What is a main difference in cell structure between an onion cell and a human cheek cell?

In trying to determine whether dna or protein is the genetic material, hershey and chase made use of which of the following facts? a) dna contains sulfur, whereas protein does not. b) dna contains phosphorus, whereas protein does not. c) dna contains nitrogen, whereas protein does not. d) dna contains purines, whereas protein includes pyrimidines.

Modern sea star larvae resemble some primitive vertebrate larvae. this similarity may suggest that primitive vertebrates

Some scientists argue that global warming is related to buming fossil fuels to produce energy o increased use of fertilizers loss of forested areas a of the above