Chromosomes and Genes
Chromosomes are essential structures made of DNA that contain the master instructions for your cells. Each chromosome has two arms separated by a centromere, with the short arm called "petit" and the long arm called "queue."
Your chromosomes contain sections called genes, which carry specific codes for every trait in your organism. The different forms of these genes are called alleles. When chromosomes exist in matching pairs (called homologous chromosomes), they contain genes for the same traits arranged in the same order.
During reproduction, chromosomes make copies of themselves called sister chromatids. Homologous chromosomes separate during meiosis, allowing for genetic variation in offspring. If your alleles are homozygous (identical), your offspring inherit the same trait. If they're heterozygous (non-identical), offspring can inherit either trait.
Did you know? Scientists can create a karyotype—a picture of all your matched chromosomes arranged by size—to identify chromosome numbers and types. This helps detect genetic abnormalities caused by changes in chromosome structure or number.
