing sense of euphoria and increased energy
opioids-from poppy plant (Papaver somniferum)
Affect central nervous system, depressant and slows down body functions

Question. Write the events that take place when a vaccine for any disease is introduced into the human body.
Answer: Antibodies are produced in the bodies against the antigens of the disease, which would neutralize the antigens during actual infection Cause production of B cells and T cells that recognize the pathogen quickly on subsequent exposure.

Question. What are interferons? Mention their role.
Answer: These are glycoproteins which protect non-infected cells from further viral infection.
It is a type of innate immunity (cytokine barrier).
 

Short Answer Type Questions:

Question. (a) Differentiate between benign & malignant tumors. (b)Why is colostrum a boon to new born baby?
Answer: Benign tumor-remains confined to the original location.
Does not spread to other parts of the body
Malignant tumor-mass of proliferating cells that invade and damage surrounding tissues.
Spread to different parts of the body (metastasis).

Question. A farmer while working on his farm was bitten by a poisonous snake. The workers in the farm immediately rushed him to the nearby health center. The doctor right away gave him an injection to save his life. What did the doctor inject and why? Explain
Answer: Antitoxin/antivenoms/performed antibodies
Quick response is required
To neutralize snake venom quickly passive immunity is provided

Question. How is the normal human body temperature of 37°C maintained during (i) Summer, and (ii) Winter? Explain. 
Answer: Human beings maintain a constant temperature of 37°C.
In summers, the outside temperature is much higher than our body temperature. Therefore, we sweat profusely. This results in evaporative cooling, and our body temperature is reduced to normal.
In winters, the outside temperature is much lower than our body temperature. Therefore, we shiver, which is a kind of exercise, which produces heat and raises the body temperature.

Question. Why is the structure of an antibody molecule represented as H2L2? Name any two types of antibodies produced in a human body.
Answer: L2 = Two light / small polypeptide chains, H2= two heavy / longer polypeptide chains. IgA / IgM / IgE / IgG. (Any two)

Question. Name the type of immunity a baby is born with. How is it different from the one he gets from the mother’s milk after birth ?
Answer: Innate Immunity-Acquired Immunity that a baby acquires from his mother's milk after birth is an example of passive immunity. 

Question. Differentiate between the roles of B-lymphocytes and T-lymphocytes in generating immune responses.
Principle of vaccination is based on the property of “memory” of the immune system.
Taking one suitable example, justify the statement.
Answer: B-lymphocytes : Produce antibodies T-lymphocytes : Help B-lymphocytes to produce antibodies / kills the pathogen directly (Killer T-cells).
                                          OR
When a vaccine / heat killed pathogen / attenuated pathogen / weakened pathogen / a preparation of antigenic proteins of pathogen is introduced into the body to prevent chicken pox / measles / any other example. It produces antibodies against antigen / pathogen.  It generates B and T memory cells that recognize the pathogen quickly on subsequent exposure , to produce large amount of antibodies that inactivate the pathogen causing the disease. +
(Any other correct example of a disease can also be substituted)

Question. List two diseases that spread through inhaling droplets or aerosols. Write one prominent symptoms for each one of them.
Answer: Diseases that spread through inhaling droplets and aerosols are Diphtheria and Common cold.
Symptoms of Diphtheria : Sore throat and swollen lymph nodes.
Symptoms of Common cold : Nasal congestion and sneezing. 

Question. (i) Which organ of the human body is initially affected when bitten by an infected female Anopheles? Name the stage of the parasite that infects this organ.
(ii) Explain the events that are responsible for chill and high fever in the patient.
Answer: (i) Liver cells, sporozoites.
(ii) Parasites reproduce asexually in RBC / multiply, Rupture of RBCs is associated with release of toxic substance called as hemozoin.

Question. (a) Name the source plant of heroin drug.
How is it obtained from the plant?
(b) Write the effects of heroin on the human body.
Answer: (a) Papaver somniferum / Poppy plant.
Extracted from latex of the plant / acetylation of morphine (obtained from the latex of plant).
(b) Depressant, slows down body function.

