Why can’t cells continue to grow past a certain size?

Last week i was assigned a thematic. we have groups of three but the people i was assigned with haven't been in school for days. i would appreciate if anyone can me with my thematic . i highlighted most of the important steps and i circled my thematic topic. in desperate need : ( its due on february 19

Isolated volcanic peaks on the ocean floor are

Which of the following was not a major animal on land during the carboniferous period? amphibians insects both a and b none of the above