What is a mutagen? a environmental factors that cause mutations
b inherited mutations
C factor that immediately kills the organism
d cancer-causing agent

Compare and contrast region e in the illustration above with region d. describe the physical characteristics of each region.

What function does the limb sever in each animal? how are the limb bones of the four animals similar? based on these similarities what can be inferred about the evolution of the four animals.

When fossil fuels are burned, carbon dioxide is released. how does this gas impact the environment?