List of top Biology Questions on human health and disease asked in CBSE CLASS XII

Read the following passage and answer the questions that follow. Prevention is the frontline response to drug use. Effective interventions address the underlying conditions contributing to drug use, such as a lack of connection to family or community, instability, insecurity, trauma, mental health issues, etc. When addressed, these factors can effectively prevent the initiation of drug use and the progression to drug use disorders. Study the few key figures of drug use given below and answer the questions that follow.

(a) What do you infer from the figures in Table No. 1 about the people with drug use disorders, 2022 (in million)? State any two of your observations.

(b) How are Hepatitis C and HIV related to drug use disorders by people, as shown in Table No. 2? State the correlation between the two.

(c)

[(i)] Give the scientific name of (p) shown in Table No. 1.
OR
[(ii)] Give the scientific name of (q) shown in Table No. 1.

Assertion (A): In humans, filariasis is characterized by inflammation in the lower limbs.
Reason (R): Filarial worm usually lives in the lymphatic vessels of the lower limbs.

A characteristic property that distinguishes a malignant tumor from a benign tumor is:

Immunity in our body is of two types: (i) Innate immunity and (ii) acquired immunity. Innate immunity is a non-specific defence mechanism, whereas acquired immunity is pathogen-specific; it is called specific immunity too. Acquired immunity is characterised by memory. Antibodies are specific to antigens and there are different types of antibodies produced in our body: they are IgA, IgE, IgG and IgM. It shows primary response when it encounters the pathogen for the first time and secondary response during the subsequent encounters with the same Antigen/Pathogen.
(a) Name the two types of specialised cells which carry out the primary and secondary immune response.
(b) Why is the antibody-mediated immunity also called as humoral immune response?
Attempt either sub-part (c) or (d):
(c) The organ transplants are often rejected if taken from suitable compatible persons.
(i) Mention the characteristic of our immune system that is responsible for the graft rejection.
(ii) Name the type of immune response and the cell involved in it.
OR
(d) How is active immunity different from passive immunity?

Samples of blood and urine of a sportsperson are collected before any sports event for drug tests.
(a) Why there is a need to conduct such tests?
(b) Name the drugs the authorities usually look for.
(c) Write the generic names of two plants from which these drugs are obtained.

Student to attempt either option (A) or (B).
(A) Describe any two situations where a medical doctor would recommend injection of pre-formed antibodies (antitoxins) into the body of a patient.
OR
(B) The symptoms of malaria do not appear immediately after the entry of sporozoites into the human body when bitten by female Anopheles mosquito. Explain why it happens.

The decrease in the T-Lymphocytes count in human blood will finally result in

Assertion (A): Streptococcus pneumoniae and Haemophilus influenzae are responsible for causing infectious disease in human beings.
Reason (R): A healthy person acquires the infection by inhaling the aerosols released by an infected person.

Allergy in humans is a result of release of the following chemicals from the mast cells:

Student to attempt either option (A) or (B):
(A) Explain how the immunity of a person is affected if there is atrophy (degeneration) of the thymus gland at an early stage of life.
OR
(B) (i) What are interferons? Explain their role in providing immunity to a person.
(ii) Which category of innate immunity defence barrier can interferons be classified into?

Early detection of HIV in suspected AIDS patients can be done using the diagnostic technique of:

The type of antibodies produced during an immune response to allergens as dust and pollen grains in a person is:

Explain how the immunity of a person is affected if there is atrophy (degeneration) of the thymus gland at an early stage of life.

Read the following passage and answer the questions that follow.

Deaths related to the use of drugs were estimated at about 5,00,000 in 2019, 17.5 percent more than in 2009. Liver diseases attributed to Hepatitis B are a major cause of drug-related deaths, according to UNODC, accounting for more than half of the total number of deaths attributed to the use of drugs. Drug overdoses account for a quarter of drug-related deaths.

Opioids contribute to account for the most severe drug-related harm, including fatal overdoses, when used non-medically. At the global level, two-thirds of direct drug-related deaths are due to opioids, and in some sub-regions the proportion can be as high as three-quarters of such deaths.

(a) Why are people taking opioids more prone to liver diseases attributed to Hepatitis B?

(b) What is meant by direct drug-related disease?

(c) (i) What is the scientific name of the plant from which the opioids are derived and from which part of the plant is it extracted?

OR

(c) (ii) State two common warning signs of drug abuse among the youth.

(i)What are interferons? Explain their role in providing immunity to a person.
(ii) Which category of innate immunity defence barrier can interferons be classified into?

Assertion (A): A person infected with malaria suffers from chill and high fever, recurring every three or four days.
Reason (R): The parasite attacks the RBC resulting in their rupture and release of haemozoin.

In which of the following human diseases does the body's self-defence mechanism attack self-cells?

Assertion (A): While working on Staphylococci, Alexander Fleming observed that Penicillium notatum inhibits the growth of bacteria.
Reason (R): The inhibiting chemical was commercially extracted and its full potential was established by Alexander Fleming.

Colostrum secreted by the mother’s mammary glands in a human female during the initial days of lactation is rich in antibody:

Give an account of the generalised structure of an antibody molecule produced by B-lymphocytes in response to the pathogen.

Other than public awareness and counselling, enlist four measures taken up by NACO, WHO and other NGOs to prevent the spread of HIV infection in the society.