Heredity. Chromosomes. We discussed earlier in this unit, the usage of karyotype charts Humans have 23 pairs of chromosomes 1 sex chromosome pair 22 autosome pairs Recall that males have one X and one Y, while females have two X’s
A square represents
A circle represents
A vertical line and a bracket connect the parents to their children.
A horizontal line connecting a male and a female represents a marriage.
A shaded circle or square indicates that a person expresses the trait.
A circle or square that is not shaded indicates that a person does not express the trait.
These only work for traits that are thought to be controlled by genetics alone
Finally, some conditions are caused by dominant alleles, although it is uncommon