Living Environment Regents Practice Test – Exam Prep & Study Guide

An allele is defined as a variant form of a gene. Genes, which are segments of DNA, can come in different forms that may produce variations in the traits they encode. For example, the gene for flower color in plants may have a variant for red flowers and another for white flowers. These variant forms are what we refer to as alleles. Each individual inherits two alleles for each gene, one from each parent, and these can be either identical or different.

This understanding is key in genetics, particularly in explaining how traits are passed from generation to generation and the basis for genetic variation within populations. The other options misrepresent the concept: identical copies describe homozygous alleles, typing chromosomes pertains to the structure of DNA, and cell nucleus structures do not define alleles.