The Enigma of DNA

in General 01 January 1999

Deoxyribonucleic acid, known by the majority of us as DNA, is the only thing that makes you, you. It’s a pretty hard one for anyone who’s not a scientific professional to understand but it is only the paired sequence of your DNA that is stopping you from being exactly the same as the person you’re sat next to.

What is DNA?

DNA is inside every cell of every living thing on the planet – it is known as the building block of life. In the human body, each cell nucleus contains 46 chromosomes which make up the 23 DNA pairings. Within every chromosome there are a number of different genes which determine individual features such as hair and eye colour. Within the genes there are base pairs - Adenine, Guanine, Thymine and Cytosine – that are referred to as A, G, T and C for ease. The base pairs are either A and T or C and G and it is these bases that create the ladder-like effect of the DNA double helix. Each end of the ladder-like rungs then attached to a strand of sugar on one side and phosphate on the other, creating the double helix structure that we all associate with DNA.

The genetic difference between men and women

The truth is that although men and women generally look a lot different, genetically their differences are only around 2% and it’s all down to one chromosome. The chromosome that determines the sex of an embryo (X and Y) is the only one that’s different in men and women. In every cell there are 23 pairs of chromosomes; each chromosome is identical to its pair – the only difference being that one comes from the mother and one from the father. Each part of the chromatic duo is pretty much identical – in size and the genes that it contains – in 22 of the pairs, the sex determining chromosomes are different though.

Just like all other chromatic pairings one chromosome comes from the mother (X) and the other from the father (X or Y). X chromosomes however are much bigger than Y as they contain between 2,000 and 3,000 genes whereas the Y chromosome only contains a few dozen useful genes – the rest are useless as they don’t contain instructions for the creation of other molecules.

The only genetic difference between men and women therefore is that whereas women have two X chromosomes, men have one X and one Y.

What is genetic modification and is it possible in humans?

Genetic modification means the same as genetic engineering and involves changing the genes of organisms – plants and animals – in order to improve their chance of survival. Genetic modification allows scientists to modify genes in order to give organisms a better chance of survival by, for example, increasing their resistance to certain diseases or increasing their tolerance to drought.

Traditional breeding would involve crossing two individual plants, animals or other organisms that have a variety of desirable traits with the hope that these desirables will be passed onto the offspring. In reality though the offspring will inherit a number of different traits from its parents – both good and bad – so it will take a number of breeding cycles before offspring with only the desirable traits are produced, which could take a few years.
Genetic modification on the other hand is a much quicker process as it can manipulate the genes of an organism using techniques that aren’t possible in the traditional breeding process. Genetic modification involves taking the desirable genes from one organism and inserting them into another or merely manipulating an organism’s genes in order to create the desired characteristic.

Problems with genetic modification in humans

Despite genetic engineering in plants and animals being a successful techniques that has now been used for years, when it comes to humans there are a huge number of boundaries that still need to be crossed, the biggest of them being ethics.

The truth is that if used as intended genetic modification in humans could actually prevent debilitating diseases and significantly improve people’s way of life which is obviously a huge benefit. However, with the idea of parents being able to choose the eye colour and hair colour of their children along with other forms of human enhancement, it’s a technique that is still deemed completely immoral.

Primer designs are a business that operates within the DNA industry, providing a valuable insight into genetic information routinely to society. Primer Designs PCR primers are used by universities to aid further research into DNA.

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