Question

Explain how organisms in lakes are related through the flow of energy. Read More >>

Answer 1

Ecosystems maintain themselves by cycling energy and nutrients obtained from external sources. At the first trophic level, primary producers (plants, algae, and some bacteria) use solar energy to produce organic plant material through photosynthesis. Herbivores—animals that feed solely on plants—make up the second trophic level. Predators that eat herbivores comprise the third trophic level; if larger predators are present, they represent still higher trophic levels. Organisms that feed at several trophic levels (for example, grizzly bears that eat berries and salmon) are classified at the highest of the trophic levels at which they feed. Decomposers, which include bacteria, fungi, molds, worms, and insects, break down wastes and dead organisms and return nutrients to the soil
I got this passage from Annenberg Learner

Answer 2

Answer:  

Lake is a type of natural ecosystem as it possesses both biotic ( living components such as plants, algae, micro-organism, and animals) and abiotic (nonliving components such as water, light, temperature, oxygen content, pH of water) factors.

The different living organisms are related through the flow of energy ( in the form of organic matter) in the food chain ( a linear network between organisms, representing energy transfer in the form of organic matter) that takes place within this ecosystem.  

For example-  

Phytoplanktons ( microscopic plants) and algae-  they are autotrophic organisms that form the base of the food chain as they synthesize their own food through photosynthesis. They occupy the first trophic level and called producers.

Producers are eaten by primary consumers such as zooplankton, small fishes, ducks ( which all are herbivores).

Primary consumers are eaten by secondary consumers such as large fishes.

In this manner flow of energy occurs between different organisms in the lake.