THE STRUCTURE AND SIGNIFICANCE OF DNA TO LIFE.
"The DNA (Deoxyribonucleic acid) is the double helix structure; it is like a long ladder, twisted into a spiral. DNA is a long polymer of nucleotides and encodes the sequence of the amino acid residues in proteins using the genetic code of nucleotides. Sugar and phosphate molecules form the sides of the ladder. DNA is a famous molecule of heredity. Each of us begins as tiny ball about size of a period at the end of a sentence. All physical characteristics that we have e.g. height, hair colour, eye colour are spelled out in our DNA and it guides our development into adulthood. There are four bases making up DNA rings, these are adenine, thymine, guanine, and cytosine. These bases act as the ‘letters’ of a genetic alphabet. They combine in various sequences to form words, sentences, and paragraphs. These bases sequences are all the instructions needed to guide the functioning of the cell" (2)
The cell is very complicated, using many DNA instructions to control its every function; therefore the DNA code is serving as a genetic language that communicates information to the cell. The amount of information in the DNA of even the single-celled bacterium, E.coli, is infinite. The origin of life is the origin of a code. A code represents a specified complexity since is a very special kind of order. (Leslie Orgel, 1973)
DNA as measuring information: The information content of a structure is the minimum number of instructions needed to specify it. The more complex a structure is, the more instructions needed to specify it. Random structures require very few instructions at all. A highly ordered structure likewise requires few instructions if its order is the result of a constantly repeating structure. The discovery that life in its essence is information cut on DNA has greatly shortened the question of life is origin. The information within the genetic code is likewise entirely independent of the chemical makeup of the DNA molecule. The information transmitted by the sequence of bases has nothing to do with the bases themselves and also there is nothing in the chemicals themselves that originates the communication transmitted to the cell by the DNA molecules.
Significance of DNA to life: Micro-organisms represent a powerful tool for improving human lives. With new applications in the industrial, environmental and biomedical fields, the impact that these organisms will have on society seems to stretch further and further across the humankind horizon (4).
"Living things produce more offspring than the finite resources available to them thus living things faces a serious constant struggle for existence. Evolution involves changes in the gene pool. Population are able to maintain a reservoir of variability so that if future condition require it, the gene pool can change (Hardley-Weinberg law) and under this law, genes that have no present selective value will nonetheless be retained. However, evolution depends on mutations because this is the only way that the new genes are created and after being shuffled in various combinations with rest of the gene pool, these provide the raw material on which natural selection can act. Many species such as human, chimpanzee etc. are made up of local populations whose members tend to breed within the group. Each local population can develop a gene pool distinct from that of other local populations. However, members of one population may breed with immigrants from an adjacent population of the same species therefore this can introduce a new gene or alter existing gene frequencies in the residents" (3).
References:
1) Leslie Orgel, 1973. The Origins of Life, New York: John Wiley & Sons, p. 190
2) Wikipedia contributors: [internet]. Online access: 2006 May 03, 12:34 [cited 2006
May 04]. Available from: http://www.origins.org/articles/thaxton_dnadesign.html.
3) Wikipedia contributors: [internet]. Online access: 2006 May 03, 14:21 [cited 2006
May 05]. Available from:
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/H/Hardy_Weinberg.html
4) Wikipedia contributors: [internet]. Online access: 2006 May 03, 10:13 [cited 2006
May 04]. Available from:
Ramapulana Nkoana
CSIR Pretoria
0001
Cell:0733476551
Tell:012 841 2133
Fax:012 842 3676
email: pnkoana@csir.co.za
weblog URL: http://pnkoana.blogspot.com
The cell is very complicated, using many DNA instructions to control its every function; therefore the DNA code is serving as a genetic language that communicates information to the cell. The amount of information in the DNA of even the single-celled bacterium, E.coli, is infinite. The origin of life is the origin of a code. A code represents a specified complexity since is a very special kind of order. (Leslie Orgel, 1973)
DNA as measuring information: The information content of a structure is the minimum number of instructions needed to specify it. The more complex a structure is, the more instructions needed to specify it. Random structures require very few instructions at all. A highly ordered structure likewise requires few instructions if its order is the result of a constantly repeating structure. The discovery that life in its essence is information cut on DNA has greatly shortened the question of life is origin. The information within the genetic code is likewise entirely independent of the chemical makeup of the DNA molecule. The information transmitted by the sequence of bases has nothing to do with the bases themselves and also there is nothing in the chemicals themselves that originates the communication transmitted to the cell by the DNA molecules.
Significance of DNA to life: Micro-organisms represent a powerful tool for improving human lives. With new applications in the industrial, environmental and biomedical fields, the impact that these organisms will have on society seems to stretch further and further across the humankind horizon (4).
"Living things produce more offspring than the finite resources available to them thus living things faces a serious constant struggle for existence. Evolution involves changes in the gene pool. Population are able to maintain a reservoir of variability so that if future condition require it, the gene pool can change (Hardley-Weinberg law) and under this law, genes that have no present selective value will nonetheless be retained. However, evolution depends on mutations because this is the only way that the new genes are created and after being shuffled in various combinations with rest of the gene pool, these provide the raw material on which natural selection can act. Many species such as human, chimpanzee etc. are made up of local populations whose members tend to breed within the group. Each local population can develop a gene pool distinct from that of other local populations. However, members of one population may breed with immigrants from an adjacent population of the same species therefore this can introduce a new gene or alter existing gene frequencies in the residents" (3).
References:
1) Leslie Orgel, 1973. The Origins of Life, New York: John Wiley & Sons, p. 190
2) Wikipedia contributors: [internet]. Online access: 2006 May 03, 12:34 [cited 2006
May 04]. Available from: http://www.origins.org/articles/thaxton_dnadesign.html.
3) Wikipedia contributors: [internet]. Online access: 2006 May 03, 14:21 [cited 2006
May 05]. Available from:
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/H/Hardy_Weinberg.html
4) Wikipedia contributors: [internet]. Online access: 2006 May 03, 10:13 [cited 2006
May 04]. Available from:
Ramapulana Nkoana
CSIR Pretoria
0001
Cell:0733476551
Tell:012 841 2133
Fax:012 842 3676
email: pnkoana@csir.co.za
weblog URL: http://pnkoana.blogspot.com
posted by Ramapulana at
Friday, May 05, 2006
2 Comments:
You have not used quotes to indicate copying more than four words verbatim from a reference. This is plagiarism.
By
Gwen, at May 16, 2006 11:14 AM
hi Gwen
I'm bussy editing
By
Ramapulana, at May 19, 2006 10:17 AM
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