What Is The Difference Between Eukaryotes And Prokaryotes

I was wondering around the internet thinking about what I could write about and it is amazing how your surfing can take you too all sorts of nooks and crannies. I used to love biology but it has been literally decades since I was studying it even at a basic level in high school.

But I came across the question posed in a forum that was, what is the difference between eukaryotes and prokaryotes? I had non idea so I started doing some research and found that the answer was quite interesting and simple, though many websites were complicating the issue.

And because I love simplicity and capturing the crucial elements of life I figured I could do a succinct, simple and yet understandable article about the difference between eukaryotic and prokaryotic life.

At least that will be my approach here today. I hope for your sake I succeed!!

In a nutshell (and that word will become important as you’ll see later), eukaryotes and prokaryotes are used to refer to cells.

However, you can also use the terms eukaryotes and prokaryotes to refer to organisms in general. Let me give you an example. You and I are known as eukaryote organisms. Bacteria are known as prokaryote organisms or prokaryotic organisms.

Knowing this you might assume, and you’d assume correctly, that eukaryotes are more complex cells as the organisms made from eukaryotes are generally bigger and more complex.

In fact when we speak of the domains of life of which there are only 3, we determine them based on their cell type. The 3 domains of life or cellular life forms are archaea, bacteria and eukaryota.

In other words all plants, fungi and animals are eukaryote organisms. So your puppy, your lunch and your grandmother are all eukaryotic.

As you can see eukaryotes only make up one of the three domains, the other 2, the bacteria and archaea are made up of prokaryotic cells. In fact it wasn’t until relatively recently that archaea were seen as separate from bacteria.

So knowing the difference between eukaryotes and prokaryotes is fundamental to our understanding of life at an elementary level.

Knowing now, that eukaryotes are more advanced cells and organisms we might be inclined to a bit of arrogance assuming that we rule the world as eukaryotic organisms. This would be both arrogant and incorrect. In fact, even within the human body prokaryotic cells like microbes and bacteria outnumber human eukaryotic cells by a factor of 10.

At the moment we know that eukaryotes are more complex or “intelligent” if you will than prokaryotes, but why is that and how do we define cells that are eukaryotes vs. prokaryotes so we know the difference.

That brings me back to the word I used earlier. Remember how I said that in a nutshell both eukaryotes and prokaryotes were cells. That word “nutshell” will help us understand the difference between the two.

You see we have to go back to the Greeks. The English words eukaryotes and prokaryotes although just single words in English, actually come from 2 Greek words.

The last part of both eukaryotes and prokaryotes – the “karyote” part – comes from the Greek word “karyon” which means “nut”.

The first part of the word eukaryote – the “eu” part – comes from the Green word “eu” which means “good”. So a eukaryote is a “good nut”.

Bear with me here. When you look at a cell, is there any part of it that looks like a good nut? I think the nucleus does. And remember the nucleus is the brain of the cell and within the nucleus is all the DNA or RNA material that will allow the cell to divide.

And when you look at cells that have nuclei, the nuclei look like nuts don’t they? Good nuts.

In other words, eukaryotes are defined by having a nucleus. Primarily.

Okay, but prokaryotes also have that “karyote” ending which comes from the Greek word for “nut”. Aha, yes, but what about that first part of prokaryote – the “pro” part – well, in Greek “pro” means “before”.

That’s the rub, eukaryotes have “good nuts” or a nucleus, but prokaryotes were developed “before” the “nut” so they don’t have a nucleus. Rather their DNA or RNA is free floating within the prokaryotic cell.

Knowing this important distinction between eukaryotes and prokaryotes you can then make further assumptions that would be correct.

For example, prokaryotes don’t usually have organelles, they don’t have mitochondria (the power plant or stomach of the cell), they don’t have chloroplasts (make food in plant cells) and they don’t divide by mitosis (cell duplication by one division) or meiosis (cell duplication by 2 divisions) which requires a nucleus.

That my friends, in a nutshell ;), is the difference between eukaryotes and prokaryotes.


  1. Nice little article but you should understand that the three domain hypothesis is generally refuted , even by the original creator, and the sum total of evidence does not support the hypothesis. The best, most accurate description eliminated the archaean domain. Molecular evidence suggests the bacteria and archaea are one monophyletic grouping with a billion or so years of lateral gene transfer.

    Just saying.

  2. I appreciate your comment. However, it still appears that however we now start, whether with the tree of life version, we still end up with the 3 major domains as I indicated in the article, which is perhaps still a useful way to understand the difference.

    Even under your evolutionary history of life, the three domains still end up being useful and distinct.

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