Neither whales nor pythons have hind legs, but both have internal remnants of legs and hip bones. snakes and whales must have i. evolved from ancestors that walked. ii. developed morphological adaptations for transportation. iii. had their legs bitten off by their mothers at birth.

I. evolved from ancestors that walked

Explanation:

Whales and pythons have vestigial structures, which are structures (hind legs) which are no longer useful to them since they have evolved. The ancestors of the whale and python did use the hind legs but over generations the whale and snake have adapted to new environments and they no longer need them.

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.