In gel electrophoresis, an electrical current is used to separate different sizes of DNA molecules. What size is found
at the bottom of a gel?
a. the shorter DNA molecules
b. the longer DNA molecules

Specialized cells which perform a particular function form : organisms organs tissues

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.

Which direction does the energy flow in this energy pyramid ?