Nucleus Double membrane surrounding the chromosomes and the nucleolus.
Pores allow specific communication with the cytoplasm.
The nucleolus is a site for synthesis of RNA making up the ribosome. Mitochondria Surrounded by a double membrane with a series of folds called cristae. Functions in energy production through metabolism. Contains its own DNA, and is believed to have originated as a captured bacterium. Responsible for photosynthesis, the trapping of light energy for the synthesis of sugars.