NEET Biology Human Health and Disease MCQs Set 17

Answer: (c) interferon

Explanation:
1. Interferons are glycoproteins produced by viral infected cell.
2. They make the cells resistant to viral infection.
3. Hence option (c) is correct: interferon

Teacher's Note:
1. Disease questions test the causative organism, vector and symptom, so tabulate them.
2. For drugs, remember the plant source and the effect on the nervous system.

Answer: (a) virus

Explanation:
1. Influenza is caused by virus Myxovirus influenzae.
2. It is an acute respiratory tract infection.
3. Hence option (a) is correct: virus

Teacher's Note:
1. Disease questions test the causative organism, vector and symptom, so tabulate them.
2. For drugs, remember the plant source and the effect on the nervous system.

Answer: (d) salivary glands of mosquito

Explanation:
1. Sporogony of Plasmodium occurs in the salivary glands of female Anopheles.
2. Hence option (d) is correct: salivary glands of mosquito

Teacher's Note:
1. Disease questions test the causative organism, vector and symptom, so tabulate them.
2. For drugs, remember the plant source and the effect on the nervous system.

Answer: (a) ss RNA

Explanation:
1. HIV (AIDS virus) consists of glycoprotein coat, double layer of lipid membrane of two protein coats.
2. It contains ss RNA and reverse transcriptase.
3. Hence option (a) is correct: ss RNA

Teacher's Note:
1. Disease questions test the causative organism, vector and symptom, so tabulate them.
2. For drugs, remember the plant source and the effect on the nervous system.

Answer: (d) IgM & IgG

Explanation:
1. Foreign cells are lysed by the antibody-complement system.
2. IgM and IgG are the antibodies that activate complement and cause lysis.
3. IgE is involved in allergic responses and IgA is found in secretions.
4. Hence option (d) is correct: IgM & IgG

Teacher's Note:
1. IgE immunoglobulin acts as mediator in allergic response.
2. Disease questions test the causative organism, vector and symptom, so tabulate them.

Answer: (d) Valium

Explanation:
1. Valium is the anti depressant used by addicts that produces feelings of calmness, relaxation and drowsiness.
2. Hence option (d) is correct: Valium

Teacher's Note:
1. For drugs, remember the plant source and the effect on the nervous system.
2. Disease questions test the causative organism, vector and symptom, so tabulate them.

Answer: (d) Papaver somniferum

Explanation:
1. Opium is a narcotic formed from the latex released by lacerating the immature seed pods of opium poppies (Papaver somniferum).
2. Morphine is the most preva- lent alkaloid in opium, about 10%-16% of the total alkaloids.
3. Hence option (d) is correct: Papaver somniferum

Teacher's Note:
1. It is responsible for most of the harmful effects such as lung edema, respiratory difficulties, coma, or cardiac or respiratory collapse.
2. For drugs, remember the plant source and the effect on the nervous system.

Answer: (b) ELISA

Explanation:
1. The ELISA is a fundamental tool of clinical immunology, and is used as an initial screen for HIV detection.
2. Based on the principle of antigen- antibody interaction, this test allows for easy visualization of results.
3. Hence option (b) is correct: ELISA

Teacher's Note:
1. For drugs, remember the plant source and the effect on the nervous system.
2. Disease questions test the causative organism, vector and symptom, so tabulate them.

Answer: (c) Assertion is true but the Reason is false.

Explanation:
1. Male Anopheles mosquito do not have piercing and sucking type of mouth parts.
2. So, they can not inject malarial parasite into man.
3. Hence option (c) is correct: Assertion is true but the Reason is false.

Teacher's Note:
1. For drugs, remember the plant source and the effect on the nervous system.
2. Disease questions test the causative organism, vector and symptom, so tabulate them.

Answer: (c) Assertion is true but the Reason is false.

Explanation:
1. Rabies (hydrophobia) is caused by rabies virus.
2. Its vectors are raboid animals especially dogs.
3. Hence option (c) is correct: Assertion is true but the Reason is false.

Teacher's Note:
1. It leads to encephalitis, fear of water (hydrophobia), high fever, severe headache, spasm of throat & chest, leading to death.
2. Disease questions test the causative organism, vector and symptom, so tabulate them.

Answer: (a) Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Explanation:
1. Histamine is produced by mast cells in response to the allergy and inflammatory reaction.
2. When histamine is released from mast cells, it causes vasodilation and an increase in permeability of the blood vessel walls.
3. Hence option (a) is correct: Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Teacher's Note:
1. These effects, in turn cause the common symptoms of allergy including a running nose and watering eyes.
2. Disease questions test the causative organism, vector and symptom, so tabulate them.

