Concepts of Biology

Kindle Highlights

Genes, the functional units of chromosomes, determine specific characteristics by coding for specific proteins.

In eukaryotes, the genome comprises several double-stranded, linear DNA molecules (Figure 6.2) bound with proteins to form complexes called chromosomes.

The matched pairs of chromosomes in a diploid organism are called homologous chromosomes. Homologous chromosomes are the same length and have specific nucleotide segments called genes in exactly the same location, or locus.

Human body cells (somatic cells) have 46 chromosomes. A somatic cell contains two matched sets of chromosomes, a configuration known as diploid. The letter n is used to represent a single set of chromosomes; therefore a diploid organism is designated 2n. Human cells that contain one set of 23 chromosomes are called gametes, or sex cells; these eggs and sperm are designated n, or haploid.