7.What is the main function of the heart? to exchange gases
to remove waste materials from the body
to produce red blood cells
to move blood through the body

Are needed by the body in large amounts in order to maintain good health

Water pollution cannot only affect the earth's water supply but it can also affect the soil true or false

Aresearcher lyses a cell that contains nucleic acid molecules and capsomeres of tobacco mosaic virus (tmv). the cell contents are left in a covered test tube overnight. the next day this mixture is sprayed on tobacco plants. we expect that the plants would ) develop some but not all of the symptoms of the tmv infectionb) develop the typical symptoms of tmv infectionc) not show any disease symptomsd) become infected, but the sap from these plants would be unable to infect other plants