The wings of butterflies and birds are structures because, although they are used for the same purpose (flight) they have very different structural compositions. Bird wings are made of bones and feathers while butterfly wings are made from chitin and are part of the insect’s exoskeleton. A) homologous
B) analogous
C) vestigial

Describe the iron sulfide hypothesis and the lipid membrane hypothesis.

An ecologist studied the same species of deer during the summer and the winter. she noticed that during the summer, when there was plenty of food, the deer were energetic and playful. however, during winter when food was scarce, the deer moved more slowly and did not run unless they needed to escape a predator. which scientific fact is best supported by her observations?

In "the pig," what is the main effect that the piglet initially has on kibuka?