LIFE SCIENCE

Detailed explanation-1: -Definition. A phosphate backbone is the portion of the DNA double helix that provides structural support to the molecule. 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.

Detailed explanation-2: -The DNA strand’s “backbone” is constituted by pentose sugar and phosphate, while the nitrogenous bases project inside forming the bridges between the strands.

Detailed explanation-3: -Sugar-phosphate backbone is linked to phosphodiester bond between carbon 4 and CH2 group that attached to phosphate ion thus make the DNA strand as double helix making it twist into a coil.

Detailed explanation-4: -They confirmed that DNA is a double helix in which two strands of DNA wind around each other like a twisted ladder. The sugar and phosphate molecules form the outside strands of the helix, and the bases pair together in the middle, forming hydrogen bonds that hold the two sides of the helix together.