The rDNA sequences of which organisms branch nearest the root of the archaean tree? Choose one: A. Crenarchaeota B. Euryarchaeota C. Thaumarchaeota D. Ancient Archaeal Group

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.

How was the climate when the ambulocetus was alive

List two modern organisms that have pentameral symmetry