LIFE SCIENCE

Detailed explanation-1: -Healthy humans have 46 chromosomes, 23 from the sperm and 23 from the egg.

Detailed explanation-2: -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-3: -The 23rd pair of chromosomes are two special chromosomes, X and Y, that determine our sex. Females have a pair of X chromosomes (46, XX), whereas males have one X and one Y chromosomes (46, XY). Chromosomes are made of DNA, and genes are special units of chromosomal DNA.

Detailed explanation-4: -A sperm and an egg each contain one set of 23 chromosomes. When the sperm fertilises the egg, two copies of each chromosome are present (and therefore two copies of each gene), and so an embryo forms. The chromosomes that determine the sex of the baby (X and Y chromosomes) are called sex chromosomes.