Given a scientific question, generate a correct answer to it.

[EX Q]: What type of organism is commonly used in preparation of foods such as cheese and yogurt?
[EX A]: mesophilic organisms

[EX Q]: Hormones, ions, and neurotransmitters are all types of what?
[EX A]: chemical signals

[EX Q]: What tool is useful for studying the ocean floor because the environment is remote and underwater?
[EX A]:
sonar