Question. What is a vaccine ? How does it act to provide long term immunity to an individual who is vaccinated ?
Answer: A vaccine is an antigen protein of pathogens or inactivated or weakened pathogens or their toxin. When it is introduced into the body of a person who is required to be made immune, it stimulates the production of antibodies and memory cells which is called primary response. It produces memory cells when this pathogen enters the second time. These memory cells show rapid and massive responses so that body become immune to this pathogen.

Question. Name and state the effect of a drug that is often medically prescribed, but its overuse leads to drug dependence and drug abuse.
Answer: Morphine, barbiturate, amphetamines, benzodiazepines,
lysergic acid diethyl amides (LSD).
Affects the central nervous system, acts as a pain killer, acts as a sedative, treats depression, treats insomnia, creates hallucinogenic effect.

Question. a). Why is there a fear amongst the guardians that their adolescent wards may get trapped in drug /alcohol abuse?
b) Explain addiction and dependence in respect of drug/alcohol abuse in youth
Answer: a) Adolescents are easily affected by peer pressure/adventure/curiosity/excitement /experimentation 
b). Addiction-psychological attachment to certain effects such as euphoria/temporary feeling of wellbeing.
Dependence-tendency of body to show withdrawal syndrome/symptoms if regular doses of drug /alcohol is abruptly discontinued.

Question. Name the form of Plasmodium that enters the human body. Explain the different stages of its lifecycle in the human body.
Answer: Sporozoites
Sporozoites reach the liver through blood
The parasites reproduce asexually in liver cells Parasites reproduces asexually in RBC Bursting RBC and enter into blood Gametocytes develop in RBC.

Question. During a school trip to ‗Rohtang Pass‘, one of your classmates suddenly developed ‗altitude sickness‘. But, she recovered after sometime.
(a) Mention one symptom to diagnose the sickness.
(b) What caused the sickness?
(c) How could she recover by herself after sometime
Answer: (a) Nausea/fatigue/heart palpitation
(b) The sickness was caused due to low atmospheric pressure at high altitude because of which the body was deprived of oxygen.
(c)The body compensates low oxygen availability by increasing RB production decreasing the (Any two points) binding capacity of haemoglobin and by increasing breathing rate.

Question.(a) All human beings have cellular oncogenes but only a few suffer from cancer disease. Why?
(b) How is a malignant tumour different from a benign tumour?
Answer: All humans have cellular oncogenes or proto-oncogenes, but only a few suffer from cancer because cancer only occurs on activation of oncogenes. This activation is induced by carcinogens which can be physical, chemical or biological. The chemical carcinogens present in tobacco and smoke have been identified as a major cause of lung cancer.

Question. Prior to a sports event, blood and urine samples of sports persons are collected for drug tests.
(a) Why is there a need to conduct such tests?
(b) Name the drugs the authorities usually look for.
(c) Write the genetic names of two plants from which these drugs are obtained.
Answer: (a) Such tests are conducted to detect drug abuse to ensure fair game.
(b) The authorities look for cannabinoids, cocaine, coca alkaloid, coke, crack, hashish, charas,ganja and hemp plant extract.
(c) These drugs are obtained from Cannabis, Atropa, Erythroxylum, and Datura.

Question. What is innate immunity Write the 4 types of barriers which protect the body from the entry of the foreign agents.
Answer: Innate immunity is nonspecific type of defense that is present at the time of birth.
a) Physical barriers, physiological barriers, cellular barriers, cytokine barriers. 

