Anatomy
There are two types of cells: eukaryotic and prokaryotic. Prokaryotic cells are usually independent, while eukaryotic cells are often found in multicellular organisms.
| Prokaryotes | Eukaryotes | |
|---|---|---|
| Typical organisms | bacteria, archaea | protists, fungi, plants, animals |
| Typical size | ~ 1–10 µm | ~ 10–100 µm (sperm cells, apart from the tail, are smaller) |
| Type of nucleus | nucleoid region; no real nucleus | real nucleus with double membrane |
| DNA | circular (usually) | linear molecules (chromosomes) with histone proteins |
| RNA-/protein-synthesis | coupled in cytoplasm | RNA-synthesis inside the nucleus protein synthesis in cytoplasm |
| Ribosomes | 50S+30S | 60S+40S |
| Cytoplasmatic structure | very few structures | highly structured by endomembranes and a cytoskeleton |
| Cell movement | flagella made of flagellin | flagella and cilia containing microtubules; lamellipodia and filopodia containing actin |
| Mitochondria | none | one to several thousand (though some lack mitochondria) |
| Chloroplasts | none | in algae and plants |
| Organization | usually single cells | single cells, colonies, higher multicellular organisms with specialized cells |
| Cell division | Binary fission (simple division) | Mitosis (fission or budding) Meiosis |
Read more about this topic: Cell (biology)
Famous quotes containing the word anatomy:
“Man is a shrewd inventor, and is ever taking the hint of a new machine from his own structure, adapting some secret of his own anatomy in iron, wood, and leather, to some required function in the work of the world.”
—Ralph Waldo Emerson (1803–1882)
“I love to see, when leaves depart,
The clear anatomy arrive,”
—Roy Campbell (1902–1957)
“But a man must keep an eye on his servants, if he would not have them rule him. Man is a shrewd inventor, and is ever taking the hint of a new machine from his own structure, adapting some secret of his own anatomy in iron, wood, and leather, to some required function in the work of the world. But it is found that the machine unmans the user. What he gains in making cloth, he loses in general power.”
—Ralph Waldo Emerson (1803–1882)