AP BIOLOGY

Detailed explanation-1: -Most aquatic and semi-aquatic animals swim by moving their bodies or tails side to side, or up and down. This wave-like motion is called undulation and it is used by reptiles, whales, and fish.

Detailed explanation-2: -Reptiles such as crocodiles and alligators, for example, move themselves through water by undulating their tails from side to side. Their undulating spines coordinate the movements of the four legs propelling them on land.

Detailed explanation-3: -Undulation is a flowing, up-and-down movement like the motion of waves. Have you ever looked out over the ocean and watched the water flow up and down in waves? If so, you watched undulation, which is exactly that type of movement. Undulation best applies to waves, but it can also describe similar movements.

Detailed explanation-4: -ˌən-də-: a rising and falling in waves. : a wavelike motion to and fro in a fluid or elastic medium propagated continuously among its particles but with little or no permanent translation of the particles in the direction of the propagation : vibration.

Detailed explanation-5: -We shall see that this distinction is not entirely accurate, and also less useful than one based on the wavelength of actuation, in that, broadly speaking, undulatory swimmers display a wavelength shorter than their body length, and oscillatory swimmers display a wavelength longer than their body length.