Answer: (b) Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Explanation:
1. Diarrhoeal disease conditions include frequent and excessive discharge of watery material from the bowel.
2. Such diseases mostly result from ingestion of harmful germs with food and water.
3. Hence option (b) is correct: Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Teacher's Note:
1. E. coli, Shigella sp. & salmonella sp. causes diarrhoea.
2. Diarrhoea caused by virus, bacteria or parasites possesses two characteristics- firstly, the offending organisms colonise the intestine and as a consequence cause inflammation of the intestine or enteritis; and secondly, they upset the balance of intestinal fluid absorption and secretion mechanism, often enhancing the latter very considerably, which is then manifested as watery stool discharged frequently in large volumes.

Answer: (d) Both Assertion and Reason are false.

Explanation:
1. Blood alcohol test measures the amount of alcohol (ethanol) in the body.
2. Alcohol is quickly absorbed into the blood and can be measured within minutes of having an alcoholic drink.
3. Hence option (d) is correct: Both Assertion and Reason are false.

Teacher's Note:
1. The amount of alcohol in the blood reaches its highest level about an hour after drinking.
2. But food in the stomach may increase the amount of time it takes for the blood alcohol to reach its highest level.

Answer: (d) Both Assertion and Reason are false.

Explanation:
1. Interferons are natural proteins produced by the cells of the immune system in response to challenges by foreign agents such as viruses, parasites and tumor cells.
2. Interferons belong to the large class of glycoproteins known as cytokines.
3. Hence option (d) is correct: Both Assertion and Reason are false.

Teacher's Note:
1. Interferons are produced by a wide variety of cells in response to the presence of double-stranded RNA, a key indicator of viral infection.
2. Interferons assist the immune response by inhibiting viral replication within host cells, activating natural killer cells and macrophages, increasing antigen presentation to lymphocytes, and inducing the resistance of host cells to viral infection.

Answer: (a) Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Explanation:
1. Oncoviruses are cancer – causing viruses and may be DNA or RNA virus e.g., Epstein – Barr – Virus, Herpes simplex type 2 virus etc.
2. This shows that the development of cancerous tumour is associated with certain genes.
3. Hence option (a) is correct: Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Teacher's Note:
1. Disease questions test the causative organism, vector and symptom, so tabulate them.
2. For drugs, remember the plant source and the effect on the nervous system.

Answer: (a) Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Explanation:
1. Usually, person shows symptoms of HIV infection within 2 to 6 weeks of exposure to the virus.
2. But in some persons, the virus may remain silent for long periods (upto 10 years) before symptoms of full blown AIDS are observable.
3. Hence option (a) is correct: Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Teacher's Note:
1. The symptoms of HIV infection include fever, lethargy, pharyngitis, nausea, headache, rashes etc.
2. Persons suffering from AIDS have a weakened immune system due to depletion of T- helper cells.

Answer: (c) Assertion is true but the Reason is false.

Explanation:
1. Interferons are proteins that are effective against most viruses.
2. They are naturally produced by virus infected cells.
3. Hence option (c) is correct: Assertion is true but the Reason is false.

Teacher's Note:
1. The proteins interact with adjacent cells and make them resistant to virus attack.
2. Now interferons are also being manufactured through genetic engineering.

Answer: (b) Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Explanation:
1. Cancer cells divide and redivide mitotically and is due to the activation of pro- oncogenes.
2. Hence option (b) is correct: Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Teacher's Note:
1. For drugs, remember the plant source and the effect on the nervous system.
2. Disease questions test the causative organism, vector and symptom, so tabulate them.

Answer: (b) Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Explanation:
1. Artificially acquired passive immunity results when antibodies or lymphocytes that have been produced outside the host are introduced into a host.
2. This type of immunity is immediate short lived, lasting only a few weeks to a few months.
3. Hence option (b) is correct: Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Teacher's Note:
1. An example is bone marrow transplant given to a patient with genetic immunodeficiency.
2. Strategies for Enhancement in Food Production 31.

Answer: (c) Assertion is true but the Reason is false.

Explanation:
1. Plasmodium vivax causes malaria, so the Assertion is true.
2. Malaria is transmitted by the bite of the female Anopheles mosquito, not by polluted water, so the Reason is false.
3. Hence option (c) is correct: Assertion is true but the Reason is false.

Teacher's Note:
1. Malaria is caused by Plasmodium whose sexual phase occurs in the mosquito Anopheles.
2. When female Anopheles feed on blood, they can serve as vector host for malarial parasite.