You take a sample of bacteria with DNA that contains only 14N and allow these cells to replicate in a medium that contains only 15N. After 3 rounds of replication, what percent of the DNA molecules will contain one strand with only 14N and one strand with only 15N?

Theories basic to all of the life sciences include the germ theory of disease. theory of evolution by natural selection. o two of these answers are correct none of these answers are correct o cell theory.

Which statement describes a way in which the digestive and excretory systems work together? a. the nephrons absorb nutrients from food going to the large intestine. b. the excretory system balances blood gases in the small intestine. c. the intestinal villi filter blood and send wastes to the bladder. d. the excretory system balances the salts and water obtained from digested food

Which situation is an example of not doing work? lifting a couch throwing a baseball running up stairs carrying a box