Given a scientific passage and an answer, generate a question for the given answer.

[EX Q]: Passage: An experiment is a controlled scientific study of specific variables. A variable is a factor that can take on different values. For example, the speed of an object down a ramp might be one variable, and the steepness of the ramp might be another. Answer: variable
[EX A]: In a controlled scientific study, what do you call a factor that can take on different values?

[EX Q]: Passage: Connective tissue consists of cells that form the body's structure. Examples include bone and cartilage, which protect and support the body. Blood is also a connective tissue. It circulates and connects cells throughout the body. Answer: connective
[EX A]: What tissue consists of cells that form the body's structure?

[EX Q]: Passage: Fish have a nervous system with a brain. Fish brains are small compared with the brains of other vertebrates. However, they are large and complex compared with the brains of invertebrates. Fish also have highly developed sense organs. They include organs to see, hear, feel, smell, and taste. Answer: fish
[EX A]:
What category of animals in the vertebrate group has a relatively small brain but highly developed sense organs?