We humans are all part of the same species: Homo sapiens. A species is defined as the largest group of individuals that can produce fertile offspring.
When the parents are the same species, the order of the traits in the decks are the same, meaning in this example, eye color will be the first card in both decks, hair color will be the second card in both decks, and so on and so forth.
During meiosis, the cell division process for sex cells, some of the cards in the mother’s deck switch with the corresponding card in the father’s deck. This helps produce functional, healthy sex cells and enables the child of the mother and father to be able to reproduce.
But when the mother and the father are from two different species, the order of the cards in the mother’s deck is different than the father’s deck. So, during the switching process, the mother’s traits don’t get switched with the father’s corresponding traits.
But, there is a special case where female mules are able to reproduce. They are somehow able to skip the switching process, and their sex cells consist of just the mother’s DNA. These female mules are able to produce offspring that, since their sex cells are the exact same as their mother’s, are strangely also the female mules’ genetic half-sibling.
All humans are 99.9% genetically similar. Even though we’re that genetically similar, we have many differences — a variety of ethnicities, skin colors, personalities, etc. Just like we have these differences, so do other species. DNA is the blueprint for our body. Chromosomes are long strands of DNA and genes are the sections of chromosomes that code for a trait.
Genes have different forms, which are called alleles. We get one allele from our mother and one allele from our father. When the alleles are identical, it’s called homozygous, and when they’re different, it’s called heterozygous. Some alleles are dominant, while others are recessive.
