CBSE Class 12 Biology Human Health and Disease MCQs Set J

Question: LSD is obtained from
a) Cannabis sativus
b) Papaver somniferum
c) Erythroxylon cocca
d) Claviceps purpurea
Answer: d

Question: The cell in the human body invaded by the human immunodeficiency virus (HIV) is
a) Erythrocyte
b) B-cell
c) Macrophage
d) T-helper cell
Answer: d

Question: Metastasis is
a) Fast mitosis in cancer cells
b) Transfer of cancer cells from one part of the body to another
c) Part of regeneration
d) All of the above
Answer: b

Question: Which of the following are hallucinogens?
a) Charas
b) Bhang
c) Ganja
d) All of these
Answer: d

Question: Cyclosporin is used as
a) Prophylactic for viruses
b) Allergic eczema
c) Immunosuppressant
d) Prophylactic for marasmus
Answer: c

Question: Which of the following endocrine glands is often referred in relation with AIDS?
a) Pancreas
b) Thyroid
c) Adrenal
d) Thymus
Answer: d

Question: The use of antihistamine, adrenaline and steroids quickly reduce the symptoms of
a) Viral disease
b) Helminthes disease
c) Fungal disease
d) Allergy
Answer: d

Question: Hashish and charas are obtained from
a) Papaver somniferum
b) Rauwolfia serpentina
c) Claviceps purpurea
d) Cannabis sativus
Answer: d

Question: Which of the following non-infectious disease is a major cause of death in human beings?
a) Asthma
b) Cirrhosis
c) AIDS
d) Cancer
Answer: d

Question: From which part of Atropa belladonna is the drug “belladona” obtained?
a) Flowers
b) Stems
c) Leaves
d) Dried leaves and roots
Answer: d

Question: Ergot, a drug, is derived from fungus
a) Phytopthora
b) Aspergillus
c) Perenospora
d) Claviceps
Answer: d

Question: Atropine, an alkaloid, is obtained from
a) Hyocyamus niger
b) Datura anoxia
c) Withania somnifera
d) Atropa belladonna
Answer: d

Question: Match the causative organisms with their diseases.

(A) Haemophilus          (1) Malignant influenzae malaria
(B) Entamoeba            (2) Elephantiasis histolytica
(C) Plasmodium           (3) Pneumonia falciparum
(D) Wuchereria            (4) Typhoid bancrofti
(E) Salmonella typhi     (5) Amoebiasis

(a) A – 1, B – 5, C – 3, D – 2, E – 4
(b) A – 3, B – 5, C – 1, D – 2, E – 4
(c) A – 5, B –1, C – 3, D – 4, E – 2
(d) A – 1, B – 3, C – 2, D – 5, E – 4
Answer: b

Statement Type Questions

Question: Which one of the following in not a property of cancerous cells ?
a) They divide in an uncontrolled manner.
b) They show contact inhibition.
c) They compete with normal cells for vital nutrients.
d) They do not remain confined in the area of formation.
Answer: b

Question: Which of the following statement is correct ?
a) Injecting microbes during immunization induces passive immunity.
b) Cell-mediated immune response is responsible for graft rejection.
c) Colostrum during initial days of lactation provides active immunity to infant.
d) None of the above
Answer: b

Question: Sporozoites of the malarial parasite are found in
a) salivary glands of freshly moulted female Anopheles mosquito.
b) saliva of infected female Anopheles mosquito.
c) red blood corpuscles of humans suffering from malaria.
d) spleen of infected humans.
Answer: b

Question: Which of the following statements is correct?
a) Malignant tumours may exhibit metastasis.
b) Patients who have undergone surgery are given cannabinoids to relieve pain.
c) Benign tumours show the property of metastasis.
d) Heroin accelerates body functions.
Answer: a

Question: What is true about T-lymphocytes in mammals ?
a) These are produced in thyroid.
b) These originate in lymphoid tissues.
c) They scavenge damaged cells and cellular debris.
d) There are three main types of T-lymphocytes – cytotoxic T cells, helper T cells and suppressor T cells.
Answer: d

