chapter 43 immune systemmm

Which secretion is not a barrier that prevents pathogens from entering the body?

Ear wax.

Antigens.

Mucus.

Lysozyme.

Antigens

Which of the following cells can engulf a pathogen?

Macrophages.

Mast cells.

Platelets.

Cytokines.

Macrophages.

whats the purpose of the inflammatory response

to isolate any invaders at the site of the wound and to repair any tissue damage that may have occurred.    

Which of the following statements best describes the role of mast cells in the inflammatory response?

They secrete substances that degrade bacterial cell walls and engulf and digest the invaders.

They release cytokines to stimulate the release of additional neutrophils and macrophages.

They release chemicals that constrict blood vessels at some distance from the wound site.

They release chemicals that dilate blood vessels near the wound site, allowing blood components to enter the region from the bloodstream.

They release chemicals that dilate blood vessels near the wound site, allowing blood components to enter the region from the bloodstream.

Which of the following events occurs first when a wound that breaks the skin has occurred?

Macrophages present bacterial proteins as antigens on their plasma membrane.

Mast cells secrete chemical messengers to regulate blood flow to the wound.

Neutrophils secrete substances that degrade bacterial cell walls.

Platelets release proteins that form clots and decrease bleeding.

Platelets release proteins that form clots and decrease bleeding.

An antigen

is just a molecule (often a protein) on a pathogen that triggers an immune response.

Memory cells

persist for years (sometimes a lifetime), allowing for a faster, stronger secondary immune response.

Plasma cells

produce antibodies,not memory cells.

The genetic material of HIV consists of _____.

double-stranded RNA

single-stranded DNA

double-stranded DNA

single-stranded RNA

none of the above

single-stranded RNA

What is the function of reverse transcriptase?

catalyzing the formation of a polypeptide from a RNA template

catalyzing the formation of RNA from a polypeptide template

catalyzing the formation of DNA from a RNA template

catalyzing the formation of RNA from a DNA template

catalyzing the formation of DNA from a polypeptide template

catalyzing the formation of DNA from an RNA template

What is the source of a viral envelope?

provirus

host cell DNA

viral glycoproteins

prophages

host cell membrane

host cell membrane

Double-stranded viral DNA is incorporated into a host cell as a _____.

provirus

promoter

homeoboxes

transposon

lac

provirus

What is the final step in the cell-mediated response to a viral infection?

Cytotoxic T lymphocytes punch holes in the membranes of infected host cells.

How do cells involved in the humoral response respond to antigen presentation on the surface of a B cell?

Helper T cells recognize the receptor-antigen complex and cause plasma and memory cells to be produced to then produce antibodies.

Which protein presents viral antigens on the outer surface of cells?

MHC protein

How are cytotoxic T lymphocytes (CTLs) produced?

CD8+ T cells divide and differentiate into cytotoxic T lymphocytes.