The nucleus of a cell contains chromosomes, which carry genetic information in a long molecule called DNA. Genes are regions of DNA that carry the code to control a particular cell activity or the production of a particular protein.
Asexual reproduction produces genetically identical individuals, but sexual reproduction produces unique individuals.
The nucleus of a cell contains chromosomeschromosomes: Rod shaped bodies found in the nucleus of cells that contain genetic information (DNA). that carry genetic information. Most body cells have the same number of chromosomes, but this varies between species. Human body cells, for example, each have 23 matching pairs of chromosomes.
Chromosomes are made from long, coiled molecules of DNA [DNA: The material inside the nucleus of cells, carrying genetic information. DNA stands for Deoxyribonucleic Acid. ]. A gene gene: The basic unit of genetic material inherited from our parents. A gene is a section of DNA which controls part of a cell's chemistry - particularly protein production. is a shorter region of DNA that carries the genetic code for a particular characteristic or cell activity.
DNA molecules contain chemicals called bases. Note that these are not the bases you come across in chemistry - which neutralise acids. DNA contains four different bases. Each gene has a different sequence of bases, coding for different products.
The four bases in DNA are labelled A, T, C and G.
Only some of the genes are used in any individual cell, with the rest being switched off. Genes code for the production for proteins. Some of these are enzymes which control how the cell functions.
This slideshow demonstrates how a protein is produced using the genetic code.
How a protein is produced using the genetic code
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.