AP BIOLOGY

Detailed explanation-1: -In humans, each cell normally contains 23 pairs of chromosomes, for a total of 46. Twenty-two of these pairs, called autosomes, look the same in both males and females. The 23rd pair, the sex chromosomes, differ between males and females.

Detailed explanation-2: -Humans typically have 23 pairs of chromosomes, or 46 chromosomes in total. Chromosomes are made up of long strands of DNA, which contain all the body’s genes.

Detailed explanation-3: -Scientists have numbered the chromosome pairs from 1 to 22, with the 23rd pair labeled as X or Y, depending on the structure. The first 22 pairs of chromosomes are called autosomes. The 23rd pair of chromosomes are known as the sex chromosomes, because they decide if you will be born male or female.

Detailed explanation-4: -Egg and sperm cells have just 23 chromosomes each. That’s half as many chromosomes as regular cells. Through the process of fertilization, egg and sperm join to make a cell with 46 chromosomes (23 pairs), called a zygote. For each chromosome pair, one homologous chromosome came from each parent.

Detailed explanation-5: -"This is because in the human evolutionary lineage, two ancestral ape chromosomes fused at their telomeres [tips], producing human chromosome 2. Thus, humans have one fewer pair of chromosomes. This is one of the main differences between the human genome and the genome of our closest relatives."