Which statement correctly describes a level of organization in the human circulatory system? Answers:

Cells are only present in tissues.

O Organ systems are only present in cells.

Tissues are made up of many organs.

Organs are made up of many tissues.

there is no stairs in bungalow

explanation:

poof

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.