Question

1) Cytotoxic T cells can attack target cells with which of these chemical weapons?  

A) secrete free radicals

B) secrete organic solvenT

C) secrete mutant proteins

D) secrete a cytokine that triggers apoptosis

2) T cells and B cells can be activated only by

A) pathogens.

B) interleukins, interferons, and colony-stimulating factors.

C) cells infected with viruses, bacteria, or cancer cells.

D) exposure to a specific antigen at a specific site in a plasma membrane.

3) The purpose of circular folds, villi and microvilli in the small intestine is to

A) allow for stretching of the intestine as food passes through

B) increase surface area for absorption

  C) secrete digestive hormones

D) secrete digestive enzymes

Answer 1

1. A) secrete free radicals

Explanation: Cytotoxic T cells attack the target cells by releasing the free radicles that causes injury to the membrane of the target cells.

2. D) exposure to a specific antigen at a specific site in a plasma membrane

Explanation: T cells and B cells are the cells of adaptive immunity which is specific immunity. It is activated when there is exposure to the specific antigen.

3. B) increase surface area for absorption

Explanation: the function of the villi and microvilli are to increase the surface area for the absorption.