Light & The Aquatic Environment

Question 1

What’s the photic zone?

Answer 1

Upmost layer of the water body that receives the most sunlight, which allows phytoplankton to perform photosynthesis.

Question 2

What’s the compensation point?

Answer 2

It’s the area in the water body where the photosynthetic rate becomes zero.

Question 3

What’s the aphotic zone?

Answer 3

Portion of the water body that has little to no sunlight.

Question 4

What’s the benthic zone?

Answer 4

The lowest level of a water body such as lakes, oceans, and stream (includes sediment surface and sub surface layers; littoral).

Question 5

What’s the pelagnic zone?

Answer 5

Refers to open and free waters in the oceanic body. It stretches between the ocean surface and bottom; marine life can swim freely without constraints.

Question 6

What’s the profundal zone?

Answer 6

The deepest portion of the ocean.

Question 7

What does “PAR” stand for?

Answer 7

Photosynthetically Active Radiation

Question 8

Why does PAR matter?

Answer 8

These refer to wavelengths of light that is absorbed by pigments in chloroplasts/thylakoids to help create sugars.

Question 9

What are pigments?

Answer 9

Molecules that absorb light energy; different molecules can absorb different wavelengths.