Question. (a) Why is there a fear amongst the guardians that their adolescent wards may get trapped in drug/alcohol abuse
(b) Explain 'addiction‘ and 'dependence‘ in respect of drugs/alcohol abuse in youth.
Answer: (a) Adolescents are easily affected by (or are vulnerable to) peer pressure. Curiosity, need for adventure and excitement, and experimentation constitute common
causes for motivation. A Child‘s natural curiosity motivates him/her to experiment. Television, movies, newspapers, Internet also promote drug use.
(b) Addiction is the psychological attachment to certain effects such as euphoria or temporary feeling of well-being.
(c) Dependence is the tendency of the body to show withdrawal syndrome or symptoms if regular doses of drug/alcohol are abruptly discontinued.

Question. (a) Name and explain giving reasons the type of immunity provided to the new born by colostrum and vaccinations
(b) Name the type of antibody
1. Present in colostrum
2. Produced in response to allergens in human body.
Answer: Passive immunity
When readymade antibodies are directly given to protect the body against foreign agents
Active immunity.
When a host is exposed to antigens which may be forms of living or dead microbes or other protein are produced in the host body
b) 1. IgA
2. IgE

Question. How does the HIV break down the immune system of the AIDS patients?
Answer: Virus enters in macrophages.
RNA genome replicates to form viral DNA with the help of reverse transcriptase Viral DNA gets in corporated in to host cell‘s DNA to produce virus particles. HIV enters into helper T cells and produce Progeny virus. These are released into the blood and attack other T helper cells. The no. of T helper Cells decreases and the person starts suffering from infections (loss of immunity).

Question. Name the disease in which immune system of a person is suppressed. Name the causal organism and diagnostic technique of this disease.
Answer: AIDS-Acquired Immuno Deficiency Syndrome
Caused by HIV-Human Immuno Deficiency Virus
ELISA-Enzyme Linked Immuno Sorbant Assay

Question. a). It is generally observed that the children who had suffered from chicken pox in their childhood may not cause the same disease in their adulthood.
Explain giving reasons the basis of such immunity in an individual. Name the kind of immunity.
b) What is interferon? Mention their role
Answer: a). First infection produce primary response and antibodies are generated against chickenpox virus encounter subsequently with the same virus elicits a highly intensified secondary response Due to the memory cells formed during the first encounter, Active immunity.
b) Proteins secreted by viral infected cells which protects non-infected cells from viral infection/When alpha interferon is given to cancer patients (it activates immune system) destroys tumor.

Question. When someone buys packets of cigarettes, cannot miss the statutory warning that is present on the packing which warns against smoking and says how it is injurious to health. Yet, smoking is very prevalent in our society, both among young and old. Advise the adolescents about the importance of avoiding smoking.
Answer: (i) Tobacco in cigarettes contains a large number of chemical substances including 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.
(ii) Smoking is associated with increased incidence of cancers of lung, urinary bladder, throat and oral cavity.
(iii) It is responsible for bronchitis and emphysema.
(iv)It is associated with increased risk of coronary heart disease, gastric ulcer, etc.
(v) Smoking increases carbon monoxide (CO) content in blood and reduces the concentration of haem-bound oxygen.
(vi)This causes oxygen deficiency in the body.

Long Answer Type Questions :

Question. Describe the lymphoid organs of the body and their role.
Answer: 
● These are the organs where origin and/or maturation and proliferation of lymphocytes occur.
● The primary lymphoid organs are bone marrow and thymus where immature lymphocytes differentiate into antigen sensitive lymphocytes.
i) Bone marrow: Bone marrow present in the bones is the main lymphoid organ where all blood cells including lymphocytes are produced. Bone marrow provides the micro environment for the development and maturation of B lymphocytes.
ii) Thymus: Thymus is located beneath the breastbone. Thymus is quite large at the time of birth but keeps reducing with age. It Provides microenvironment for the development and maturation of T lymphocytes.
Secondary lymphoid organs: The lymphocytes after maturation migrate to secondary lymphoid organs like spleen, lymph nodes, tonsils,Peyer's patches of small intestine and appendix. Secondary lymphoid organs provide sites for interaction of lymphocytes with antigen, which then proliferate to become effector cells.
i. Spleen: Spleen mainly contains lymphocytes and phagocytes. It acts as a filter of the blood by trapping blood borne microorganisms. Spleen has a large reservoir of erythrocytes.
ii. Lymph nodes: Lymph nodes are small solid structures located at different points along the lymphatic system. Lymph nodes serve to trap the microorganisms or other antigens, which happens to get into lymph.
iii. MALT- Mucosal associated lymphoid tissue. Lymphoid tissue located within the lining of major tracts (respiratory, digestive, urogenital) is called MALT.
iv. Lymphoid tissue associated with the gut is called peyer's patches.

