DNA plays a primary role in all living beings even plants. It’s important because through this you can know your inheritance and coding of protein and guide for life and also for processing of life. DNA holds the instructions for an organism’s or each cell’s development and reproduction and ultimately death. DNA or deoxyribonucleic acid is a long molecule that contains our unique genetic code.
DNA has a unique ‘double helix’ shape, like a twisted ladder. The sides of the ladder are made of alternating sugar and phosphate molecules. The sugar is deoxyribose. The rungs of the ladder are pairs of 4 types of nitrogen bases. This double helix structure was first discovered by Francis Crick and James Watson with the help of Rosalind Franklin and Maurice Wilkins. DNA contains four basic blocks (ACGT) Adenine, Cytosine, Guanine, thymine. Each strand is composed of long sequences of the four bases, A, C, G and T. the bases always bound together with hydrogen bonds. The sequence of these bases is from the instruction in genome. The human genome is made of 3.2 billion bases of DNA but other organisms have different genome sizes. Nearly every cell of a person contains same DNA. Most DNA stored in the cell nucleus called nucleus DNA and a small amount of DNA can be found in mitochondria is called mitochondria DNA.
Parental, forensic and genetic testing look for similarities in the genetic markers between two biological samples. Because all cells in the body contain exactly the same DNA, samples can be taken from almost anywhere in the body, including skin, hair follicles, blood and other bodily fluids. Red blood cells do not have any DNA, as they lose their nuclei (the compartment in a cell that contains the DNA) as they mature. So, the DNA in your blood is in your white blood cells. To get at it, scientists first spin a small sample of your blood at high speed, to separate the cells from the blood fluid.
DNA structure provides an extremely stable backbone with the negatively charged phosphates pointing to the outside of the molecule. This charge aids in the attachment of other molecules to the strand of DNA. DNA double helix allows it to be stable and it won’t easily destroyed. 99.9% of the DNA from two people will be identical. The 0.1% of DNA code sequences that vary from person to person are what make us unique.
The accuracy of DNA tests has big implications. DNA tests are sometimes the only evidence to prove that a suspect was involved in a crime, or free someone who has been wrongly convicted.
Above all, it depends on whether the DNA is exposed to heat, water, sunlight, and oxygen. If a body is left out in the sun and rain, its DNA will be useful for testing for only a few weeks. If it’s buried a few feet below the ground, the DNA will last about 1,000 to 10,000 years.
However, DNA test is very useful to know your ancestors and helps you a lot to make a family tree.