Question

The given figure represents the different zonation in deep lake. Which of the following is incorrect regarding it?

• A. $Y$ represents light and oxygen levels.
• B. Only consumers are found in $E.$
• C. Producers do not occur in $A.$
• D. $D$ receives light at or below compensation point.

Answer 1

Answer: (C)

A deep lake show significant and proper zone-differentiation. The uppermost area, surface of the water can receive direct sunlight and is rich in photoautotrophs or the producers. The following are the zones of a lake:

• The littoral zone is the area extended from the shore and show rooted plants.
• The photic zone is divided into euphotic and dysphotic zones. The euphotic zone is the lighted and usually well-mixed portion that extends from the lake surface down to where the light level is 1% of that at the surface.
• The aphotic zone is positioned below the littoral and photic zones to bottom of the lake where light levels are too low for photosynthesis. However, respiration occurs at all depths so the aphotic zone is a region of oxygen consumption. This deep, unlit region is also known as the profundal zone.
• The sublittoral zone is the deepest area of plant growth. This is a transition between the littoral and profundal zones.
• Finally, the pelagic zone or limnetic zone is the surface water layer in offshore areas beyond the influence of the shoreline.