The sphincter is a of muscle at an opening.
a. strip
b. pack
c. ring
d. band
e. network

Which describes how weathering and erosion are different? weathering is caused by water. erosion is caused by wind and ice. erosion transports sediments. weathering is a natural process.

Which identifies the main purpose of biological taxonomy?

Why do leaves change color in the fall? green pigments break down and no longer mask the color of chlorophyll. chlorophyll breaks down and no longer masks the colors of other pigments. red- and yellow-colored pigments grow and mask green-colored chlorophyll. green-colored chlorophyll breaks down and turns red and yellow.