What are these pairs of chromosomes called?

Question

People often refer to the human genome as being comprised of 23 pairs of chromosomes. What are these pairs called? How do these pairs relate in regard to size, genes, and alleles? Make sure to answer both questions to earn credit.

Answer 1

We have 46 chromosomes, or in other words, 23 pairs. Pairs 1-22 are called autosomes. The 23rd pair is the sex chromosomes.

The autosomes are homologous chromosomes. These chromosomes are approximately the same size and contain the same genes at the same loci (location), meaning that they code for the same traits. Homologous chromosomes differ in that they can carry different alleles (different versions of genes). For example, two homologous chromosomes could both have a gene for blood type in the same location, but one chromosome could have the allele for blood type A, and the other chromosome could have the allele for blood type B.

Answer 2

Every cell in the human body contains 23 pairs of such chromosomes; our diploid number is therefore 46, our 'haploid' number 23. Of the 23 pairs, 22 are known as autosomes. These pairs are referred to as homologous chromosomes. We have 46 in total resulting in 23 pairs. These chromosomes represent one from our father and one from our mother. That is how we get our genetic material. There are various alleles and genetic codes on each chromosome - that is why we are all individually unique.