8. Rich genetic variation signals a diverse biosphere. Explain the importance of genetic variation in the face of ecological disturbances, and give two examples of ecological disturbances that may affect a
population. (4 points)

Why are scientists concerned about the depletion of the ozone levels in the stratosphere?

2. cheryl hears a new song on the radio every day during the week on her commute to work. surprisingly, when the song comes on at a party on saturday night, she knows most of the words without trying. describe the three ways that we use cognition to learn without reinforcement. which type of cognitive learning without reinforcement best explains how cheryl knew the song lyrics? explain your answer.

This is an active transport mechanism by which cells pump sodium and potassium ions against the concentration gradient