Question

1. the food base of most aquatic ecosystems are

a. worms.
b. phytoplankton.
c. zooplankton.
d. fish.

vocabulary development
in the space provided, write the letter of the term that best matches the description.

1. aquatic organisms that float near the surface of the water a. phytoplankton
2. aquatic organisms that break down dead organisms b. plankton
3. drifting algae c. nekton
4. drifting animals d. benthos
5. aquatic organisms that dwell at the bottom of the water e. decomposers
6. aquatic organisms that are free - swimming f. zooplankton

write “p” on the line in front of each example of plankton, “n” on the line in front of each example of nekton, and “b” on the line in front of each example of benthos.

1. turtles
2. worms
3. zooplankton
4. fish
5. mussels
6. barnacles
7. phytoplankton
8. whales

Explanation:

• Phytoplankton are primary - producers and form the food base of most aquatic ecosystems.
• Plankton are aquatic organisms that float near the water surface.
• Decomposers break down dead organisms.
• Phytoplankton are drifting algae.
• Zooplankton are drifting animals.
• Benthos are aquatic organisms that dwell at the water - bottom.
• Nekton are free - swimming aquatic organisms.

Answer:

1. b. phytoplankton
2. b. plankton
3. e. decomposers
4. a. phytoplankton
5. f. zooplankton
6. d. benthos
7. c. nekton
8. N
9. B
10. P
11. N
12. B
13. B
14. P
15. N