How does a vascular plants xylem differ from its phloem? a. the material that flows in the xylem is only water. b. only xylem transports carbohydrates. c. the materials in xylem flow in only one direction. d. only xylem is found in roots.

Hershey and chase confirmed that dna, not protein, was the genetic material. how do the results of their two experiments support this conclusion?

Why are carbon dioxide concentrations expected to increase? a carbon dioxide concentrations are expected to increase, because fossil fuel burning is expected to increase b. carbon dioxide concentrations are expected to increase, because of an increase in agriculture. c.carbon dioxide concentrations are expected to increase, because more land will have to be cleared for increasing populations and agricultural use. d. all of the above select the best answer from the choices provided mark this and return save and exit next submit submit

How do disease caused by bacteria and disease caused by viruses react to antibiotics