Why do you look like your parents, but not exactly? Breed pea plants and puppies like the scientist Gregor Mendel, and predict what the babies will look like!
HOW GENES WORK
Living things have genes: instructions for things like flower color or fur color. You get two copies of each gene: one from each parent.
Some versions are dominant (a big letter, like P for purple flowers). Others are recessive (a small letter, like p for white).
If a plant has even one big P, the flowers are purple: PP and Pp both look purple. Only pp is white.
Each parent passes on just one of its two letters, by chance. A Punnett square shows every way the letters can join up.
In the 1860s, the monk Gregor Mendel discovered these rules by growing thousands of pea plants!