Bacteria are the best creatures on the planet. They lived on this planet for two billion years before the first eukaryotes and, during that time, evolved into millions of different species.
Size and Shape
Bacteria are small to the point that they must be seen with a magnifying lens. At the point when seen under the magnifying lens, they have three particular shapes.
Bacteria can be identified and classified by their shape:
Bacilli are rod-shaped.
Cocci are sphere-shaped.
Spirilli are spiral-shaped.
Similarities to Eukaryotes
Like eukaryotic cells, bacterial cells have:
1.Cytoplasm, the fluid inside the cell.
2.A plasma or cell membrane, which acts as a barrier around the cell.
3.Ribosomes, in which proteins are put together.
4.DNA. By contrast though, bacterial DNA is contained in a large, circular strand. This single chromosome is located in a region of the cell called the nucleoid.
The Cell Wall
Bacteria are surrounded by a cell wall consisting of peptidoglycan. This complex molecule consists of sugars and amino acids.
Some bacteria also have tail-like structures called flagella. Flagella help bacteria move.
Bacteria can be ordered by their shape, including bacilli (bars), cocci (circles), and spirilli (spirals) Bacteria resemble eukaryotic cells in that they have cytoplasm, ribosomes, and a plasma film.
Features that distinguish a bacterial cell from a eukaryotic cell include the circular DNA of the nucleoid, the lack of membrane-bound organelles, the cell wall of peptidoglycan, and flagella.