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A double-stranded nucleic acid that contains the genetic information for cell growth, division, and function.


Structure: DNA is composed of two strands that twist together to form a helix. Each strand consists of alternating phosphate (PO4) and pentose sugar (2-deoxyribose), and attached on the sugar is a nitrogenous base, which can be adenine, thymine, guanine, or cytosine. In DNA, these bases pair; adenine pairs with thymine and guanine with cytosine. Hence, DNA is a ladder-like helical structure.

Location: DNA is found in the cytoplasm of prokaryotic cells, and chiefly in the nucleus of eukaryotic cells. A small fraction of total DNA is present in mitochondria and chloroplasts.

Function: DNA is a long polymer of nucleotides to code for the sequence of amino acid during protein synthesis. DNA is said to carry the genetic ‘blueprint’ since it contains the instructions or information (called genes) needed to construct cellular components like proteins and RNA molecules.

Word origin: abbreviation of deoxyribonucleic acid.
See also: gene, base pair, genetic code, RNA.

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Help: Confused with primers in a PCR of a vector?

... I should get are: 1) T3 - coding region - T7 2) ??? It looks like it WON'T be a proper PCR reaction? Will we just get one massive chunk of DNA? 3) coding region - T7 4) T3 - coding region I think the point of this entire process was to just determine the directionality of our insert. Because ...

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by keetner
Sat Mar 15, 2014 3:21 am
Forum: Molecular Biology
Topic: Help: Confused with primers in a PCR of a vector?
Replies: 0
Views: 167

Gel electrophoresis

toooo much DNA

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by JackBean
Wed Mar 12, 2014 2:24 pm
Forum: Genetics
Topic: Gel electrophoresis
Replies: 3
Views: 379

Re: Why do Africans have large noses and lips?

I don't know the answer to this specific question, but we do know some things about how genes are linked on DNA. Sometimes a trait that is helpful for survival is very closely associated with another trait on the DNA strand. So when natural selection keeps trait A in the gene ...

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by anneland
Sun Mar 09, 2014 6:54 pm
Forum: Human Biology
Topic: Why do Africans have large noses and lips?
Replies: 30
Views: 188405

Polymorphism and Mutation

... to a single individual that may or may not be propagated. For example a single point mutation where a base is replaced or deleted from a strand of DNA. This may cause the individual some discomfort or problems but is normally isolated to the individual. A polymorphism is a distinct population of ...

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by Babybel56
Wed Mar 05, 2014 3:39 am
Forum: Molecular Biology
Topic: Polymorphism and Mutation
Replies: 2
Views: 318


Here is a task: Look at the picture - you see three DNA sequences from three species that are related. Based on that sequence only, draw a cladogram that best represents their relatedness. http://i59.tinypic.com/2jbmgax.jpg My thoughts: Since species ...

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by leeroykincaid
Tue Feb 25, 2014 8:09 pm
Forum: Evolution
Topic: cladograms
Replies: 7
Views: 406
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