Sex different species of a small bird called a chickadee live in North America. Each species lives in a different region of the continent, but all the species have similar physical features.

Explain the evolutionary relationship between these bird species.

Ineed the answer asap. in order to be considered alive, an organism must simultaneously possess the characteristics of homeostasis, heredity, cells, reproduction, and

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.

How does human environment effect the biosphere