What causes daytime and nighttime on earth A sun spins in space
B earth revolves around the sun
C earth spins in space
D the sun revolves around earth

How does the study of genetic disorders such as pku biologists understand normal alleles?

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.

Pl which diagram illustrates prophase?