Question

Describe DNA and working of it...

Answer 1

DNA is made up of molecules called nucleotides. Each nucleotide contains a phosphate group, a sugar group and a nitrogen base. The four types of nitrogen bases are adenine (A), thymine (T), guanine (G) and cytosine (C). The order of these bases is what determines DNA's instructions, or genetic code

Answer 2

DNA) is a molecule composed of two chains (made ofnucleotides) that coil around each other to form a double helix carrying thegenetic instructions used in the growth, development, functioning andreproduction of all known livingorganisms and many viruses. DNA andribonucleic acid (RNA) are nucleic acids; alongside proteins, lipids and complex carbohydrates (polysaccharides), nucleic acids are one of the four major types ofmacromolecules that are essential for all known forms of life.

The two DNA strands are also known aspolynucleotides since they are composed of simpler monomeric units called nucleotides.[2][3] Each nucleotide is composed of one of four nitrogen-containing nucleobases (cytosine [C],guanine [G], adenine [A] or thymine [T]), a sugar called deoxyribose, and aphosphate group. The nucleotides are joined to one another in a chain bycovalent bonds between the sugar of one nucleotide and the phosphate of the next, resulting in an alternating sugar-phosphate backbone. The nitrogenous bases of the two separate polynucleotide strands are bound together, according to base pairing rules (A with T and C with G), with hydrogen bonds to make double-stranded DNA.

The complementary nitrogenous bases are divided into two groups, pyrimidinesand purines. In DNA, the pyrimidines are thymine and cytosine; the purines are adenine and guanine.