Allele vs. Gene

How are alleles and genes different? And how do they correspond with each other?

Alleles are pairs of genes and help code for an organism. Genes come from the parent organisms in order to help with the make up of an organism. 

There are always two genes in an allele, if the genes are the same then the allele they make are considered to be homozygous, if the genes are different then the allele is heterozygous. An example of a homozygous allele would be if both parent organisms have blue eyes. They would then pass the blue eyed genes down to their offspring and their offspring would have blue eyes.

A heterozygous allele is a bit more complicated then homozygous allele. A heterozygous allele receives two genes just like the other but depending on what gene is domiment is the trait that the organism gets, although there are some exceptions where there can be a mix of the traits. A normal example of a heterozygous allele would be where one of the parent organisms has blue eyes and the other has brown. Brown eyes is a dominate trait so most likely the organism will have brown eyes. In some rare occasions an organism could have brown eyes but with a small amount of blue in them.