A ___(J) is a group of individuals of the same species that mate and produce offspring. In each generation, new genotypes occur that express themselves as specific individual (K)___. Any factor that affects the (L)___ of a population can change the frequency of ___(M)___, resulting in evolution over time. Through the processes of variation and ___(N)___, new species can arise. A ___(P)___ is a population of physically similar, interbreeding organisms that do not interbred with other such groups.

(J) population; (K) phenotypes; (L) gene pool; (M) alleles; (N) natural selection; (P) species

Explanation:

A population is a group of organisms living in a particular geographical area that is capable of interbreeding, while a species is a group of populations that are capable of interbreeding and producing fertile progeny. In a population, genetic variation can enter from one of these sources: 1-recombination (i.e., the exchange of DNA between homologous chromosomes during meiosis), 2-mutations (i.e., genetic alterations resulting from DNA replication), 3-migration of individuals between populations, or 4-lateral or horizontal gene transfer (i.e., the acquisition of genetic material between individuals without direct vertical inheritance, it is extremely rare in higher organisms). Alleles are gene variants which are may be created, for example, through mutation, while the gene pool refers to the total genetic diversity (i.e., alleles) that exists within a population. Finally, natural selection refers to the evolutionary process of differential reproduction and survival through which populations adapt and change.

Chief cells in the parathyroid gland synthesize and release parathyroid hormone.

Explanation:

Parathyroid gland contains two types of cells- Chief cells and Oxyphil cells.

The chief cells in the parathyroid gland synthesize and release parathyroid hormone.

The function of the parathyroid hormone is to regulate the level of calcium in the blood. They do this by increasing the calcium levels when they are too low.