Select Page

Archives: Dictionary


/əˈlēl/ Noun, pl. alleles 1. One of a number of alternative forms of the same gene or same genetic locus (generally a group of genes). It is the alternative form of a gene for a character producing different effects. Sometimes, different alleles can result in different observable phenotypic traits, such as different pigmentation. However, many variations at the genetic level result in little or no observable variation. ( 2. One of two or more alternative forms of a gene that arise by mutation and are found at the same place on a chromosome ( 3. (Genetics) One member of a pair (or any of the series) of genes occupying a specific spot on a chromosome (called locus) that controls the same trait.   Word origin: From German Allel, shortened from Allelomorph, from English allelomorph. Syn:...

Read More


Noun, pl. allelomorphs 1. (Genetics) One of a number of alternative forms of the same gene occupying a given position on a chromosome. (   Syn:...

Read More


/ˈaliˌgātər/ Noun 1. A crocodilian in the genus Alligator of the family Alligatoridae. There are two living alligator species: the American alligator (Alligator mississippiensis) and the Chinese alligator (Alligator sinensis). ( 2. Either of two broad-snouted crocodilians of the genus Alligator, of the southeastern U.S. and eastern China. ( 3. (Botany) Alligator apple, a very large and voracious turtle (Macrochelys lacertina) inhabiting the rivers of the southern united states. It sometimes reaches the weight of two hundred pounds. Unlike the common snapping turtle, to which the name is sometimes erroneously applied, it has a scaly head and many small scales beneath the tail. This name is sometimes given to other turtles, as to species of trionyx. ( Syn: crocodile Word origin: From Latin alligator (“one who ties or binds”), from alligo (“I bind”) + -tor (“agent...

Read More

Allopatric speciation

/ˌaləˈpatrikˌspēSHēˈāSHən/ Noun 1. Speciation that occurs when biological populations of the same species become vicariant — isolated from each other to an extent that prevents or interferes with genetic interchange. This can be the result of population dispersal leading to emigration, or by geographical changes such as mountain formation, island formation, or large scale human activities (for example agricultural and civil engineering developments). ( 2. A speciation in which biological populations are physically isolated by an extrinsic barrier and evolve intrinsic (genetic) reproductive isolation, such that if the barrier breaks down, individuals of the population can no longer interbreed. (   Syn: Geographic speciation Word origin: From the ancient Greek allos, “other” + Greek patra,...

Read More

Struggling in Biology?

Are You Premed?

Confused about the MCAT? Not sure how to prepare? This guide will show you how