1.3 Prokaryotic organism features

Describe the common features of prokaryotic organisms such as bacteria.
Bacteria are microscopic and single-celled. They have a cell wall, cell membrane, cytoplasm and plasmids, but no nucleus; their DNA forms a circular chromosome. Some photosynthesise, but most feed on living or dead organisms. Examples include rod-shaped Lactobacillus bulgaricus, used to make yoghurt, and spherical Pneumococcus, which causes pneumonia.