DNA nucleotides are attached bya)Hydrogen bondb)Covalent bondc)Van der Waals bondd)Electrovalent bondCorrect answer is option 'A'. Can you explain this answer?

Question

Answer

Explanation: DNA nucleotides are attached by the Hydrogen bond. A nucleotide is the basic unit of polynucleotide chain of DNA (deoxyribonucleic acid) or RNA (Ribonucleic acid).

The nitrogenous bases are found in the strand's inward direction. The nitrogenous bases of the two antiparallel strands form hydrogen bonds, resulting in the formation of two helical strands.

The nitrogenous bases used in DNA (double-stranded helical structure) are adenine (A), cytosine (C), guanine (G), and thymine (T).

Adenine is joined to thymine with two hydrogen bonds, whereas guanine is joined to cytosine by three hydrogen bonds.

Thus, DNA nucleotides are attached by Hydrogen bond.

Answer

Nucleotides are joined together by covalent bonds between the phosphate group of one nucleotide and the third carbon atom of the pentose sugar in the next nucleotide. This produces an alternating backbone of sugar - phosphate - sugar - phosphate all along the polynucleotide chain

Answer

Hydrogen bond
DNA nucleotides are attached by hydrogen bonds. These bonds play a crucial role in maintaining the structure and integrity of the DNA molecule.

Structure of DNA
DNA (deoxyribonucleic acid) is a double-stranded molecule that carries the genetic information in all living organisms. It consists of two complementary strands that are held together by a series of chemical bonds, including hydrogen bonds.

Nucleotides
DNA is composed of repeating units called nucleotides. Each nucleotide consists of three components: a sugar molecule (deoxyribose), a phosphate group, and a nitrogenous base. There are four different nitrogenous bases in DNA: adenine (A), thymine (T), guanine (G), and cytosine (C).

Base pairing
The two DNA strands are held together by base pairing interactions between the nitrogenous bases. Adenine forms hydrogen bonds with thymine (A-T), and guanine forms hydrogen bonds with cytosine (G-C). This complementary base pairing ensures that the genetic information is accurately transmitted during DNA replication and protein synthesis.

Hydrogen bonds
Hydrogen bonds are relatively weak chemical bonds that form between a hydrogen atom and an electronegative atom, such as oxygen or nitrogen. In the case of DNA, hydrogen bonds form between the nitrogenous bases of the two strands.

Hydrogen bonding in DNA
The hydrogen bonds in DNA play a crucial role in stabilizing the double helix structure. Each base pair is connected by two or three hydrogen bonds, which provide sufficient stability for the DNA molecule.

Weak and reversible
Hydrogen bonds are weak and reversible, which allows the DNA strands to separate during processes such as DNA replication and transcription. These processes involve the breaking of hydrogen bonds between the base pairs, allowing the DNA to be copied or transcribed into RNA.

Summary
In summary, DNA nucleotides are attached by hydrogen bonds. These bonds play a critical role in maintaining the structure and integrity of the DNA molecule. Hydrogen bonds form between the complementary nitrogenous bases, allowing the DNA strands to be held together in a double helix structure. The weak and reversible nature of hydrogen bonds is essential for DNA replication and transcription.

Answer

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