Eukaryotes and prokaryotes
Bacteria are amongst the simplest of organisms - they are made of single cells. Their cell structure is simpler than the cells of animals, plants and fungi.
Cells of animals, plants and fungi are called Description of a cell which has a nucleus. Eukaryotic cells also have other structures in the cytoplasm which have membranes around them..
Cells of bacteria are called Description of a cell which does not have a nucleus - the DNA is free in the cytoplasm..
Eukaryotic cells
The two types of cell compared:
| Feature | Eukaryotic cell | Prokaryotic cell |
| Size | Most are 5鈥100 渭m | Most are 0.2鈥2.0 渭m |
| Outer layers of cell | Cell membrane. Surrounded by cell wall in plants and fungi. | Cell membrane. Surrounded by cell wall. |
| Cell contents | Cytoplasm. Cell organelles include mitochondria, chloroplasts in plants and ribosomes. | Cytoplasm. Ribosomes present. There are no mitochondria or chloroplasts. |
| Genetic material | DNA in a nucleus. Plasmids are found in a few simple eukaryotic organisms. | DNA is a single molecule that is found free in the cytoplasm. Additional DNA is found on one or more rings called plasmids. |
| Type of cell division | Mitosis | Binary fission |
| Feature | Size |
|---|---|
| Eukaryotic cell | Most are 5鈥100 渭m |
| Prokaryotic cell | Most are 0.2鈥2.0 渭m |
| Feature | Outer layers of cell |
|---|---|
| Eukaryotic cell | Cell membrane. Surrounded by cell wall in plants and fungi. |
| Prokaryotic cell | Cell membrane. Surrounded by cell wall. |
| Feature | Cell contents |
|---|---|
| Eukaryotic cell | Cytoplasm. Cell organelles include mitochondria, chloroplasts in plants and ribosomes. |
| Prokaryotic cell | Cytoplasm. Ribosomes present. There are no mitochondria or chloroplasts. |
| Feature | Genetic material |
|---|---|
| Eukaryotic cell | DNA in a nucleus. Plasmids are found in a few simple eukaryotic organisms. |
| Prokaryotic cell | DNA is a single molecule that is found free in the cytoplasm. Additional DNA is found on one or more rings called plasmids. |
| Feature | Type of cell division |
|---|---|
| Eukaryotic cell | Mitosis |
| Prokaryotic cell | Binary fission |
A group of organisms called A type of single-celled microorganisms. They are similar to bacteria, and are usually found in extreme conditions such as hot springs. are also prokaryotic.