Question. Trace the events that occur in the human body to cause immune deficiency, when HIV enters the body.
Answer: ▪ HIV enters into macrophages where it synthesizes viral DNA from RNA genome, with the help of enzyme reverse transcriptase.
▪ This viral DNA gets incorporated into the host cell‘s DNA and direct the infected cells to produce viral particles.
▪ The macrophages continue to produce viruses and in this way acts like an HIV factory.
▪ HIV enters into helper T-lymphocytes, replicates and produce progeny viruses.
▪ The progeny viruses released in blood attack other helper T lymphocytes in the body of the infected person.
▪ Due to decrease in the number of T lymphocytes, t iTnofexcotpiolans mduae. to bacteria such as Mycobacterium, vhireu pseesrs, ofunn sgtai ratns ds uefvfeenri npga rfarsoim
▪ The patient becomes so immunologically deficient and unable to fight against such infections.

Question. What is the basic principle of vaccination? How do vaccines prevent microbial infections?
(b) Name the organism from which Hepatitis b vaccine is produced.
(c) Differentiate between B -cells and T- cells
Answer: a) Principle of vaccination is based on the property of memory of immune system. In vaccination, a preparation of antigenic proteins of pathogens or inactivated /live but weakened pathogens is introduced into the body. The antigens generate primary immune response by producing antibodies along with formation of memory B cells and T cells. When the vaccinated person attacked by the same pathogen, the existing Memory B cells and T cells recognize the antigen and overwhelm the invaders with massive production of lymphocytes and antibodies.
b) Hepatitis B vaccine is produced from Yeast. 

Question. What are the methods of cancer detection? Describe the common approaches for treatment of cancer?
Answer: Detection of cancer:
● Biopsy of affected tissue
● Histopathological studies
● Techniques such as radiography (x rays) CT scan, and MRI
Treatment:
● Surgery: Removal of entire cancerous tissue
● Radiation: Exposure to X rays which destroy rapidly growing cells without harming the surrounding tissues.
● Chemotherapy: administration of anti-cancerous drugs.
● Treatment by combination of surgery, drugs and radiation therapy.
● Patients are given substances such as biological response modifiers such as alpha interferon, which enables the immune system in detection and destruction of cancer cells.

Question. Briefly describe the life history of malarial parasite.
Answer: i. Ascariasis:
Pathogen: Caused by Ascaris lumbricoides
Symptoms: Blockage of intestinal passage, anemia, abdominal /muscular pain, internal bleeding, nausea and headache.
Modes of transmission: Infection is through contaminated vegetables, fruits and water as eggs of parasites excreted by the infected persons contaminate soil, plants and water.
ii. Filariasis/Elephantiasis
Pathogen: Wuchereria bancrofti and W. malayi
They normally cause the inflammation of the organs in which they live for many years. They normally affect the lymph vessels of the lower limbs (causing them to swell) Genital organs may also affect.
Transmission: Female Culex mosquito is the vector.
iii. Ringworm infection
Pathogen-fungi like Microsporum, Epidermophyton and Trichophyton Symptoms: Dry scaly lesions on the skin,nails and scalp. Lesions are accompanied by itching.

