The plasma membrane is the protective barrier that separates living organisms from their environment. What does the term selectively permeable mean?
Allowing some substances to pass more easily than others.
B. Allowing all substances to cross easily.
C. Not allowing substances to cross the membrane.
D. Allowing solids but not liquids to pass through easily.
查看答案
Which process does the cell use to change the composition of the cell membrane?
A. osmosis
B. endocytosis
C. exocytosis
D. active transport
Endocytosis is the process of _____ and exocytosis is the process of _____.
A. bringing nutrients into the cell, removing excess water from the cell
B. bringing nutrient into the cell, shipping substance out of the cell
C. sending materials out of the cell, removing excess water from the cell
D. sending materials out of the cell, bringing nuterients into the cell.
If a plant cell had a ΨP = 0.3 bars and ΨS = -0.45 bars and was placed in an open beaker of water with a solution of 0.03 M NaCl at 25 degrees Celsius, which way will water move?
A. Water will move out of the cell because the cell has a greater water potential than the beaker.
B. Water will move into the cell because the cell has a lower water potential than the beaker.
C. The water potentials are equal, there will be no net movement.
D. Water will move out of the cell because the cell has a lower water potential than the beaker.
A dialysis bag that has a concentration of 0.02 M glucose and 0.1 M starch is placed in a beaker of water containing 0.03 M glucose. Glucose can pass through the dialysis tubing and starch cannot. Which describes the movement of molecules?
A. Water and glucose move out of the bag and into the beaker.
B. Water moves out of the bag and glucose moves into the bag.
C. Water and glucose move into the bag.
D. Water moves out of the bag and glucose moves into the beaker.
微信支付 
支付宝支付