The first observations of intracellular structures that probably represent mitochondria were published in the 1840s.

Some plants can take up silica in the soil, whereupon it is deposited within different intracellular and extracellular structures of the plant.

This process, called 'self-assembly', can explain the formation of some intracellular structures, such as the ribosomes described on page 16.

At least some prokaryotes also contain intracellular structures that can be seen as primitive organelles.

Some species of vascular plants also contain intracellular structures called oil bodies.

As they are prokaryotes, bacteria do not tend to have membrane-bound organelles in their cytoplasm and thus contain few large intracellular structures.

Instead, the chromosome and perhaps ribosomes are the only easily observable intracellular structures found in all bacteria.

They do exist, however, specialized groups of bacteria that contain more complex intracellular structures, some of which are discussed below.

In most bacteria the most numerous intracellular structure is the ribosome, the site of protein synthesis in all living organisms.

His body exhibits the characteristic intracellular structures of one who is 1O.2.