Ho do organs compare to organ system

Why reason best illustrates why hershey and chase chose to use viruses in their experiment?

What evidence supports the law of conservation of energy? a) mechanical energy is converted to chemical energy during photosynthesis. b) oxygen is made from the breakdown of carbon dioxide during photosynthesis. c)energy is absorbed by chlorophyll and becomes chemical energy during photosynthesis. d)the sun gives off light energy that is absorbed by plants.

The transport tubes for food coming down the plants are called?