Senin, 24 Desember 2012

The Double Helix


Review by       : Tika P. Agustina
http://psychedelicadventure.blogspot.com
NIM                : 201110070311026
Class                : Biologi I A
Our body have more than billion cells. And  in the cell there is nucleus, sorrounded by  solute that like jelly called cytoplasm, and cytoplasm bounded by a thin cell membrane. In the inside nucleous there is DNA. DNA built by deoxyribose, a phosphate group, and one of four bases called adenine (A), guanine (G), cytosine(S), thymin (T). The bases A,G,S,and T make  strands like rungs on a ladder. Notice that the bases always from spesifc pairs, example bases A always pair with U and T.
DNA or deoxyribonucleic acid is controled our cell. DNA always has same structure it’s from two long strand that wind around each other to from a double helix, or spiral, similar to a telephone cord. DNA  made by coded instruction called genes, that needed to build and controled cells activity. importantly, it’s can also copy itself when cells divide.
In the human body have 46 chromosomes. chromosome consists of DNA and we have known that DNA consists of nucleotides. Each nucleotide consists of deoxyribose sugar-celled, another component called a phosphate group, and one of the four bases DNA can replicate or make copies of itself. This occurs just before a cell is mitosis or meiosis. The result is two cells have identical genes. each base will pair up with her partner, and form a series of letters like the AUG, to form two new DNA strands are identical


By :Stere jones, profesor of genetics and author of darwin’s ghost ,
Page 28-29

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