20.
what makes up the backbone of a dna molecule?
ribose and deoxyribose
nucleic acids
rna molecules
sugars and phosphates

Which sentences describe the logistic growth model? there are three different phases of the s-shaped curve. at first, growth is exponential because individuals are few and resources are plenty. this growth model occurs in a situation where resources are plenty and individuals are few to consume the resources. population growth decreases as resources become limited. when a population size reaches the carrying capacity of its environment, the population growth slows down or stops completely. the model looks like a j-curve.