Q: You are presented with the quiz "What aren't diseases caused by?"   But you don't know the answer, so you turn to your teacher to ask for hints. He says that "populations of viruses do not grow through cell division because they are not cells" and "viruses are the cause of many diseases".   So, what's the best answer to the question?
A: cells

Q: You are presented with the quiz "What uses stems to store water?"   But you don't know the answer, so you turn to your teacher to ask for hints. He says that "astem is used to store water by some plants" and "ferns are vascular plants".   So, what's the best answer to the question?
A: ferns

Q: You are presented with the quiz "What is one thing most single-celled organisms have in common?"   But you don't know the answer, so you turn to your teacher to ask for hints. He says that "most protists have motility" and "protists Protists are single-celled organisms".   So, what's the best answer to the question?
A: motility

Q: You are presented with the quiz "What must an animal find to ensure survival?"   But you don't know the answer, so you turn to your teacher to ask for hints. He says that "an animal needs to attract a mate to reproduce" and "every member of every species needs to meet the challenges of survival and of reproduction".   So, what's the best answer to the question?

A: mate