Which of the following about the food chain is CORRECT: A) A food chain always contains three trophic levels.

B) Lions are on the first trophic level in their food chain.

C )Usually, the higher an animal is in it's food chain, the bigger and more powerful it is.

D) A food chain is also known as a food web.

Based on the observation that only male crickets produce a song, you hypothesize that a male's song is a form of communication to potential mates. you set up a simple experiment to test this hypothesis. in the laboratory, you place a male snowy tree cricket in enclosure a, which is adjacent to enclosureb. in enclosure b, you place other insects, one at a time, and observe their responses to the male's song. the enclosures are designed so that the two insects being tested cannot see or smell each other, but sound is transmitted from enclosure a to enclosureb.