Which layer of the uterus is the site for implantation of an embryo?

this process is called "phosphorylation." a phosphate bond joins adenosine diphosphate to form adenosine triphosphate.

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.