A hormone is a molecule that functions as a chemical signal. A hormone is a chemical released by a cell or a gland in one part of the body that sends out messages that affect cells in other parts of the organism. Endocrine hormone molecules are secreted (released) directly into the bloodstream. !
The set of all alleles at all loci is the full gene pool<span> for the species. Over time, the size of a </span>gene pool<span> changes. The </span>gene pool<span> increases when a </span>mutation<span> changes a </span>gene<span>and the </span>mutation<span> survives </span>
Genetic variation is an important force in evolution as it allows natural selection to increase or decrease frequency of alleles already in the population. ... Genetic variation is advantageous to a population because it enables some individuals to adapt to the environment while maintaining the survival of the population.