Question. Define drug addiction. Give sources and harmful effects of some drugs derived from different plant sources?
Answer: The prolonged use of drugs may lead the physical and mental dependence of the body on them.
This is called as drug addiction.
(i) Heroin: -
Source - Poppy plant (Papaver somniferum)
effects - Depressant, slows down body functions.
(ii) Cocaine: -
Source - Coca plant (Erythroxylum coca)
Effects - Potent stimulating action on CNS, producing a sense of euphoria and increased energy.
Excessive
dose cause hallucinations.
(iii) Marijuana,Hashish, Charas, Ganga : -
Source - Cannabis plant (Cannabis sativa)
Effects: - Effects on cardiovascular system.

Question. What are opioids. Describe briefly about the various products obtained from opioids?
Answer: These are the drugs, which are obtained from the latex of poppy plant (Papaver somniferum). The exudate of these plants is air dried and is used as opium. Opium is a pain killer drug that acts on CNS. Opium yields the following alkaloids: -
(a) Morphine. It is the main constituent of opium. It is kept in slaked lime and ammonium chloride and then it is filtered to remove impurities and to obtain Morphine. It is a strong analgesic and has sedative and calming effect. It suppresses brain functions and relieves intense pain during fractures, burns & surgery. Brown sugar or smack is diacetyl morphine hydrochloride which is highly analgesic than morphine.
(b) Heroin. It is a white odourless, bitter crystalline powder obtained from morphine on acetylation (diacetyl morphine). It is about three times more potent than morphine and is used as potent pain killer. It is taken by snorting and injection. It reduces anxiety and tension, lowers blood pressure and breathing rate.
(c) Methadone. It is a synthetic opiate which acts as analgesic, respiratory depressant and constipating agent like morphine.
(d) Codeine. It is a natural opiate, occurs in the form of methyl - morphine. It acts as mild analgesic and used as an ingredient of many medicines and cough syrups.
(e) Pethidine (Meperidine). It is a synthetic opiate and acts somewhat similar to Morphine.

Question. Tobacco addiction is due to nicotine present in it. Mention some effects of nicotine on human body.
Answer: Tobacco contains nicotine (an alkaloid) which is a powerful toxin. It has a number of effects on
human body. These are
(i) Nicotine stimulates adrenal gland to release adrenaline and nor-adrenaline in to blood circulation, both of which raise blood pressure and increase heart rate.
(ii) It causes lung cancer,bronchitis, emphysema,coronary heart disease, cancer of urinary bladder and throat,gastric ulcer etc.
(iii) Tobacco chewing causes cancer of the oral cavity.
(iv) Smoking increases CO content in blood and reduces the concentration of haem bound oxygen.
This causes oxygen deficiency in the body.

Question. List some factors which compel the people to take drugs.
Answer: People generally take drugs on the basis of the following factors:
(a) People take drugs to escape from the realities of life, to overcome frustrations and depressions.
(b) Drugs act as a motivation factor for pleasure, fun, curiosity, adventure and to experience different kind of awareness.
(c) People consume drugs under the influence of peer group
(d) People use drug as a result of apathy arising from race,sex and age etc. They start consuming depressant in order to overcome the prophecy of defeat and powerlessness.
(e) They take drug to do more physical or mental work or to get relief from severe pains.

Question. How can alcohol or drugs abuse be avoided among adolescents?
Answer: (i) Avoid undue peer pressure: Every child has his / her own choice and personality, which should be respected and nurtured. A child should not be pushed unduly to perform
beyond his / her threshold limits: be in sports or other activities.
(ii) Education & counselling: The child should be properly counselled to face problems and stresses and to accept disappointments and failure as part of Life.
(iii) Seeking help from Parents and peers: The parents and peers should guide youth and adolescents appropriately for sorting out their problems.
(iv) Looking for danger signs: Friends and teachers should not hesitate to bring it to the notice of their parents if their wards are consuming drugs or alcohol.
(v)Seeking professional and medical help: Lot of help is available in the form of highly qualified psychologists, psychiatrists and de-addiction and rehabilitation programs to help the
individuals who have unfortunately become drug abuser.

