Which term is the sense used by bats and dolphins to locate objects by emitting sound and listening for echoes?

• A. Gas Exchange
• B. Exoskeleton
• C. Echolocation
• D. Gastropoda

Answer: (C)

Echolocation is the sense used by bats and dolphins to locate objects by emitting sound and listening for echoes. When these animals send out calls—bats with ultrasound and dolphins with clicks—the sound travels through air or water, bounces off objects, and returns as echoes. By measuring how long the echo takes to return, they gauge distance; by analyzing the echo’s frequency, amplitude, and changes in timing, they infer the object's size, shape, texture, and even movement. This biosonar lets them navigate and hunt in darkness or murky water where vision is limited. The other terms refer to unrelated ideas: gas exchange is about respiration, an exoskeleton is a external skeleton, and gastropoda is a group of mollusks, none of which describe a sensing method.