Ostriches have wings, but do not fly.  Humans have an appendix with no apparent function.  Whales contain bones for rear legs.  Each of these are examples ofGroup of answer choicesnatural selectionvestigial structuresanalogous structureshomologous structures

In humans, the pelvis and thigh bone are used for walking. Whales also have a tiny pelvis and thigh bone, which suggests they used to have legs. The pelvis and thigh bone in a whale are examples of ________.Group of answer choiceshomologous structuresfossilsnatural variationvestigial structures

Whales have pelvic (hip) bones, even though they don't have legs. These are called vestigial structures - bones or other structures that aren't useful but are still there. What do whales' pelvic bones suggest?AThat whales are mammals and have much of the DNA as human beingsBThat one whale was born without legs and now no whales have legsCThat whales have an ancestor that had legsDThat whales are related to sharks

The flipper of a dolphin and the leg of a horse are known as  Group of answer choicesNumerical structureAnalogous structuresHomologous structuresAnatomical structures

The structures of the front flipper of a whale and the forearm of a wolf have similar bone structure and derive from a common ancestor. This is an example of which of the following?

Flipper of a whale and wing of a bat have the similarI. basic functionII. external morphologyIII. pattern of bone arrangementA. I only.B. III only.C. I and II.D. II and II