Answer:
Endoskeleton
Explanation:
An internal skeleton is called an endoskeleton, which is what vertebrates have. A sponge endoskeleton consists of short, sharp rods called spicules
Spicules are made of silica, calcium carbonate, etc.
The food chains make up the food webs
Answer:
The ecosystems are different
Explanation:
Every ecosystem needs most of the types, such as producers and herbivours, but different animals need different climates, such as cacti need deserts, yet fish need water, they can't( Or shouldn't ) Be in the same ecosystem due to thier needs.
It would b B.physically because solution is a mixture and mixture is formed by physical change not by chemical