Question: Which one of the following statements is correct with respect to AIDS?
a) The causative HIV retrovirus enters helper T-lymphocytes thus reducing their numbers.
b) The HIV can be transmitted through eating food together with an infected person.
c) Drug addicts are least susceptible to HIV infection.
d) AIDS patients are being fully cured cent per cent with proper care and nutrition.
Answer: a

Question: Select the correct statement with respect to diseases and immunization.
a) Certain protozoans have been used to produce hepatitis B vaccine.
b) Injection of snake antivenom against snake bite is an example of active immunization.
c) If due to some reason B-and T-lymphocytes are damaged, the body will not produce antibodies against a pathogen.
d) Injection of dead / inactivated pathogens causes passive immunity.
Answer: c

Question: Which of the following statement is incorrect?
a) Rheumatoid arthritis is an autoimmune disease.
b) The use of drugs like antihistamine, adrenaline, and steroids quickly reduces the symptoms of bacterial infection.
c) Several genes (called cellular oncogenes) have been identified in normal cells which when activated under certain conditions, could lead to oncogenic transformation of the cells.
d) The vaccine also generates memory – B and T cells that recognize the pathogen quickly on subsequent exposure and overwhelm the invaders with a massive production of antibodies.
Answer: b

Assertion & Reasoning Based

Two statements are given-one labelled Assertion and the other labelled Reason.
Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below.
(a) Both assertion and reason are true and reason is the correct explanation of assertion.
(b) Both assertion and reason are true but reason is not the correct explanation of assertion.
(c) Assertion is true but reason is false.
(d) Assertion is false but reason is true.

Question: Assertion : Some diseases that occurred in childhood do not attack again.
Reason : Memory cells plays an important role.
Answer: a

Question: Assertion : Smack is a by-product of heroin synthesis.
Reason : Heroin is an opium alkaloid.
Answer: b

Question: Assertion : Immunity is the ability of the body to protect-against all type of foreign bodies that enters the body.
Reason : Spleen is the only organ involved in immunity.
Answer: c

Question: Assertion : Cancer patients are given chemotherapeutic treatments.
Reason : Chemotherapeutic agents are used to destroy malignant cells.
Answer: a

Question: Assertion : Mucous membrane are physiological barriers.
Reason : Microorganisms and dust particles entering the respiratory tract are trapped in the mucus.
Answer: d

Question: Assertion : Active immunity is slow and takes time to give its full effective response.
Reason : Injecting the microbes intentionally during immunization or infectious organisms gaining access into body during natural infection induces active immunity.
Answer: c

Question: Assertion: Inspire of exposure to large number of infectious agents humans are resistive to diseases.
Reason: Humans are able to defend against most of the foreign agents due to the ability to fight disease-causing organisms.
Answer: a

Question: Assertion: Artificially acquired passive immunity results when antibodies or lymphocytes produced outside the host are introduced into a host.
Reason: A bone marrow transplant given to a patient with genetic immunodeficiency is an example of artificially acquired passive immunity.
Answer: b

Question: Assertion: IgG is the most abundant class of lgs in the body.
Reason: IgG is mainly found in sweet, tears, saliva, mucus, colostrum and gastro-intestinal secretions.
Answer: d

Very Short Answer Type Questions

Question: What does the enzyme reverse transcriptase catalyze?
Answer : Reverse transcriptase is an enzyme, found mainly in retroviruses, that catalyses the synthesis of DNA from RNA.

Question: How does saliva act in body defence?
Answer : Saliva contains lysozyme which kills the microorganisms that come with food and drink, thus act in body defence.

Question: Name any two infectious diseases that are transmitted through fecal-oral route.
Answer : Poliomyelitis and Shigellosis 

Short Answer Type Questions

Question: Differentiate between benign and malignant tumours.
Answer : Benign tumour does not invade and destroy the tissues in which it originates or spread to distant sites in the body, i.e., a tumour that is not cancerous. Benign tumour may nonetheless cause serious morbidity or mortality by compressing or obstructing vital structures.
Malignant tumour invades and destroys the tissue in which it originates and has the potential to spread to other sites in the body via the blood stream and lymphatic system.

