Bell Ringer 1. Define a population . 2. Evolution is driven by random occurrences. List four examples of random occurrences that can lead to evolution

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.