Final answer:
Primitive meteorites, which originate from undifferentiated bodies, are composed of materials that have not experienced significant heat or pressure and include carbonaceous meteorites that contain complex organic molecules.
Step-by-step explanation:
The type of meteorites that come from undifferentiated bodies are known as primitive meteorites. These meteorites have not been altered by significant heat or pressure since their formation and offer valuable insights into the early history of the solar system. Primitive meteorites mainly come from the group of carbonaceous meteorites, including famous examples such as the Allende and Murchison meteorites.
These contain organic molecules and sometimes chemically bound water, and many are depleted in metallic iron, differentiating them from other meteorites that stem from bodies that have undergone differentiation and separation of materials by density.