Both plant and animal cells contain-

a. a cell membrane, cell wall, and a nucleus.

b. a cell membrane, cytoplasm, and a nucleus.

c. mitochondria, a cell membrane, and chloroplasts.

d. mitochondria, a cell wall, and chloroplasts.

There are specialized producers that live in warm water vents deep in the ocean. these producers do not per-form from photosynthesis, but instead perform a similar process with iron and other chemicals. why do you think these producers use this process instead of photosynthesis?

The circles, or orbits, for electrons are called energy levels. each level can hold only a certain number of electrons. add electrons to each level until you can't add any more. how many electrons can each level hold?

How do cells grow and reproduce to maintain homeostasis?