A scientist is studying how chemical messages are transferred between cells of a developing embryo. In a research journal, the scientist draws a diagram to illustrate how the embryonic cells at the bottom of the early embryo are releasing chemicals to nearby cells to elicit protein production in the activated neighboring cells.

DIAGRAM IS ATTACHED

What is the primary purpose of the signaling molecule?

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 the diagram explain ocean currents? earth tilt 23.5 degreesquestion 1 options: earth's tilt causes uneven heating of earth which causes currents. earth's tilt causes the ocean to move because of gravity. earth's tilt and its rotation cause currents. earth's tilt causes uneven distribution of salt which causes currents.

Describe how viruses and bacteria can be used as biological weapons. what are some of the potential threats and potential benefits? do you agree with the use of viruses and bacteria as biological weapons? why or why not?