The cenozoic era is best described as the era in which
a. multicellular life diversified.
b. a mass extinction event occurred.
c. dinosaurs emerged.
d. mammals began to dominate the land.

fertilization is the union of an egg and a sperm cell i believe.

within these regions are all the major types of biomes in the world. a biome is a community of animals and plants spreading over an extensive area with a relatively uniform climate. some diverse biomes represented in north america include desert, grassland, tundra, and coral reefs.