How many liters of blood circulate through the human body

True or false mucous membranes destroy pathogens on the outer body surface, at body openings.

Asoccer mom is driving her 75 year old grandmother and her 9 year old daughter home after the game. the grandmother and daughter were both in the back seat and both were wearing their seat belts. a car ran a red light in front of them, causing them to t-bone that car on the passenger side. fortunately there were no serious injuries, but the grandmother did sustain several rib fractures. the mother, daughter and driver of the at-fault car were shaken up but unhurt. what are some possible reasons that the grandmother sustained rib fractures while the other victims did not?

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