Sex determination in humans
Sex is determined in humans by the Genetic structures that usually occur in functional pairs in the nucleus of cells (except gametes and bacteria). 23.
In females, there are two X chromosomes.
So, female = XX.
In males, one X and one Y chromosome.
So, male = XY.
An image of a complete set of chromosomes is known as a karyotype.
Reduction division in a cell in which the chromosome number is halved from diploid to haploid. forms A cell that contains half the normal number of chromosomes. gametes (sperm and egg cells).
All eggs contain one X chromosome.
50% of sperm contain one X chromosome and 50% contain one Y chromosome.
During When a sperm nucleus and an egg nucleus fuse together., there is a 50% chance that a sperm containing an X chromosome will fuse with the egg; this would result in a baby girl – XX.
There is also a 50% chance that a sperm containing a Y chromosome will fuse with the egg; this would result in a baby boy – XY.
Within a population there will be equal numbers of females and males.