Zoology MCQs for NEET — Practice Questions with Answers

The correct matches for the diseases and their causative agents are: Cold - Rhino Virus (P-i), Pneumonia - Halmophilus Influenza (Q-iv), AIDS - HIV (R-ii), and Typhoid - Salmonella typhi (S-iii). Hence, option o3 correctly matches the columns.

Let's match the columns:

Cellular Barrier (P): This involves certain types of leucocytes which help in protecting the body from pathogens.

Physiological Barrier (Q): Tears from the eyes act as a physiological barrier by washing away microbes.

Physical Barrier (R): The epithelial lining in the urogenital tract acts as a physical barrier to prevent the entry of pathogens.

Cytokine Barrier (S): Virus-infected cells produce cytokines to inhibit the spread of the virus.

Thus, the correct match is: P - iii, Q - i, R - ii, S - iv.

The flowering branch shown in the image is of the plant Cannabis sativa. This plant is known for producing hallucinogenic compounds such as THC (tetrahydrocannabinol).

Hence, the correct answer is Hallucinogen.

Assertion (A): Macrophages act as a factory of HIV because they are one of the primary cells that HIV infects and uses to replicate.

Reason (R): Macrophages continuously produce molecules of HIV, aiding in the persistence and spread of the virus within the host.

Thus, both A and R are correct, and R is the explanation for A. Hence, the correct option is: A & R both are right & R is explanation of A.

Typhoid fever is caused by the bacterium Salmonella typhi. It spreads through contaminated food and water. The correct answer is Salmonella.

Leukemia is a type of cancer that affects the blood and bone marrow, characterized by an abnormal increase in white blood cells. The correct answer is Leukemia.

HIV primarily targets and decreases the number of Helper T-Cells (CD4 cells) in the body, weakening the immune system. The correct answer is Helper T-Cells.

An antigen is a molecule capable of inducing an immune response in the host organism. It is recognized by the immune system as a foreign entity, leading to the production of antibodies and activation of immune cells.

Histamine is a substance produced by mast cells and is responsible for the symptoms of an allergic reaction. It causes dilation of blood vessels and makes the vessel walls abnormally permeable, leading to inflammation and other allergic symptoms.