What are the side rails of DNA called?

The double helix looks like a twisted ladder—the rungs of the ladder are composed of pairs of nitrogenous bases (base pairs), and the sides of the ladder are made up of alternating sugar molecules and phosphate groups.

There are two sides to the double helix, called the sugar-phosphate backbone, as they are made from alternating phosphate groups and deoxyribose sugars. The “steps” of the double helix are made from the base pairs formed between the nitrogenous bases.

- BRAINLIEST answerer

phosphate and deoxyribose molecules

Explanation:

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.

the water is warmed up by the sun and then it evaporates into the atmosphere. the sunlight warms the water by its heat. water is then cooled down and condensation takes place. the water then finally returns back to the earth by the process of precipitation in the form of rain or ice.

explanation: