What must occur for a message to be sent from the outside of the cell to
inside the cell?
a. a signaling molecule binds with a membrane protein.
b. transport proteins form a channel for a large molecule.
c. enzymes inside the cell catalyze a reaction.
d. a small, nonpolar molecule crosses the membrane.

Which units ate used to measure both velocity and speed? check all that apply

Sarah and john are having a discussion on genetic diversity. sarah believes that it happen over a long period of time. john it happens immediately. who is correct? a. sarah is correct because genetic diversity occurs over a long period of time. b. john is correct because genetic diversity occurs immediately. c. both are correct because genetic variation can occur or long period of time. d. neither are correct because genetic diversity occurs over any period of time

Match the functions to the cell types ? contraction and relaxation. conducting electrochemical signals fighting diseases carrying genetic material