Cancer (NCERT) - Free MCQ Practice Test with solutions, NEET Biology

Fetus receiving antibodies from mother through placenta is an example of passive immunity.

NCERT Topic: Active and passive immunity

NCERT Line: The yellowish fluid colostrum secreted by mother during the initial days of lactation has abundant antibodies (IgA) to protect the infant. The foetus also receives some antibodies from their mother, through the placenta during pregnancy. These are some examples of passive immunity.

    A: A−(iv), B−(i), C−(v), D−(iii), E−(ii)

B: A−(ii), B−(i), C−(v), D−(iii), E−(iv)

C: A−(iv), B−(v), C−(iii), D−(ii), E−(i)

D: A−(ii), B−(v), C−(iii), D−(i), E−(iv)

Allergy: Linked to IgE, which is responsible for allergic reactions.

Helper T-cells: Linked to activation of B-cells, crucial for immune response.

AIDS virus: HIV is a single-stranded RNA virus.

X-rays: Known carcinogens that can cause cancer.

Treatment of cancer: Often involves immunotherapy.

The correct option is: A: A−(iv), B−(i), C−(v), D−(iii), E−(ii)

Correct option: C

Reason: Statement (iii) in the table is incorrect because the life span assignments are reversed. Normal somatic cells have a definite life span, while many cancer cells acquire mechanisms that allow an indefinite or greatly extended life span.

Normal cells undergo replicative senescence largely due to progressive shortening of telomeres after repeated divisions. Cancer cells commonly reactivate or upregulate telomerase or use alternative lengthening mechanisms, which helps them escape senescence and attain an effectively indefinite proliferative potential.

The other listed differences are correctly stated: (i) normal cells typically undergo both cell division and differentiation, whereas cancer cells often show loss of normal differentiation (anaplasia); (ii) normal cells display contact inhibition, which is lost in cancer cells; and (iv) normal cells divide in a controlled manner while cancer cells divide in an uncontrolled manner. Therefore only statement (iii) is wrong as presented, so option C is correct.

Sarcoma is a cancer of connective tissues and muscular tissues. Fibroblasts are the cells present in the connective tissue that act as precursors of collagen, elastic and reticular fibres.