Unit 1: Transport Across Cell Membranes From SQA CS

Question 1

A

Answer 1

The cell membrane consists of phospholipids and proteins and is selectively
permeable.

Question 2

B

Answer 2

Passive transport occurs down a concentration gradient and does not require
energy. Examples of passive transport are diffusion and osmosis.

Question 3

C

Answer 3

Diffusion is the movement of molecules down a concentration gradient from a
higher to a lower concentration.

Question 4

D

Answer 4

Osmosis is the movement of water molecules from a higher water concentration to
a lower water concentration through a selectively permeable membrane.

Question 5

E

Answer 5

Animal cells can burst or shrink and plant cells can become turgid or plasmolysed.
Relationship between different concentrations of solutions and their effect on cells.

Question 6

F

Answer 6

Active transport requires energy for membrane proteins to move molecules and
ions against the concentration gradient.