Answer:
The best answer is R group. An R - group is a chemical group or side chain that is found attached to the central carbon in amino acids
Explanation:
This figure illustrates 3 hypotheses of how a cancer stem cell may arise: (1) A stem cell undergoes a mutation, (2) A progenitor cell undergoes two or more mutations, or (3) A fully differentiated cell undergoes several mutations that drive it back to a stem-like state.
A.) Launch a satellite
Landing on the moon takes years to figure out. (How, when, what is the purpose, etc.) Capturing an asteroid is beyond difficult and would also take years to figure out how to do so.
Launching a space probe has yet to be done BUT we have had a satellite launched (hence how we get satellite images.)
