Question

1.) 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?

Multiple Choice

a.)Glycoproteins within the virus structure bind with glycoproteins on the membrane of the target cell and the virus squeezes through the glycoprotein into the cell.

b.)Viruses are made up of lipids and can therefore diffuse through the membrane of target cells, gaining entry.

c.)The H spikes of the influenza virus break down the cell wall, allowing the virus to gain entry.

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

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2.) About 12,000 years ago, a mass extinction event occurred and 75% of the world’s large mammal species were eliminated. While a small number of cheetahs managed to survive and restore the world’s population of cheetahs, this event caused an extreme reduction of the cheetah’s genetic diversity. Based on the principles of natural selection, which of the following is a consequence of their reduced genetic diversity?

Multiple Choice

a.)Cheetahs within the same population do not vary in their reproductive success.

b.)Cheetahs have never fully adapted to the current environment.

c.)Cheetahs have very little heritable variation, which will make it difficult for them to adapt as the environment changes.

d.)Cheetahs are unable to effectively compete with each other for resources.
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3.) Which kind of T cell is most important in the removal of virally-infected cells from the body?

Multiple Choice

a.) cytotoxic T cells

b.) suppressor T cells

c.) memory T cells

d.) helper T cells

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4.) Darwin was very interested in the observation that animals on distant and isolated landmasses appeared to be related to animals on the mainlands. However, despite their similar appearance, the animals were indeed not related. Which of the following types of evidence would help Darwin make sense of his observations?

Multiple Choice

a.)fossil

b.)biogeographical

c.)anatomical

d.)biochemical

Answer 1

1.a.)Glycoproteins within the virus structure bind with glycoproteins on the membrane of the target cell and the virus squeezes through the glycoprotein into the cell.

Viruses attach to receptors present on the cell surface to enter in to any cell.

2.

variations in a population help in evolution. No variations, population may suffer the danger of extiction.

3.

a. Cytotoxic T cells.

It is these cells which kill the cells in which viruses are present. Cytotoxic T cells also destory cancer cells and cells of transplanted organs.

4.

b. Biogeographical evidence.

The animals of far off places are similar in appearance because they inhabit the similar type of habitats. Conditions in the habitat are similar. It is also called adaptive radiation.