Here are some things that interfer with the ecosystem (highways, driving cars, fossil fuel, cities, farms, deforestation, over hunting, over fishing and plastics)
This is because of B. Their cells are in direct contact with the environment.
It pollutes the oceans waterd and can cause harm to the animals and can affect the the animals population which can make harm to the food chain
-cephalization-bilateral symmetry
(Faster directional movement)