Question: What is metastasis? List any four danger signals of cancer.
Answer : Metastasis is the phenomenon in which cancer cells spread to distant sites through body fluids to develop secondary tumour. This occur by three main routes :
(i) through the blood stream (haematogenous),
(ii) through the lymphatic system,
(iii) across body cavities.
The four danger signals of cancer are :
– A lump or hard area in the breast.
– Unexplained loss of weight and low-grade fever
– An uncurable ulcer.
– Non-injury bleeding from the surface of skin, mouth or any other opening of the body.

Question: Name one plant and the addictive drug extracted from its latex. How does this drug affect the human body?
Answer :  Heroin commonly called smack is chemically diacetylmorphine obtained by acetylation of morphine which is extracted from the latex of poppy plant Papaver somniferum.
It is a depressant and slows down body functions. It induces drowsiness and lethargy. Its after effects include indigestion, reduced vision, decreased weight, sterility and total loss of interest in work.

Question: What is the role of each of the following in the body defences.
(i) Antihistamine
(ii) Plasma cells
(iii) Helper T cells
Answer : (i) Antihistamine is a drug that inhibits the action of histamine in the body by blocking either of two types of receptors for histamine, H₁ or H₂. When stimulated by histamine, H₁ receptors may produce such allergic reactions as hay fever, pruritus (itching), and urticaria (nettle rash).
Antihistamines that block H₁ receptors (H₁-receptor antagonists) are used to relieve these conditions.
(ii) Plasma cells are antibody-producing cells found in blood forming tissues and also in the epithelium of the lungs and gut. They develop in the bone marrow, lymph nodes, and spleen when antigens stimulate B-lymphocytes to produce the precursor cells that give rise to them.
(iii) Helper T cell is a type of T-lymphocyte that plays a key role in cell-mediated immunity by recognizing foreign antigen on the surface of antigen-presenting cells when associated with the individual’s MHC antigens, which is further processed by antigen-presenting cells. Helper T-cell stimulates the production of cytotoxic T-cell, which destroys the target cells.

Long Answer Type Questions

Question: Give the scientific name of the organism that causes whooping cough. Give two main symptoms of this disease. What vaccine gives protection from this disease? 
Answer : Whooping cough or pertussis is caused by Bordetella pertussis and is common childhood disease.
It causes constant cough leaving the child breathless, tired and red in face. Later the voice becomes hoarse and the cough gives a whoop or a loud crowing sound while inhaling. The child usually vomits and there is frothy discharge from his mouth and nose.
Immunisation of the disease is done by DPT vaccination within six weeks of birth.

Question: Describe the asexual and sexual phases of life cycle of Plasmodium that causes malaria in humans.
Answer : Malaria is caused by the toxins produced in the human body by malarial parasite Plasmodium. Life cycle of Plasmodium requires two hosts for completion.
Life cycle of Plasmodium in man (asexual phase): The infective stage of Plasmodium is sporozoite. When the mosquito bites man, sporozoites present in the salivary gland of female Anopheles mosquito are injected into the blood of the man. The parasites initially multiply within the liver cells and then attack the red blood cells (RBCs) resulting in their rupture. The rupture of RBCs is associated with release of a toxic substance, haemozoin, which is responsible for the chill and high fever recurring every three to four days. The released parasites from the ruptured RBCs infect new RBCs and develop into gametocytes (male and female). When a female Anopheles mosquito sucks the blood of an infected human host, it receives RBCs containing gametocytes.
Life cycle of Plasmodium in mosquito: The gametocytes come out of the RBCs into the lumen (cavity) of the stomach of the mosquito. Inside the stomach of the mosquito, the male and female gametocytes fuse (fertilize) to form zygote called oocyst. The nucleus of oocyst divides first by meiosis and subsequently by mitosis, forming large number of small haploid nuclei. At the same time, spindle shaped bodies called sporozoites are formed. When mature oocysts rupture, the sporozoites are liberated into the haemocoel (body cavity filled with blood) of the mosquito. Being motile, the sporozoites move to different organs in the body cavity of the mosquito, but many of them penetrate the salivary glands. The mosquito now becomes infective. When the female Anopheles mosquito bites a healthy person, the sporozoites are injected in his/her blood along with saliva. These sporozoites start the cycle again in human body.