Vitamin d-3 is synthesized in the skin in response to sun exposure. question 5 options: a. true b. false

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.

What is the correct answer for the process of water eroding soil? rills, sheet erosion, gullies sheet erosion, rill, gullies gullies, rills, sheet erosion sheet erosion, gullies, rills

Glycogen is an energy-storage molecule in humans. a hormone that is called insulin controls the storage of glycogen in the liver. insulin is made up of amino acids.