Question

Which hypothesis regarding what limits food- chain length has the most support?
A.Energy transfer hypothesis
B.Stability hypothesis
C.Environmental complexity hypothesis
D.All of the above

Answer 1

Hint:
A food chain can be understood as the sequence in which energy and nutrients are transferred from one trophic level to another. Only 10% of energy in the form of calories gets transferred among various trophic levels of a food chain. Animals feed on each other and obtain energy in the ecosystem.

Complete step by step answer:
Food chain begins with producers which generally includes those animals who are autotrophic and can produce their own food such as plants. Second level includes herbivores called primary consumers who feed on plants such as grasshoppers or cattle. Next trophic level is of secondary consumers who are carnivores and feed on primary consumers such as bird or man respectively, and so on.

There are many hypotheses and theories about different factors affecting the food chain. The hypothesis that is well discussed in ecology regarding the factor that limits the food chain length is the energy transfer hypothesis.

So, the correct answer is A, Energy Transfer Hypothesis.

According to this hypothesis, the energy gets transferred from one level to another as organisms feed on each other. But only 10% of the energy is transferred so this may lead to a level where there won't be any more energy left to be transferred. Thus, this inefficiency in energy transfer limits the length of the food chain.

Note:
On an average, a food chain is only 4-5 trophic levels long. The length of the food chain indicates the chances of organisms to survive environmental changes. As the energy goes from one level to another, animals obtain a considerable amount of energy to survive but in higher levels, there is no amount of energy left to be obtained by any organism.