Question. Give an account of the following diseases (i) Ascariasis (ii) Filariasis (iii) Ring worms
Answer: i. Malarial parasite completes life cycle in two hosts. i.e, man and female anopheles‘ mosquito.
ii. Sporozoites are the infective stage.
iii. The sporozoites enter the body, reach the liver cells through blood and multiply within the liver cells.
iv. Such liver cells burst and release the parasites into blood.
v. Then they attack RBCs, multiply and cause their rupture.
vi. The rupture of RBCs is associated with the release of toxin called haemozoin, which is responsible for the high recurring fever and the chill and cause malaria.
vii. Sexual stages (gametocytes) develop in the red blood cells
viii. The parasite then enters the female Anopheles mosquito along with blood when it bites an infected person.
ix. Further development occurs in the stomach wall of mosquito.
x. The gametes fuse to form zygote.
xi. The zygote undergoes further development in the body of the mosquito and form sporozoites.
xii. Sporozoites are transported to and stored in the salivary glands of mosquitoes and are transferred to a human body during the bite of mosquito. (2)

Question. Mention one application for each of the following
a) Passive immunization
b) Antihistamine
c) Colostrum
d) Cytokine barrier
e) ELISA
Answer: a) Provide preformed antibodies / anti-toxins for quick response in case of infection by deadly microbes (eg : tetanus) or snake bite
b) Reduces symptoms of allergy
c) Provides passive immunity / antibodies / Ig A to new born
d) Protection of non-infected cells from further viral infection
e) Enzyme Linked Immuno Sorbent Assay- Diagnostic test for AIDS

Case Study 1:

Our mind and mental state can affect our health. Of course, health is affected by- (i) genetic disorders – deficiencies with which a child is born and deficiencies/defects which the child inherits from parents from birth;
(ii) infections and (iii) life style including food and water we take, rest and exercise we give to our bodies, habits that we have or lack etc. When the functioning of one or more organs or systems of the body is adversely affected, characterised by appearance of various signs and symptoms, we say that we are not healthy, i.e., we have a disease. Diseases can be broadly grouped into infectious and non-infectious.
Diseases which are easily transmitted from one person to another, are called infectious diseases. Infectious diseases are very common and every one of us suffers from these at some time or other. Some of the infectious diseases like AIDS are fatal. Among non-infectious diseases, cancer is the major cause of death. Drug and alcohol abuse also affect our health adversely.

Question. If a person‘s organ or organ system is affected then the symptoms will appear. And the person can say.
(a) I am healthy.
(b) I am in good state.
(c) I am unhealthy.
(d) I am resting.
Answer: C

Question. Define the term ‗Infectious disease‘ and write an example.
Answer: Transmission of the diseases from one person to another is called as Infectious diseases. AIDs is an example of infectious disease.

Question. Which of the following thing mainly affects health?
(a) Life style
(b) Education
(c) Genetic disorder
(d) Both (a) and (b)
Answer: D

Question. When the child is born with some deficiencies then it is …………
(a) Heart disease
(b) Genetic disorder
(c) Obesity
(d) Infections
Answer: B

Case Study 2:

A wide range of organisms belonging to bacteria, viruses, fungi, protozoans, helminths, etc., could cause diseases in man. Such disease-causing organisms are called pathogens. Most parasites are therefore pathogens as they cause harm to the host by living in (or on) them. The pathogens can enter our body by various means, multiply and interfere with normal vital activities, resulting in morphological and functional damage. Pathogens have to adapt to life within the environment of the host. For example, the pathogens that enter the gut must know a way of surviving in the stomach at low pH and resisting the various digestive enzymes. A few representative members from different groups of pathogenic organisms are discussed here along with the diseases caused by them.
Preventive and control measures against these diseases in general, are also briefly described. Salmonella typhi is a pathogenic bacterium which causes typhoid fever in human beings. These pathogens generally enter the small intestine through food and water contaminated with them and migrate to other organs through blood. Sustained high fever (39° to 40°C), weakness, stomach pain, constipation, headache and loss of appetite are some of the common symptoms of this disease. Intestinal perforation and death may occur in severe cases.
Typhoid fever could be confirmed Widal test : A classic case in medicine, that of Mary Mallon nicknamed Typhoid Mary, is worth mentioning here. She was a cook by profession and was a typhoid carrier who continued to spread typhoid for several years through the food she prepared.

