Question

The dominant second trophic level, in a lake ecosystem is
A. Benthos
B. Plankton
C. Zooplankton
D. Phytoplankton

Answer 1

Hint: A lake ecosystem formed by combining the biotic (living) plants, animals and microorganisms, as well as abiotic (nonliving) physical and chemical interactions. Lake ecosystems are a part of the lentic ecosystems. Lentic stands for stationary or relatively still water. In the Latin lentus, means sluggish.

Complete Answer:
- The term limnology is defined as the study of inland water. In land water includes lakes, reservoirs, rivers, streams, wetlands, and groundwater.
- Inland water is of two types: Lotic (running water) and Lentic (standing water).
- Lake is lantic and it is a body of water which is occupied in a basin and lacking continuity with sea. Trophic level is a part of the food chain which is understood by the method of obtaining food.
There are two types of trophic levels: Producers and consumers.
- Producers come under first trophic level and In a lake the producers rooted or floating plants, suspended macrophytes, and phytoplanktons.
- Primary consumers come under the second trophic level which feed on living plants or parts of plants. The primary consumers are zooplankton (ciliates, flagellates, rotifers, small crustaceans, like Cyclops, Daphnia).

Correct answer: So, the correct answer is Zooplankton.

Note: Aquatic plants live in both the benthic and pelagic zones, and can be classified according to their manner of growth:
(I) Emergent = rooted in the substrate, but with leaves and flowers into the air.
(II) Floating-leaved = rooted in the substrate, but with leaves are floating.
(III) Submersed = growing under the surface.
(IV) Free-floating macrophytes = not rooted in the substrate, and floating on the surface.