Humans have 46 chromosomes in all diploid somatic cells – 22 pairs are autosomes and the 23rd pair are the sex chromosomes
The Y chromosome includes a gene called the SRY gene (Sex Determining Region Y), which leads to male development
- Females possess two copies of the X chromosome (XX), while males possess one X and a shorter Y chromosome (XY)
The Y chromosome includes a gene called the SRY gene (Sex Determining Region Y), which leads to male development
- The SRY gene codes for a testis-determining factor (TDF) that causes embryonic gonads to form into testes (male gonads)
- In the absence of the TDF protein (i.e. no Y chromosome), the embryonic gonads will develop into ovaries (female gonads)
- The male and female gametes produce different hormones to promote further development of sex characteristics:
- The testes produce testosterone to promote the further development of male sex characteristics
- The ovaries will produce estrogen and progesterone to promote the development of female sex characteristics