Gene

• What is a gene

1. A gene is the basic physical and functional unit of heredity. Genes, which are made up of DNA, act as instructions to make molecules called proteins.
   


2. sequence of DNA that codes for a protein and thus determines a trait.



3. A hereditary unit consisting of a sequence of DNA that occupies a specific location on a chromosome and determines a particular characteristic in an organism. Genes undergo mutation when their DNA sequence changes.

• How is it controlled?
  

1. A variety of genes are involved in the control of cell growth and division. The cell cycle is the cell’s way of replicating itself in an organized, step-by-step fashion. Tight regulation of this process ensures that a dividing cell’s DNA is copied properly, any errors in the DNA are repaired, and each daughter cell receives a full set of chromosomes. The cycle has checkpoints (also called restriction points), which allow certain genes to check for mistakes and halt the cycle for repairs if something goes wrong

• How do it work?

• What is so special about the DNA of red blood Cell?

1. Red blood cells in mammals do not have a cell nucleus, and therefore do not have DNA; they also do not have other organelles like mitochondria, and produce energy through glycolysis of glucose – a fermentation process – followed by lactic acid production. Their glucose uptake is not regulated by insulin. They are shaped like disks with indentations on top and bottom, optimizing them for exchanging oxygen by maximizing surface area. They are also flexible, allowing them to fit into the tinest capillaries. Adult humans have 2-3 x 1013 red blood cells at any given time, with men and people living in high altitudes having more. Blood types are differentiated by different surface glycoproteins.

• And how is its' specialty adapted to it's function?
  

*a gene can be turn on in off this is called gene regulation.

*Gene regulation can occur at any point during gene expression, but most commonly occurs at the level of transcription (when the information in a gene’s DNA is transferred to mRNA).

*If a cell has an error in DNA it can not be repaired.