Sex determination is the biological system that determines the development of sexual characteristics in an organism. It involves genetic, environmental, and sometimes social factors that lead to the distinction between male and female individuals.
congrats on reading the definition of sex determination. now let's actually learn it.
Sex determination systems vary widely among different species, with some relying on chromosomes (like XY in humans) and others on environmental conditions (like temperature in reptiles).
In mammals, the presence of a Y chromosome typically leads to male development due to the SRY gene triggering male-specific pathways.
Birds use a ZW sex-determination system where males are ZZ and females are ZW.
In many fish and amphibians, sex can be influenced by environmental factors such as temperature or social interactions.
Some animals exhibit sequential hermaphroditism, changing sex during their lifetime based on environmental or social cues.
Review Questions
What is the role of the SRY gene in mammalian sex determination?
How does the ZW sex-determination system work in birds?
What environmental factors can influence sex determination in reptiles?
Related terms
Genetic Sex Determination: A system where sex is determined by specific chromosomes at fertilization.
Environmental Sex Determination: A process where external factors like temperature determine an organism's sex.