Mercury and the moon are both heavily cratered. what do these two bodies have in common that give them this common characteristic?

Darius is observing a family of geese, which includes a male goose, female goose, and several goslings. when a dog approaches the geese, the male goose hisses at the dog and flaps its wings threateningly. is the behavior of the male goose an example of an adaptation?

Agene in a type of bacteria when the ses bacteria reproduce asexually this mutation can only be inherited by

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.