How are checkpoints currently behaving in sally cancer cells ?

Two checkpoints are sensitive to DNA damage, one that acts before mitosis and a second that acts before DNA replication. This is relevant to cancer because checkpoint mutants show genetic instability, and such instability is characteristic of many cancers.

b

explanation:

only about ten percent of the energy at one trophic level is passed on to organisms at the next trophic level. the remainder of the energy is used in life processes or lost as heat.