Many freshwater one celled organisms, like paramecium, have contractile vacuoles. there's structures collect and pump out excess water that accumulates in the cell. explain why these organisms needs such a structure.

What are the four basic classes of organic molecules how do they differ structurally and functionally

What are ways that ordinary people can to keep antibiotic resistance from getting worse?

The hershey and chase experiments involved the preparation of two different types of radioactively labeled phage. which of the following best explains why two preparations were required? a. the bacteriophage used in the experiments was a t2 phage. b. it was necessary that each of the two phage components, dna and protein, be identifiable upon recovery at the end of the experiment. c. each scientist had his own method for labeling phage, so each conducted the same experiment using a different isotope. d. establishing the identity of the genetic material required observation of two phage generations.