What principle suggests that gene pair separates during

After fertilization, which type of cellular division is responsible for the growth and development of a complex, multicellular organism?

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.

Genetic disorders can result when sister chromatids fail to seperate properly. during what phase is this problem most likely to occur?