If a person has a genetic defect in the metabolic pathway that produces cytokines, then

a. macrophages won't be produced by the immune system.
b. b cells wouldn't be activated to respond when cells presenting antigens are present.
c. histamine won't be produced by mast cells.
d. t cells would take over the role of activating b cells.

Option B

Explanation:

Immune system of human beings responds to the antigen specifically and non specifically.

Non specific response consists of some physical and chemical barriers but in case of specific response, antibodies are produced specifically for the antibodies.

The T- cell and B- cells of the body works by coordinating between them, so if T-cell will not tend to produce cytokines, then B-cells of the body would not present antigens, as they work in coordination.

So, the correct answer is option B

the menstrual cycle – higher tier. negative feedback mechanisms affect the production of hormones in the menstrual cycle. oestrogen also stimulates the release of lh (luteinising hormone) from the pituitary gland, which in turn controls the production of progesterone.