Chromosomes

Definition

Chromosomes are thread-like structures located inside the nucleus of animal and plant cells. Each chromosome is made up of protein and a single molecule of deoxyribonucleic acid (DNA). Humans have 23 pairs of chromosomes which carry genes - units of heredity controlling specific traits.

Related terms

Genes: These are segments within DNA located on chromosomes that contain instructions for building proteins – the building blocks for everything in your body.

Alleles: These are different versions or forms of the same gene found at the same place on a chromosome.

Karyotype: This refers to an individual's collection of chromosomes. It's like taking inventory to see what recipe books (chromosomes) you have in your library (nucleus).