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प्रश्न
How is the structure of DNA organized?
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उत्तर
DNA is the hereditary material, as it contains genetic information. It is a large molecule consisting of millions of nucleotides, so it is called a polynucleotide. Each nucleotide consists of three components.
(a) A sugar molecule – Deoxyribose sugar
(b) A nitrogenous base – There are two types of nitrogenous base in DNA they are
- Purines (Adenine and Guanine)
- Pyrimidines (Cytosine and Thymine)
(c) A phosphate group – The polynucleotide chains from a double helix. Nitrogenous bases in the centre are linked to sugar-phosphate units, which form the backbone of the DNA. Pairing between the nitrogenous bases is very specific and is always between purine and pyrimidine, linked by hydrogen bonds.
Adenine (A) links Thymine (T) with two hydrogen bonds [A=T]. Cytosine (C) links Guanine (G) with three hydrogen bonds (C = G). The hydrogen bonds between the nitrogenous bases make the DNA molecule stable. The nucleotides in a helix are joined together by phosphodiester bonds.
Structure of DNA
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संबंधित प्रश्न
Name the enzyme and state its property that is responsible for continuous and discontinuous replication of the two strands of a DNA molecule
Correct the following statement if there is any mistake.
The four nitrogenous bases in the DNA are Guanine, Thiamine, Adrenaline and Cytosine.
A structure not present in all chromosomes is ______.
The DNA double-helix model was given by ______.
New nucleotides are added and a new complementary strand of DNA is formed with the help of enzyme DNA polymerase.
A DNA strand with the sequence AACGTAACG is transcribed. What is the sequence of the mRNA molecule synthesized?
In what year did Watson, Crick, and Wilkins receive the Nobel Prize in Physiology or Medicine for DNA research?
How many hydrogen bonds form between adenine and thymine in complementary base pairing?
What is the pitch (vertical rise per complete turn) of the DNA double helix?
