Prokaryotes - Missing a NucleusIf you're looking to learn about cells with a nucleus, this is the wrong place. Prokaryotes do not have an organized nucleus. Their DNA is kind of floating around the cell. It's clumped up, but not inside of a nucleus. If you want to learn about cells with a nucleus, look for information on eukaryotes. And, once again, a prokaryote is a single cell or organisms that does NOT have organized nuclei.
Can You Exist Without a Nucleus?You can't, but they can. What can you do without a nucleus? You can do a whole lot. Most prokaryotes are bacteria and bacteria can do amazing things. Although they are very simple organisms, they are found everywhere on the planet. Some scientists even think that they may be found on other planets (maybe even Mars). Some places you can find bacteria every day are in your intestines, a cup of natural yogurt, or a bakery. Prokaryotes are the simplest of simple organisms. Here's the checklist.
(1) Prokaryotes have no organized nucleus. Like we said, the DNA is clumped in an area but there is no organized nucleus with a membrane.
(2) Prokaryotes do not usually have any organelles. They will probably have ribosomes inside of their cells, but ribosomes are not technically considered organelles. No chloroplasts. No mitochondria. No nucleus. Not much at all.
(3) Prokaryotes are very small. Because they don't have all of the normal cell machinery, they are limited in size. As always in biology, there are exceptions, but generally, prokaryotes are very small (compared to other cells). Mind you, compared to a virus they are big, but next to an amoeba, tiny.
(4) Prokaryotes don't have mitosis or meiosis like other cells. Scientists don't really have a good way of describing how they duplicate, but it's not through normal means. Check out the bacteria tutorial to get an idea.
Or search the sites for a specific topic.
- Protozoa I
- Protozoa II
- Good Microbes
- Bad Microbes
- Humans and Microbes
- More Topics
Science Nation: Extreme Microbes (US-NSF Video)
Useful Reference MaterialsEncyclopedia.com: