AP BIOLOGY

Detailed explanation-1: -A diploid cell has two complete sets of chromosomes. Most cells in humans are diploid, comprising 23 chromosome pairs, so 46 chromosomes in total. This is 22 pairs of autosomes and a pair of sex chromosomes. One copy of each chromosome pair came from the individual’s mother and the other from the individual’s father.

Detailed explanation-2: -Humans have 46 chromosomes in each diploid cell. Among those, there are two sex-determining chromosomes, and 22 pairs of autosomal, or non-sex, chromosomes. The total number of chromosomes in diploid cells is described as 2n, which is twice the number of chromosomes in a haploid cell (n).

Detailed explanation-3: -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.

Detailed explanation-4: -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. They have the same genes arranged in the same order, but there are small variations in the DNA letters of those genes.

Detailed explanation-5: -The correct determination of the human diploid chromosome number as 46, by J-H Tjio and A Levan, at the University of Lund, Sweden, occurred 50 years ago, in December 1955; the finding was published in April 1956, ending a period of more than 30 years when the number had been thought to be 48.