For which of the following organelles is the structure and function correctly described?
a) Ribosomes - Membranous vesicles; contain digestive enzymes.
b) Endoplasmic reticulum - Network of interconnected membranes forming sacs and canals; packages protein molecules for secretion.
c) Golgi apparatus - Particles composed of protein and RNA; synthesizes proteins.
d) Mitochondrion - Nonmembranous structure that synthesizes proteins.
e) Nucleus - A bubble that holds secretions.