What permits some cancer cells in a tumor to resist treatment while other cancer cells die from the treatment

What is the correct answer for the process of water eroding soil? rills, sheet erosion, gullies sheet erosion, rill, gullies gullies, rills, sheet erosion sheet erosion, gullies, rills

Ihave a question. diplontic animals usually produce both eggs or sperm which are :

If a cell loses control of gene expression what happens?