Question

unit 3 review

1. what is the process by which living organisms maintain their internal environment?
2. a plant cell performing photosynthesis should have a relatively high internal concentration of

_______ molecules.
a. carbon dioxide
b. glucose
c. light
d. water

1. diffusion occurs when particles move from areas of _______ concentration to areas of

_____ concentration. this is called \moving _____\ the concentration gradient.
image of particles on left and right sides

1. describe the movement of particles between the left and right sides in the situation shown above:
2. write the abbreviations under the statements that describe them.

active transport = at facilitated diffusion = fd simple diffusion = sd
a. goes with concentration gradient
b. requires energy
c. requires transport protein
d. describes small, nonpolar molecules moving between lipids

Explanation:

1. The process of maintaining internal stability is a core biological concept.
2. Photosynthesis produces glucose, so active cells accumulate it.
3. Diffusion follows concentration gradient direction.
4. Particles move from higher to lower concentration (left to right).
5. Match transport types to their key traits: SD/FD follow gradient; AT needs energy; FD needs proteins; SD is for small nonpolar molecules.

Answer:

1. Homeostasis
2. b. Glucose
3. high; low; down
4. Particles move from the left (higher concentration) to the right (lower concentration) down the concentration gradient.
5. A. SD, FD

B. AT
C. FD
D. SD