DNA and chromosomes
For most of the time, Deoxyribonucleic acid. The material inside the nucleus of cells, carrying the genetic information of a living being. exists in the nucleus as thin strands. When the cells containing nuclei are ready to divide, the DNA copies itself then coils and condenses to form The structure made of DNA that codes for all the characteristics of an organism..
Each chromosome is made from a single molecule of DNA. Each section of this single molecule of DNA contains a code for the production of a particular Organic compound made up of amino acid molecules. One of the three main food groups, proteins are needed by the body for cell growth and repair. called a 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..
Each human body cell contains 46 chromosomes. These can be arranged into 23 pairs. Each chromosome in a pair carries the same types of genes.
The 23rd pair is the sex chromosomes. In females, the two chromosomes are identical in shape. These are X chromosomes. Females are referred to as XX. In males, one of the chromosomes is different in shape. This is a Y chromosome. Males are referred to as XY.
Learn more about DNA and the genome with Dr Alex Lathbridge.
Listen to the full series on 大象传媒 Sounds.
In this podcast, learn the key facts about DNA: what it is, how it's made and how it works. Listen to the full series on 大象传媒 Sounds.