Question

multiple choice 1 point
in order to function properly and stay alive, cells must maintain a relatively constant internal environment (homeostasis). the plasma membrane helps
the cell maintain homeostasis. the membrane is mostly made up of lipids and proteins, and it is selectively permeable. which statements are true
regarding the cell membrane’s role in homeostasis?
a. if there is an excess of carbon dioxide inside the cell, some of the carbon dioxide molecules permeate the membrane and leave the cell.
b. if there is a higher solute concentration inside the cell and a lower solute concentration outside the cell, water will diffuse from the inside to
the outside of the cell.
c. passive forms of transport move molecules such as water across the cell membrane with no energy added.
d. molecules, such as oxygen gas, diffuse across the membrane along a concentration gradient, with molecules diffusing from a lower
concentration to a higher concentration.
e. both a and b are true
f. both a and c are true

Explanation:

• Analyze Option A: Carbon dioxide is a small molecule and can pass through the cell membrane (selectively permeable). If there's excess inside the cell, it will move out (down its concentration gradient) to maintain homeostasis. So A is true.
• Analyze Option B: Water moves by osmosis from an area of lower solute concentration (higher water concentration) to higher solute concentration (lower water concentration). If inside has higher solute, water should move into the cell, not out. So B is false.
• Analyze Option C: Passive transport (like diffusion, osmosis) moves molecules without energy input, using concentration gradients. So C is true.
• Analyze Option D: Diffusion is from higher to lower concentration, not lower to higher. So D is false.
• Analyze E: B is false, so E is false.
• Analyze F: A and C are both true, so F is correct.

Answer:

F. Both A and C are true