NEET BIOLOGY

Detailed explanation-1: -Double helix, as related to genomics, is a term used to describe the physical structure of DNA. A DNA molecule is made up of two linked strands that wind around each other to resemble a twisted ladder in a helix-like shape. Each strand has a backbone made of alternating sugar (deoxyribose) and phosphate groups.

Detailed explanation-2: -To avoid bumping into each other, the staircase has to twist a little bit. This turns our staircase into a spiral staircase. This extra twist at the end is the reason for the helical shape. For the “steps” of the DNA “staircase” to fit together, they have to twist a little bit, making the final spiral shape of DNA.

Detailed explanation-3: -Concept 19 The DNA molecule is shaped like a twisted ladder. Other key experiments showed that the ratios of A-to-T and G-to-C are constant in all living things. X-ray crystallography provided the final clue that the DNA molecule is a double helix, shaped like a twisted ladder.

Detailed explanation-4: -Nucleotides are arranged in two long strands that form a spiral called a double helix. The structure of the double helix is somewhat like a ladder, with the base pairs forming the ladder’s rungs and the sugar and phosphate molecules forming the vertical sidepieces of the ladder.