Which class of biomolecule do the molecules in the table belong to? O A.
carbohydrates
O B.
proteins
O C.
lipids
D.
nucleic acids

What links the two strands in a dna helix together in the middle? a. phosphate groups b. sugar rings bonded together c. proteins d. bases with hydrogen bonds

Where do the respiratory and circulatory systems meet? a. in the heart b. in the muscles c. in the lungs d. in the brain

Isolated volcanic peaks on the ocean floor are