Genetic Diagrams

Punnett squares are genetic diagrams that are used to show the results of a genetic cross.

Genetic disorders caused by recessive alleles have a 25% chance of being transmitted if both parents are carriers, whereas genetic disorders caused by dominant alleles have a 50% chance of being transmitted if one parent is a sufferer and the other parent is normal.

The sex chromosomes are the 23rd pair in humans with women having a pair of X chromosomes and men having both X and Y.