The given diagram is food chain. Food chain is a sequence of populations or organisms of an ecosystem through which the food and its contained energy passes with each member becoming the food of a later membre of the sequence. The number of trophic levels in a food chain is 3-6 and in each trophic level a lot of biomass is consumed in liberating energy.
In the above food chain plants( producers) radiant light energy into chemical form. Rodents are primary consumer, owl is a secondary consumers or primary carnivores and wolf is a tertiary consumer or secondary carnivores.
Used by people is the answer. :-)
Ans.
Steroids are defined as active organic bio-molecules, having four rings with a specific molecular configuration. Steroids play role in two major functions: as hormones or signaling molecules and as structural components of plasma membrane.
Examples of steroid hormones are estrogen, progesterone, and cortisol. Thus, the correct answer is 'option b). they serve as chemical messengers.'