The importance of chromosomes, genes, and DNA
What are chromosomes?
Chromosomes are structures found within the cell nucleus. Each chromosome consists of a molecule of deoxyribonucleic acid (DNA) paired with a molecule of ribonucleic acid (RNA) in a tightly organized, compact structure. DNA contains genes; humans have 23 pairs of chromosomes.
What are genes?
Genes are the units that store information and allow for hereditary transmission from parents to offspring. Genes are segments of DNA. The complete set of genes of a species is called its genome. The genome represents all the genetic information possessed by an organism. Humans have approximately 20,000 genes.
What is deoxyribonucleic acid (DNA)?
DNA is the abbreviation for deoxyribonucleic acid. DNA is a molecule made up of two long chains that run in opposite directions, twisting around each other to form a double helix. In chromosomes, DNA is organized in such a way that it fits inside the nucleus. This form of DNA organization is called packaging.
DNA contains the genes necessary for the development and functioning of all living things. DNA can store, long-term, the information with the instructions for producing cellular components such as proteins and ribonucleic acid (RNA) molecules.
RNA is a molecule similar to DNA but differs in that it is single-stranded. RNA has several functions, including assisting DNA in protein synthesis.