What are difference between a gene and alleles ;give an example of multiple alleles for a gene?
A gene is a specific segment of DNA that contains the instructions for producing a protein or functional RNA molecule. Genes code for traits or characteristics of an organism.
Alleles, on the other hand, are different forms or variants of a gene. They are alternative versions of a gene that can exist at the same locus (specific position) on a chromosome. Alleles arise due to mutations or changes in the DNA sequence of a gene.
An example of multiple alleles for a gene is the ABO blood group system in humans. The gene responsible for blood type determination is called the ABO gene, and it has three main alleles: A, B, and O. Each person inherits two alleles for the ABO gene, one from each parent. The A and B alleles code for specific proteins on the surface of red blood cells, while the O allele codes for no protein. The different combinations of these alleles result in different blood types: A, B, AB, and O.