Question

question 8
water moves via osmosis
from an area with a high concentration of water to one of lower concentration
from an area with a low concentration of water to higher concentration
from an area with a high concentration of other solutes to a lower one

question 9
which characteristic of a phospholipid contributes to the fluidity of the membrane?
the head
a saturated fatty acid tail
double bonds in the fatty acid tail
cholesterol content

question 10
red blood cells placed in distilled water will _______________.
shrink as proteins move out of the cell by diffusion
swell as water moves into the cells by active transport
shrink as sodium moves out of the cells by diffusion
remain unchanged because of homeostatic mechanisms
swell as water moves into the cells by osmosis

Explanation:

• Question 8: Osmosis is the movement of water from an area of high - water concentration to an area of low - water concentration. This is due to the principle of diffusion to equalize concentration.
• Question 9: Double bonds in the fatty acid tail of a phospholipid introduce kinks, preventing the phospholipids from packing tightly together, thus contributing to membrane fluidity. Saturated fatty acid tails allow for tight packing and reduce fluidity, the head is polar and not related to fluidity in this context, and cholesterol has a more complex role in regulating fluidity rather than being the main contributor to the basic fluid - like nature provided by double bonds.
• Question 10: Distilled water is hypotonic to red blood cells. Water moves into the cells by osmosis (a passive process, not active transport), causing the cells to swell. Proteins and sodium movement are not the main factors here, and homeostatic mechanisms cannot prevent the osmotic influx of water in this extreme case.

Answer:

Question 8: from an area with a high concentration of water to one of lower concentration
Question 9: Double bonds in the fatty acid tail
Question 10: swell as water moves into the cells by osmosis