Your pupils dilate in the dark and contract when exposed to bright light. If your pupil's diameter increases from 1 to 3mm, how many more photons per second will you be able to collect? twice as many

three times as many

nine times as many

you'll collect the same number of photons

What is thought to have caused the mass extinction at the end of the cretaceous period?

The image below shows a common blood pressure gauge. what does this device do? a. measures the level of oxygen present in the blood b. measures the pressure of blood when the lungs expand and compress c. measures the electrical activity of the heart d. measures the pressure of blood when the heart contracts and relaxes

Asquirrel population lives in an area. over many years, a river in that area grows wider and stronger, eventually forming a canyon. the squirrel populations on the two sides of the canyon can no longer mate with each other and ultimately form distinct species. this is an example of