TREE TRUNKS STRUCTURE Sapood
Heartwood
Dead bank
Ure bark
Cambium-
Pith
Growth rings
Medullary rays
4. In tree rings, like those shown, each "ring" of growth represents what?
O A. One year of growth
O B. One season of growth
O C. One month of growth
O D. Two years of growth
What’s the answer ?

(drag each tile to the correct location.) categorize each term as something that is typical of a scientific theory, a scientific hypothesis, or both. - a tentative statement used to guide scientific investigations. - makes predictions about future events. - can be tested by many independent researchers. - based on observations of natural phenomena. - a well-established, highly reliable explanation.

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.

One of the purposes of transcription is to produce a sequence of bases that