What are the differences between alleles and genes?

Answer 1

An allele is a form of a gene. Basically, in simple Mendelian genetics, there are two genes that can be expressed: the dominant form and the recessive form. A pea plant can be tall (dominant) or short (recessive). If a plant is tall, what controls that tallness is a gene. The fact that it is tall is due to the presence of the allele. ----------------------------------------- Simple improvement: The gene locus is the position on the chromosome that controls a specific trait (e.g. colorblindness). Alleles are different genetic sequences that can occur at that position to give a specific trait (colorblind, not colorblind). Since in humans there are two gene loci for each trait (one from mother and one from father), alleles can either be dominant-recessive (recessive only expressed when dominant is absent), codominant, or incompletely dominant, etc.