Contrasting and comparing an allele and a gene

A gene is a section of DNA which codes for certain characteristics such as height in humans. Genes, however can have variations. So, alleles are genes but with variations. For example, a short allele or a tall allele in a person will determine their height. Therefore, Alleles are different variations of genes. They are different sequences of bases in DNA that result in determining a single characteristic. They occur in pairs and can be classified as recessive or dominant.