The diagram shows a ball resting at the top of a hill. Which statement best describes the energy in this
system?
х
O The potential energy in the system is greatest at X.
The kinetic energy in the system is greatest at X
O Total energy in the system decreases as the ball
moves from X to Y
O Total energy in the system increases as the ball
moves from X to Y

Plants are used for so many things. in your house alone, you can probably look around you and see where plants have been used. for this project, you will identify various uses of plants in your home. directions make a list of objects, products, and any other items around your house where plants were involved in the production of the item. you should have a list of at least twenty items. then respond to the following questions: note: your list of objects and the answers following should be at least 200 words in length. what if plants no longer existed on earth? how would your life be different?

To answer this question, researchers studied populations of the dusky salamander (desmognathus ochrophaeus) living on different mountain ranges in the southern appalachian mountains. the researchers tested the reproductive isolation of pairs of salamander populations by leaving one male and one female together and later checking the females for the presence of sperm. four mating combinations were tested for each pair of populations (a and b)—two within the same population (female a with male a and female b with male b) and two between populations (female a with male b and female b with male a). the proportion of successful matings for each mating combination was measured. for example, when all the matings of a particular combination were successful, the researchers gave it a value of 1; when none of the matings were successful, they gave it a value of 0. then the researchers calculated an index of reproductive isolation that ranged from 0 (no isolation) to 2 (full isolation). the reproductive isolation value for two populations is the sum of the proportion of successful matings of each type within populations (aa + bb) minus the sum of the proportion of successful matings of each type between populations (ab + ba). the table provides data for the geographic distances and reproductive isolation values for 27 pairs of dusky salamander populations.

How energy flows through each level in this energy pyramid. is all the matter and energy from one level transferred to the next level?