NEET BIOLOGY

Detailed explanation-1: -DNA consists of two strands that wind around each other like a twisted ladder. Each strand has a backbone made of alternating sugar (deoxyribose) and phosphate groups. Attached to each sugar is one of four bases–adenine (A), cytosine (C), guanine (G), or thymine (T).

Detailed explanation-2: -Explanation: DNA stands for “deoxyribonucleic acid.” The backbone of DNA is comprised of alternating sugar and phosphate units, in which the sugar is deoxyribose. The backbone of RNA is also comprised of sugar and phosphate units, but uses the sugar ribose.

Detailed explanation-3: -The sugar in DNA is deoxyribose. The pyrimidines are cytosine (C) and thymine (T); the purines are guanine (G) and adenine (A).

Detailed explanation-4: -The backbone of the DNA is composed of deoxyribose sugar and a phosphate molecule. The four types of nitrogen bases present in a nucleotide are adenine (A), thymine (T), guanine (G), and cytosine (C). The order of these bases determines the DNA’s instructions or genetic code.

Detailed explanation-5: -A sugar-phosphate backbone (alternating grey-dark grey) joins together nucleotides in a DNA sequence. The sugar-phosphate backbone forms the structural framework of nucleic acids, including DNA and RNA. This backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.