The secretion of a signal molecule by a cell into the local environment, followed by a response by a number of cells in the immediate vicinity, is an example of . *

What is the next step in muscle contraction after the actin changes shape? (apex)

1. describe the structure and function of the specialized cells you observed in the video. 2. research the types of cells present in the kidney.

What do isotopes of uranium have the same number of? what do they have a different number of? a) same number of protons; different number of electrons b) same number of protons; different number of neutrons c) same number of electrons; different number of protons d) same number of neutrons; different number of protons