A cat’s front leg and a bat’s wing are considered to be analogous to each other because they share a similar bone structure, even though their functions are different.

The close interaction between organisms of different species over an extended period of time, in which one individual benefits while the other individual neither benefits nor is harmed by the relationship, is known as ___________.

In a tide pool, 15 species of invertebrates were reduced to eight after one species was removed. The species removed was likely a(n) _________

Darwin realized that most species produce many more offspring than is necessary to maintain a constant population. What is the fate of the excess of individuals?

The environment of the world is now in great danger due to ________

India is currently the most populous nation on the planet with a population of about 1.4 billion people.

If two individual birds have different coloration but interbreed and produce viable fertile offspring, they are considered to belong to the same species.

If the flow of energy in an Arctic ecosystem goes through a simple food chain from seaweed to fish to seals to polar bears, then which of the following is true?

Which of the following is NOT among the lines of evidence for the idea that evolution has led to the development of modern species?

The oldest fossils are known from about _____ years ago.