In what situation is it hard to determine the phenotype of a person?

6. in the dna double helix, how are the two strands of dna held together? a. chemical bonds between base pairs hold the two strands of dna together. b. hydrogen bonds between the base pairs hold the two strands of dna together. c. hydrogen bonds between sugar groups and phosphate groups hold the two strands of dna together. d. chemical bonds between sugar groups and phosphate groups hold the two strands of dna together.

What is the importantence of the carbon and nitretan cycles in the environment

Apart of an ecosystem that can restrict the growth of a population is referred to as