This pattern includes___ extinction witch tends to not disturb ecosystems as well as a ___ extinction in which ecosystems change drastically

The correct answers are:

- background extinction;

The background extinction is an extinction that occurs naturally, and small number of species are affected by it in certain periods. It occurs as a natural way of the evolution of the species.

- mass extinction;

The mass extinction occurs after a massive natural catastrophe that influences the whole planet, or big portion of it. In this type of extinction, the ecosystem changes dramatically because the majority of the species die out in a very short space of time.