Howard temin and satoshi mizutani discovered that the rous sarcoma retrovirus contains the enzyme reverse transcriptase. why would it be important for the virus to carry its own reverse transcriptase protein? why wouldn't the virus just make it from its reverse transcriptase gene after it infects the cell?

What did the first language sound like

Which geologic feature would most likely be represented by contour lines john far apart from one another? a cliff a hill a plain a valley

Which is an advantage of having memory cells when a pathogen is encountered for a second time. a) the memory cells are what proliferate into clones of cells in response to the binding of an antigen. b) memory cells are vital to the primary immune response in that they immediately recognize pathogens even at the first encounter. c) memory cells are essentially effector cells that are short lived and attack antigens even without having a receptor specific to that antigen. d) it ensures that more lymphocytes with a receptor specific to a particular antigen will be present than in a host that had never encountered that pathogen.