THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -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.

Detailed explanation-2: -Chromosomes come in pairs. Normally, each cell in the human body has 23 pairs of chromosomes (46 total chromosomes). Half come from the mother; the other half come from the father. Two of the chromosomes (the X and the Y chromosome) determine your sex as male or female when you are born.

Detailed explanation-3: -If sex cells, like sperm and egg, have the same number of chromosomes as regular body cells, then each time they combined, the progeny would have twice the number of chromosomes. This doesn’t happen. So, there must be a process that halves chromosome number in sex cells.

Detailed explanation-4: -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.