Not only does sediment spread horizontality and from youngest (top) to oldest (bottom), it also continues to spread flat in all directions until it either runs out of material—pinches off—or hits a barrier. This is known as the . science

For 50 points populations within ecosystems can be separated into categories—producers, consumers, and decomposers. these categories represent a. the fossil records of organisms. b. the reproductive methods of organisms. c. the body plans of organisms. d. the functions that organisms serve.