Question

How much of the oxygen we breathe is produced by pytoplankton?

20%, 35%, 50%, 7%

I think the answer is 50%. Am I correct.

All of the following are adaptations some phytoplankton have for floating except?

1) Cells have large cavity in the center
2) spines
3) reducing surface area
4)stores of oil and fat

I think the answer is number 4. Am I correct?

Answer 1

I hope so, that's what I'm putting.

Answer 2

One of the benefits of phytoplankton is that it removes excess carbon dioxide from the atmosphere. What human activities contribute the most to increasing carbon dioxide levels?