For Each of the Following Sentences, Fill in the Blanks

Essay

For each of the following sentences, fill in the blanks with the best word or phrase selected from the list below.Not all words or phrases will be used; each word or phrase should be used only once.
$\begin{array}{lll}\text { anaphase } & \text { differentiation } & \text { myostatin } \\\text { annihilation } & \mathrm{G}_{0} & \text { nourishment } \\\text { arrestase } & \mathrm{G}_{1} & \text { nutrition } \\\text { Bcl2 } & \mathrm{G}_{2} & \text { phosphatases } \\\text { biosynthetic } & \text { growth factors } & \text { proliferation } \\\text { cyclin } & \text { interphase } & \text { receptor } \\\text { cascades } & \text { ligand } & \mathrm{S} \\\text { caspase } & \mathrm{M} & \text { survival factors } \\\text { Cdk } & \text { mitogens } & \text { transcription }\end{array}$

The survival, __________, and size of each cell in an animal are controlled by extracellular signal molecules secreted by neighboring and distant cells.Many of these signal molecules bind to a cell-surface __________ and trigger various intracellular signaling pathways.One class of signal molecules, called __________, stimulates cell division by releasing the molecular brakes that keep cells in the __________or __________ phase of the cell cycle.Members of a second class of signal molecules are called __________, because they stimulate cell growth and an increase in cell mass.The third class of signal molecules, called __________, inhibits apoptosis by regulating members of the __________ family of proteins.In addition to such stimulatory factors, some signal proteins, such as __________ act negatively on other cells, inhibiting their survival, growth, or proliferation.