Question

This force can stabilize a DNA helix:
A. Hydrophilic sugar-phosphate groups are found on the exterior of the helix where interaction with water occurs.
B. Hydrophobic bases are present in the interior of the helix; each base pair is stabilized by the same number of hydrogen bonds
C. Covalent base stacking interactions may take place between neighbouring bases within the same strand in the helix
D. Non-covalent N-glycosidic bonds may form between nitrogenous bases in opposite strands in the helix

Answer 1

Hint:
By base-pairing, Watson and Crick determined the structure of DNA, which consists of two strands of polynucleotide chains. The nitrogenous bases are positioned inside the sugar-phosphate backbone that forms the chain's structure.

Complete answer:
Two right-handed polynucleotide chains make up the double helix structure. The double helix is formed by the polynucleotide chains, which are coiled on the same axis and run next to one another. The complementary nature of the two polynucleotide chains is demonstrated. Therefore, the sequence of bases in other strands can be predicted if the sequence of bases in one strand is known.
Both strands are antiparallel to one another, therefore if one was orientated from 3 to 5 in a direction, the other would be from 5 to 3 in that same direction.
By forming hydrogen bonds between base pairs, both strands are kept together. Thymine from the opposing strand and adenine establish two hydrogen bonds. Similar to this, Guanine and Cytosine establish three hydrogen bonds. Right-handed coiling is used for both chains. The double helix DNA has a pitch of 3.4 nm. There are roughly 10 base pairs per turn. The regular spacing between DNA base pairs is 3.4. Each entire turn of the double helical structure contains about 25 hydrogen bonds that give it stability comparable to a covalent link. DNA is a hydrophilic molecule that is stabilized by the sugar-phosphate moiety.
Hence, the correct option is Hydrophilic sugar-phosphate groups are found on the exterior of the helix where interaction with

Option ‘A’ is correct

Note:
In contrast to DNA, RNA has uracil rather than thymine. Every nucleotide residue in RNA contains an extra hydroxyl group at the 2' position of the ribose. Less complex bodies give lower species a lesser genetic code than more complex, larger organisms.