Final answer:
Chromosomes are composed of deoxyribonucleic acid (DNA) and proteins, which include histones. They contain genes that dictate genetic instructions, with human cells possessing 46 chromosomes. DNA within chromosomes is essential for cellular function and heredity.
Step-by-step explanation:
Chromosomes are composed of deoxyribonucleic acid (DNA) and proteins, specifically histones. DNA contains the genetic instructions necessary for building and maintaining an organism, and these instructions are arranged into genes. A single chromosome may contain hundreds to thousands of genes, and humans have 46 chromosomes (23 pairs). Each chromosome is a strand of DNA wrapped around histones and coiled into its characteristic structure during cell division.
DNA controls cellular activities by turning genes "on" or "off" and is involved in protein synthesis, using different types of RNA, such as messenger RNA (mRNA), for communication and regulation within the cell. Overall, chromosomes serve as the repositories for genetic information and play a crucial role in the transmission of genetic information to daughter cells during cell division.