Which macromolecule is the primary energy source for organisms?
question 2 options:
a) sunlight
b) protein
c) fat
d) carbohydrate
e) nucleic acid

the backbone of the dna and rna compound is sugar phosphate.

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.