Question. Write the name of pathogenic bacteria that causes typhoid and its symptoms.
Answer: A pathogenic bacterium that causes typhoid fever in humans is Salmonella typhi.
Salmonella typhi causes typhoid by entering small intestine. The common symptoms of typhoid disease are weakness, high fever, and loss of appetite, constipation, and headache.

Question. Why most of parasites are pathogens?
Answer: Parasites live in or on the host and causes harm to the host. Hence, most of parasites are pathogens.

Question. In a classic case, who was spreading typhoid by cooking?
(a) Mary Mallon
(b) Typhoid Cook
(c) Classic Mallon
(d) Mary Classic
Answer: A

Question. The organisms like viruses, helminths, protozoa and bacteria which are responsible for causing disease in man are known as …....
(a) Non-Infectious
(b) Enzymes
(c) Typhoid
(d) Pathogens
Answer: D

Case Study 3:

Bacteria like Streptococcus pneumoniae and Haemophilus influenzae are responsible for the disease pneumonia in humans which infects the alveoli (air filled sacs) of the lungs. As a result of the infection, the alveoli get filled with fluid leading to severe problems in respiration. The symptoms of pneumonia include fever, chills, cough and headache. In severe cases, the lips and finger nails may turn gray to bluish in colour. A healthy person acquires the infection by inhaling the droplets/aerosols released by an infected person or even by sharing glasses and utensils with an infected person. Dysentery, plague, diphtheria, etc., are some of the other bacterial diseases in man. Many viruses also cause diseases in human beings. Rhino viruses represent one such group of viruses which cause one of the most infectious human ailments – the common cold. They infect the nose and respiratory passage but not the lungs.
The common cold is characterised by nasal congestion and discharge, sore throat, hoarseness, cough, headache, tiredness, etc., which usually last for 3-7 days. Droplets resulting from cough or sneezes of an infected person are either inhaled directly or transmitted through contaminated objects such as pens, books, cups, doorknobs, computer keyboard or mouse, etc., and cause infection in a healthy person.

Question. By which of the following reason, an healthy person can acquire pneumonia disease?
(a) By exhaling droplets of non-infected person.
(b) By headache or leg pain.
(c) By eating fast food.
(d) By inhaling droplets of infected person.
Answer: D

Question. How long does common cold last?
Answer: Common cold usually last for three to Seven days.

Question. Write any two symptoms of common cold and pneumonia.
Answer: Common cold manly infects respiratory passage and pneumonia mainly infects alveoli. Symptoms of common cold are sore throat, cough and headache etc., and symptoms of
pneumonia are fever, cough and chills etc. Fingers and lips turn gray to bluish colour in severe cases.

Question. which organ in the humans get affected by pneumonia disease?
(a) Stomach
(b) Heart
(c) Lungs
(d) Bladder
Answer: C

Question. Rhino virus can infect ………………………………………… in the humans.
(a) Hand
(b) Nose
(c) Ear
(d) Hairs
Answer: B

 

1. Name the diagnostic test which confirms typhoid.

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

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

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

5. Name the pathogen which causes malignant malaria.

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

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

 

(3 MARKS)

13. What are Cannabinoids? From which plant Cannabinoids are obtained?

Which part of the body is affected by consuming these substances?

14. 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.

 

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

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 condition?

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

 

Please refer to attached file for CBSE Class 12 Biology Human Health and Disease Assignment Set A