Given a scientific passage and an answer, generate a question for the given answer.

[Q]: Passage: Virtually all animals have internal digestion of food. Animals consume other organisms and may use special tissues and organs to digest them. (Other heterotrophs, such as fungi, absorb nutrients directly from the environment. ). Answer: internal
[A]: What sort of digestion do animals engage in?

[Q]: Passage: Sources of voltage include electric generators and cells. Electric generators change kinetic energy to electrical energy. Chemical cells change chemical energy to electrical energy, and solar cells change solar energy to electrical energy. Answer: electrical
[A]: Electric generators change kinetic energy to what type of energy?

[Q]: Passage: There are two types of endoplasmic reticulum. They are called rough endoplasmic reticulum (RER) and smooth endoplasmic reticulum (SER). Both types are shown in Figure below . Answer: rough & smooth
[A]:
What are the two types of endoplasmic reticulum?