The answer that you are looking for is Chloroplast.
The reason why this is the answer is because the Chloroplast allows plants to make food with the help of sunlight.
I hope this helped :)
Because if the new species is better at doing whatever the original species does, the original species can die because they are outcompeted by the new species, and because the new species is better, they can cause a further decline of for example the food supply that they're outcompeting the original species for. This can cause problems in the entire food web/ecosystem
It can either be reflected or radiated back into space, it can get absorbed by the atmosphere, or it can reach the ground.
Good luck :)
I would say disruptive selection, because the sudden eruption of the volcano disrupted the circumstances of the lizards, allowing the black ones to survive better because of camouflage against the black rock.
Hope this helps!