Eukaryotic cells and prokaryotic cells are very different from each other. They belong to three main groups of life: Bacteria, Archaea, and Eukarya.
Key Differences:
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Cell Structure:
- Eukaryotic Cells: These cells have a more complicated setup. They contain special parts, called organelles, that are surrounded by membranes. One of the most important organelles is the nucleus, which holds the cell’s DNA. Examples of eukaryotic cells are found in plants, animals, fungi, and protists.
- Prokaryotic Cells: These cells are simpler. They do not have a nucleus or membrane-bound organelles. Instead, their DNA is floating around in the cell fluid. Bacteria and Archaea are examples of prokaryotic cells.
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Size:
- Eukaryotic Cells: These cells are usually larger, ranging from 10 to 100 micrometers.
- Prokaryotic Cells: They are much smaller, typically between 0.1 and 5.0 micrometers.
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Genetic Material:
- Eukaryotic Cells: The DNA in these cells is organized into straight pieces called chromosomes. For example, humans have 46 chromosomes.
- Prokaryotic Cells: Their DNA is shaped like a circle and usually has just one chromosome. They can also have small circles of DNA called plasmids.
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Reproduction:
- Eukaryotic Cells: These cells reproduce using a complex process called mitosis (which is asexual) and meiosis (which is sexual).
- Prokaryotic Cells: They mainly reproduce by a simple method called binary fission, where one cell divides into two identical cells.
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Ribosome Size:
- Eukaryotic Cells: The ribosomes in these cells are larger, called 80S.
- Prokaryotic Cells: Their ribosomes are smaller, known as 70S.
Classification Brief:
- Domain Bacteria: This group has a large number of prokaryotic organisms—about 5,000 different types are known.
- Domain Archaea: These are also prokaryotic but are different from bacteria. About 1,000 types are known, and they often live in extreme places.
- Domain Eukarya: This group includes eukaryotic organisms, which are usually more complex and made up of many cells. It is estimated that there are about 8.7 million species in this domain across all kinds of life.
In short, knowing the differences between eukaryotic and prokaryotic cells is important. It helps us understand how life is organized, how these cells function, and how they evolved over time.