Due to decreased light penetration, which area of rivers and streams will have less diversity of plant life? a. the source b. the mouth c. the middle portion d. none of the above

The answer is; B

The mouth because, at this stage of the river, the waters are deep and move slowly. Due to the depth, light cannot penetrate to the river bed hence photosynthetic organisms cannot spur here. Photosynthetic life will only exist on the top waters. Due to the stillness of these waters, they have low dissolved oxygen hence less diversity of plants can exist in these waters, This is why these waters are good for mangroves that have aerial roots.

the answer is a. now keep my answer here.

doctors i believe if i'm wrong sorry