Many chemicals are used to kill insects and protect animals. how could the removal of insects upset the balance of the ecosystem?

Animals that rely on insects for food would die.

Explanation: This is because without thir main food source, the carrying capacity would lower, therefore, lowering the possible population.

answer:

convection currents in the magma drive plate tectonics. heat generated from the radioactive decay of elements deep in the interior of the earth creates magma (molten rock) in the aesthenosphere. the aesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the earth that extends to 2900 km.