3 General Bio Questions?

Question

1) Turnover bring nutrient rich waters into the photic zone. Which of the following would initially and directly benefit from this process:
a) rotifers
b) custacean zooplankton
c) filter feeding molluscs
d) carnivorous fish
e) diatoms

2) The water attaining its greatest density drives movement of nutrient rich water in which of the following experiments:
a) temperature lake that forms a ternocline in the summer
b) tropical lake that forms a termocline
c) open ocean far from the coast of the continents
d) equatorial water
e) coastal regions where the marine currents flow off shore

3. Which of the following is NOT in short supply in the marine waters of the photic zone during the summer in at latitudes of 60 N:
a) nitrate
b) phosphate
c) silicate
d) dissolved carbon dioxide
e) the major inorganic component of a diatom cell covering

Please provide some explanations too if you don't mind. Thanks a lot!! :)

Answer 1

1. E diatoms. Diatoms are the only producers/autotrophs among your choices. They take up nutrients from the water. The rest are consumers/heterotrophs. They get their nutrients from producers, so they will not use the nutrients from the water directly like the diatoms will.