Biodiversity

Wednesday, May 03, 2006

THE STRUCTURE AND SIGNIFICANCE OF DNA TO LIFE.

Deoxy Ribonucleic acid (DNA) is a nucleic acid usually in double helix strand( two coiled strands of molecules) containing the genetic instructions specifying the biological development of all cellular forms of life, and most viruses.1 All forms of life have got DNA be it single celled animals(prokaryotes) or multicellular organisms(eukaryotes). For eukaryotes like plants, animal and fungi have most of their DNA found in the nucleus of the cell as compared to the prokaryotes like bacteria that have their DNA in the cytoplasm as they don’t have a distinct nucleus membrane.1

To be able to understand why it is the basis of life we first look at what it is and how it functions to form the basis of life. DNA has two strands shaped like a twisted ladder or a zip and is composed of building blocks called nucleotides consisting of deoxyribose sugar, a phosphate group and any of the four nitrogen bases (nucleobases) Thymine (T), Adenosine (A), Guanine (G) and Cytosine (C). The bases are arranged in an order, such that each base pairs up with another predetermined base to form any of the these A+T, T+A, C+G and G+C forming hydrogen bonds.1 DNA divides into two strands during a process called replication which is more like unzipping giving rise to two strands and with the help of an enzyme the correct bases are matched up to ensue the same form as the original DNA. Only that this time we have two and not one like in the beginning now we’ve got an extra DNA, This process is called replication. In case an error occur during the process of replication it’s known as mutation leading to the wrong information being encoded and will continue being passed on like that.

The DNA contains this hereditary information and also can be changed (transcribed) into RNA which is then partly converted into proteins. This gives us one of the functions of DNA that they are core in the synthesis of proteins. Proteins are essential as they help in body repair and are the building blocks in muscle and are responsible for growth. Therefore it serves as the source of any protein to be formed

DNA is also involved in the passing of hereditary material in life. The hereditary material is stored in genes (which are hereditary units). The genes are encoded in DNA and RNA (ribonucleic acid) and therefore contain the heredity information encoded in them. Therefore for succession to take place DNA is involved and it’s the one transferred from one individual to the other. The traits (characteristics) that define a particular group are passed on from one individual to their offspring through the genes contained in the DNA. They are inherited from the parent or parents depending on whether it’s there’s sexual or asexual reproduction.

It’s argued that in the beginning before there was any life DNA was first formed after Hydrogen, carbon monoxide, ammonia and methane were sparked by ultra violet rays from the lightning.

For life to be there DNA has to be involved to maintain it in terms of protein synthesis and to pass it on in the form of genes.

Reference:

1. Wikipedia contributors. DNA [Internet]. Wikipedia, The Free Encyclopedia; 2006 May 1, 23:16 UTC [cited 2006 May 3]. Available from: http://en.wikipedia.org/w/index.php?title=DNA&oldid=51121850

2. Wikipedia contributors. Gene [Internet]. Wikipedia, The Free Encyclopedia; 2006 Apr 25, 14:09 UTC [cited 2006 May 3]. Available from: http://en.wikipedia.org/w/index.php?title=Gene&oldid=50087668

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