How was the theory of evolution developed over time?

What does the positioning of transcription factors determine?

The climate on the leeward side of a mountain differs from that on the windward side mostly in

Abird flies by moving its wings up and down. which two systems are most directly responsible for the movement of a bird's wings? a. skeletal and muscular systems b. respiratory and muscular systems c. skeletal and digestive systems d. respiratory and digestive systems