Question

Consider the horizontal divisions of life in lakes. Which statement is accurate?

1. The division is based on temperature gradients.
2. It is determined by the types of life forms present.
3. All zones have identical conditions for plant growth.
4. The zones are primarily defined by water movement.

• A. 4 only
• B. None of these
• C. 3 only
• D. 2 only

Answer 1

Answer:

D. 2 only

• Littoral zone - This is the shallow water zone, near the shore, where light penetrates to the bottom. Rooted plants can grow only in this region.

• Open Water Zone - This zone extends beyond the littoral zone and is too deep for light to penetrate till the bottom and for rooted plants to grow.

• Benthic Zone - This zone forms the floor of the lake and underlies the littoral and limnetic zone.