I have some questions on biology?

Question

1. Nitrogen is avaiblabe to plant only in the form of...
a) ammonium
b) nitrite
c) both
I eliminated some answers but these are the 3 choices I can't decide on

2. Which statement is true?
a) An ecosystem's trophic structure determines the rate at which energy cycles within a system
b) It is impossible for consumers to outnumber producers in an ecosystem
c) Chemoautotrophic bacteria near deep-sea vents are independent of solar energy
I don't think it's b... it might be c but I'm not sure

3. Which can be primary producers
A) cyanobacteria
B) zooplankton
C) flowering plants
D) only A and C are correct

Thanks!

Answer 1

1. C
2. C is definitely true, but B is tricky. B can be false, though because one big tree can be outnumbered by insects feeding on it. The question says outnumbered, not out-biomassed.
3. D Cyanobacteria used to be called blue-green algae.

Answer 2

1. None of the above, although C is the closest.
Plants can absorb nitrate in addition to ammonia and nitrite.

2. C is the best answer.
I considered B, but the question doesn't say it has to be a BALANCED ecosystem. LOL.

3. D
The question is basically asking which are autotrophs.

Answer 3

im pretty sure that #2 is C. Other than that i have no idea. Good luck getting the answers