AP Bio Chapter 7

Question 0

The presence of cholesterol in the plasma membranes of some animals

Answer 0

Enables the membrane to stay fluid more easily when cell temperature drops

Question 1

Which types of molecules are the major structural components of the cell membrane?

Answer 1

Phospholipids and proteins

Question 2

What kinds of molecules pass through a cell membrane most easily?

Answer 2

Small and hydrophobic. Phospholipids + some proteins can move laterally along the membrane rapidly

Question 3

It is a passive process in which molecules move from a region of higher concentration to a region of lower concentration.

Answer 3

Diffusion

Question 4

Water passes quickly through cell membranes because?

Answer 4

It moves through aquaporins in the membrane

Question 5

Celery stalks that are immersed in fresh water for several hours become stiff and hard. Similar stalks left in a 0.15 M salt solution become limp and soft. From this we can deduce that the cells of the celery stalks are what?

Answer 5

Hypertonic to fresh water but hypotonic to the salt solution

Question 6

Mammalian blood contains the equivalent of 0.15 M NaCl. Seawater contains the equivalent of 0.45 M NaCl. What will happen if red blood cells are transferred to seawater?

Answer 6

Water will leave the cells, causing them to shrivel and collapse.

Question 7

White blood cells engulf bacteria through what process?

Answer 7

Phagocytosis