Essential Genetics Vocabulary

Genotype and phenotype are the foundation of genetics - think of genotype as your genetic recipe (the actual DNA code) and phenotype as the finished dish (what you actually look like or how you function). Your genotype is hidden inside your cells, whilst your phenotype is what everyone can see.

When it comes to alleles (different versions of the same gene), they don't all behave the same way. Dominant alleles are like that loud friend who always gets their way - they'll show up in your appearance even if there's only one copy. Recessive alleles are more polite and only show up when there are two copies present.

Homozygous means you've got two identical alleles for a trait (like AA or aa), whilst heterozygous means you've got two different ones (like Aa). Codominant alleles are special because both get to show off equally - think of blood type AB where both A and B appear together.

Quick Tip: Remember that mitosis makes identical cells (like photocopying), whilst meiosis makes genetically different gametes with half the chromosomes (essential for sexual reproduction). The sex chromosomes XX make you female, and XY make you male.