Question

From where the food chain starts and it ends?
A. Starts with carnivores and ends with omnivores
B. Starts with primary producers and ends with carnivores
C. Starts with omnivores and ends with primary producers
D. Starts with herbivores and ends with carnivores

Answer 1

Hint: Food chain and food webs are integral parts of the ecosystem and the natural environment. A typical food chain helps in the proper transfer of energy to all the biotic components of an ecosystem. In a healthy ecosystem, a healthy and functional food chain is an important feature. In most ecosystems two types of food chains can be traced namely the detritus food chain and the grazing food chain.

Complete answer:
Option: A - A food chain can never start from carnivores since they cannot play the role of producers by preparing their own food from light energy.
Thus, this option is not correct.
Option B - This option is correct because a food chain begins from primary producers, the photosynthetic organisms and then ends at carnivores which derive their nutrition by hunting herbivores.
Thus, option B is correct.
Option: C - A food chain cannot begin with the consumers like omnivores and end at primary producers since it can never happen that energy flows from top to the bottom.
Thus, option C is not correct.
Option: D - Herbivores are consumers and food chains never begin from consumers.
Thus, option D is also not correct.

Therefore, Option (B) is the correct answer.

Note:
Food chains represent the direction of flow of tropic energy from producers to consumers. In reality, an ecosystem contains many intertwined food chains which together constitute food webs. In a typical food chain, the first trophic level is occupied by primary producers of photosynthetic organisms and the other trophic levels are occupied by the consumers of herbivores, omnivores and carnivores.