In different animals the sex of the progeny is determined in diferent ways ;
After fertilization, in some animals, the
temperature at which the eggs are kept determines the sex
of the progeny.
For Example - Turtles, Alligators, Crocodiles
Thus in such animals, sex is determined by environmental conditions
, on the other hand, can
change their sex
This means that in snails, gender is not genetically determined
In case of
Human beings give birth to male and female children due to genetic reasons.
- Human beings have 23 pairs of chromosomes.
- This makes a total of 46 chromosomes.
- Out of the 23 pairs, 22 pairs (44 chromosomes) have a copy from the mother and father each .
the sex chromosome
, is not always paired perfectly.
- Women have a perfect pair - both are X - XX (Egg)
- Men have one normal sized X chromosome and another short chromosome called Y chromosome - XY (Sperm)
- This means that there is a 50% chance that the child is a male or female.
- Though the sex is determined by which gene is inherited from the father , the process in completely by chance and the probability of the child being male or female is equal.