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Deoxyribonucleic acid (view source)
Revision as of 04:43, September 23, 2007
, 04:43, September 23, 2007→Modern understanding
Small parts of DNA called [[gene]]s serve as the instructions for the body to carry out its functions and give rise to traits such as eye color, hair color, etc. <ref>"Eye-color genes, through the proteins they encode, direct the amount and placement of melanin in the iris." [http://www.hhmi.org/cgi-bin/askascientist/highlight.pl?kw=&file=answers%2Fgenetics%2Fans_044.html Ask A Scientist - Genes and eye color]</ref> Genes are packaged into [[chromosomes]]. Each individual human being has 23 pairs of chromosomes, where one set is inherited from his/her mother and the other set is inherited from his/her father.
Small parts of DNA called [[gene]]s serve as the instructions for the body to carry out its functions and give rise to traits such as eye color, hair color, etc. <ref>"Eye-color genes, through the proteins they encode, direct the amount and placement of melanin in the iris." [http://www.hhmi.org/cgi-bin/askascientist/highlight.pl?kw=&file=answers%2Fgenetics%2Fans_044.html Ask A Scientist - Genes and eye color]</ref> Genes are packaged into [[chromosomes]]. Each individual human being has 23 pairs of chromosomes, where one set is inherited from his/her mother and the other set is inherited from his/her father.
[[Prokaryotic DNA]] is circular (a closed loop), while [[Eukaryotic DNA]] is linear (with ends) with the exception of [[Mitochondrial DNA]], which is circular too. DNA in [[prokaryote]]s usually consists only of one closed loop chromosome.<ref>Campbell, Neil A, et. al. ''Biology''. 6th ed. San Francisco: Benjamin Cummings, 2002. 299, 530-31.</ref>
[[Porkaryotic DNA]] is circular (a closed loop), while [[Eukaryotic DNA]] is linear (with ends) with the exception of [[Mitochondrial DNA]], which is circular too. DNA in [[porkaryote]]s usually consists only of one closed loop chromosome.<ref>Campbell, Neil A, et. al. ''Biology''. 6th ed. San Francisco: Benjamin Cummings, 2002. 299, 530-31.</ref>
DNA changes account for differences between individuals. However, they can also cause medical problems.
DNA changes account for differences between individuals. However, they can also cause medical problems.