The hypothesis by Coleman was that the product of the ob+ gene was the appetite suppressing hormone. Hence, the homozygous ob/ob mutant are in a position to synthesize that hormone, and its circulating level would be zero. He also hypothesized that the product of the db+ gene was the receptor for the appetite-suppressing hormone. Thus, the homozygous db/db mutant would be able to synthesize the hormone but would not be in a position to respond to it. It would eat excessively and produce large amounts of body fat, which in turn would produce large amounts of appetite-suppressing hormone . In the absence of a receptor, the db/db mutant's hormone level would remain abnormally high.
Coleman's hypothesis were confirmed when the precise functions of the ob+ and db+ genes were determined. The peptide hormone encoded by the ob+ gene was named Leptin.
They work to convert light energy of the sun into sugars that can be used by cells
The correct answer is: Individuals that produce chemical compounds are better protected from herbivores and are able to produce more young than individuals that do not produce the compounds.
Natural selection acts on variations-differences in phenotype that exist among individuals. If a certain trait contribute more to survival and reproduction (individuals with that variant survive more than individuals with other variant), natural selection will favor that trait. In this case, production of chemical compounds is favored over non-producing trait.
