Bacteria cell Types
All animals and plants are made of cells. Animal and plant cells have features in common, such as a nucleus, cytoplasm, cell membrane, mitochondria and ribosomes. Plant cells also have a cell wall, and often have chloroplasts and a permanent vacuole. Note that cells may be specialised to carry out a particular function.
We use microscopes to see very tiny structures such as cells.
Bacterial cells are much smaller than plant or animal cells. They were first seen under a microscope by Anton van Leeuwenhoek in 1676. As microscopes have improved, scientists have come to understand bacterial cell structure better.
Using electron microscopes we now know that bacteria have a cell wall. This is similar to a plant cell wall but is more flexible. Bacteria do not have a nucleus. They do have two types of DNA – plasmid and chromosomal. The chromosomal DNA carries most of the genetic information. Plasmid DNA forms small loops and carries extra information. Some bacteria have a flagellum – a whip like tail. This helps the bacteria to move itself along. When we talk about these flagellum tails in multiple bacteria, we call them flagella.