Evolution Unit quiz

How does the body recognize "self" cells compared to "nonself" cells?

"Self" cells are marked by glycoproteins called major-histocompatibility complexes (MHCs).

__________ has the ability to target cells of the body that are infected with pathogens, while also responding to any pathogens that are free in the blood or interstitial fluid of the body.

Adaptive immunity

True or False: In order to generate active immunity, individuals must be exposed to the actual pathogen itself. This is why vaccinations always contain live pathogens.

False

Which of the following statements about components of the flu vaccine and their intended function is true?

Formaldehyde is used to inactivate toxins from the virus or bacteria that may have been present during production.

A bilingual couple can speak English and Spanish. They have a child that is also bilingual and can speak English and Spanish. Has evolution occurred?

No

Once in the respiratory tract, the flu virus targets cells based on specific glycoproteins on their surfaces. How does the virus gain entry into the target cell?

The N spikes of the influenza virus help break down the plasma membrane of a cell, allowing entry of the virus into the cell.

Why are new flu vaccinations required for each new flu season?

The flu virus mutates frequently enough that last year's vaccination will no longer target currently circulating flu strains.

What is the correct sequence of events in viral reproduction?

attachment, penetration, biosynthesis, maturation and release

A certain species of a butterfly varies in color from white to dark blue. The birds found in the same area feed on the white or lightly colored butterflies, leaving butterflies that are darkly colored. This is an example of what type of selection?

directional selection

When the influenza virus enters into an epithelial cell within the respiratory tract, the infected cell responds by

posting antigens on its cell surface, acting as a flag for the cytotoxic T cells to destroy it.