It is pretty simple which part are u confused by?
Explanation:
A keystone species is an organism that helps define an entire ecosystem. By keeping populations of mussels and barnacles in check, this sea star helps ensure healthy populations of seaweeds and the communities that feed on them—sea urchins, sea snails, limpets, and bivalves.
<span>food chains follow just one path of energy as animals find food.
</span>food webs show how plants and animals are involved in ways to help them all survive.
Use the pH color scale. It shows acidity level of both acids and bases. You dip one of the pH strips into whatever liquid you choose, and then compare the new color of the pH strip to the colors on the scale. This will tell you the level of acidity. pH scale can be found below. As you can see, the brighter colors are more acidic than the darker and duller colors.