Chromosomes = Threadlike structures
in eukaryotic nuclei that are composed of DNA and protein.
· Each species has a characteristic
chromosome number. (Human somatic cells have 46.)
· Gametes (sperm and ova) contain half
the number of chromosomes of somatic cells. (Human gametes have 23.)
Chromatin, a DNA-protein complex, is organized into a long, thin
fiber that is folded and coiled to form the
chromosome. Each chromosome thus contains:1. A long DNA molecule, with thousands of genes.
2. Various proteins that maintain chromosomal structure and help control
gene activity.