Why do baby animals look like their parents — but not exactly? Today you'll learn the rules of heredity, then you will predict what the babies look like before they hatch.
Before we start — you look a little like your family, but not exactly the same — why do you think that is?
A gene controls a trait, like a coat's spots. Each parent passes down one copy (an allele) — so every baby gets two, one from each parent.
A dominant allele (big S) shows up if a baby has even one. A recessive allele (little s) only shows when a baby has two of them. So SS and Ss are spotted; only ss is plain.
Put one parent's two alleles across the top and the other's down the side. Each box mixes one from each — showing every kind of baby they could have, and how likely each is.