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10 Key Differences Between Mitosis and Meiosis

Posted by Christine Sarikas | Aug 19, 2019 2:00:00 PM

General Education

 

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Getting mitosis and meiosis confused on a biology exam can cost you a lot of points, so it's important to keep these two cellular processes straight. In this guide, we break down mitosis vs meiosis, explain each of the processes, and lay out their similarities and differences so that you’ll be able to easily explain what each process does and how the two differ.

 

What Is Mitosis? What Is Meiosis?

Mitosis and meiosis are both processes of cell division. Organisms are constantly replenishing their cell supply and creating new cells to replace those that are old or damaged, as well as making cells to be used to create new organisms during sexual reproduction.

Mitosis is when a cell divides to create two identical daughter cells. Mitosis occurs in somatic cells (all the cells that aren’t sex cells), and it’s a process critical for producing new cells and keeping the organism alive and healthy. Most cells in the human body only last a few days to a few weeks (an exception is brain cells, which typically last your whole life), so your body must constantly be making new cells through mitosis.

All cells go through a process of formation, growth, division, and eventual death. During mitosis, the parent cell’s nucleus is split to form two sets of chromosomes for each of the new daughter cells. You can learn more about this process by reading our in-depth guide to mitosis.

Meiosis also involves cell division, however, it occurs in far fewer cells in your body. The only cells that go through meiosis are gametes, or sex cells (sperm in men and eggs in women). Meiosis is needed for sexual reproduction, and each cycle of meiosis creates four daughter cells with exactly half the number of chromosomes as the parent cell. During fertilization, two daughter cells (one from each organism reproducing) will combine to create an embryo with a full set of chromosomes. 

 

How Are Mitosis and Meiosis Similar?

As you’ll see in the next section, mitosis and meiosis have many differences, but they follow the same general pattern to complete the cell division process.

The biggest similarity between the two is that they both produce new cells. While the cells they create have some key differences, the end goal is the creation of daughter cells that can be used to either keep the organism alive (mitosis) or help create a new organism during sexual reproduction (meiosis).

Both mitosis and meiosis begin with a single parent cell which eventually splits to form new daughter cells. They also both are preceded by interphase, a period of growth (sometimes lasting up to 90% of the cell’s life) when DNA is synthesized.

During cell replication, mitosis and meiosis follow the same phases: prophase, metaphase, anaphase, and telophase (although meiosis goes through each step twice, while mitosis only goes through each step once). Here’s what happens in each phase:

 

Prophase: 

  • Chromosomes condense into X-shaped structures made up of two identical chromatids
  • Chromosomes/chromatids pair up 
  • Membrane around the cell nucleus dissolves

 

Metaphase:

  • Chromosomes/homologous pairs of chromosomes line up along the center of the cell
  • Mitotic spindle fibers attach to each of the chromosomes

 

Anaphase:

  • Chromosome pairs/sister chromatids are pulled apart by the spindle fibers and move to opposite ends of the cell

 

Telophase:

  • A set of chromosomes gather together at each end of the cell
  • Membrane forms around each chromosome set to create new nuclei

 

Both processes also end with cytokinesis, which is when the cytoplasm of the cell splits when the cell pinches in the middle and eventually separates, forming two new cells.

 

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From left to right: interphase, prophase, metaphase, anaphase, telophase, cytokinesis

 

What Is the Difference Between Mitosis and Meiosis?

Although mitosis and meiosis follow the same basic steps, they have more differences than similarities. Most of these differences relate back to the fact that, although both are needed for cell replication, mitosis and meiosis have different purposes: mitosis replaces body cells with identical copies, while meiosis creates genetically different sex cells that will be used to create an entirely new organism.

Another difference between mitosis and meiosis is that, during mitosis, there is only one cell division, so the cell goes through the steps of prophase, metaphase, anaphase, and telophase once. However, during meiosis there are two cell divisions, and the cell goes through each phase twice (so there’s prophase I, prophase II, etc.).

Additionally, because increasing genetic diversity is a goal of meiosis but not mitosis (where all the daughter cells are identical), during prophase in meiosis, a process called recombination/crossing over occurs. This is when non-sister chromatids of homologous pairs exchange genetic material so that the daughter cells are more genetically diverse from each other.

Here’s a chart summarizing the key differences for mitosis vs meiosis:

 

 
Mitosis
Meiosis
Where it occurs
Occurs in all organisms, except viruses
Only occurs in animals, plants, and fungi
Cells it produces
Creates body/somatic cells
Creates germ/sex cells
Number of cell divisions
One cell division ( 4 stages total)
Two cell divisions (8 stages total)
Prophase length
Prophase is short
Prophase I is longer
Recombination/crossing over
No recombination/crossing over in prophase
Recombination/crossing over of chromosomes during prophase I
Metaphase
During metaphase, individual chromosomes line up on cell’s equator
During metaphase I, pairs of chromosomes line up on cell’s equator
Anaphase
During anaphase, sister chromatids move to opposite ends of the cell
During anaphase I, sister chromatids move together to the same cell pole.
During anaphase II, sister chromatids are separated to opposite ends of the cell
Number of cells created
End result: two daughter cells
End result: four daughter cells
Ploidy
Creates diploid daughter cells
Creates haploid daughter cells
Genetics
Daughter cells are genetically identical
Daughter cells are genetically different



Summary: Compare and Contrast Mitosis and Meiosis

Below is a mitosis and meiosis Venn Diagram that summarizes all the key mitosis vs meiosis similarities and differences. On the left side of the diagram, you can see the key features of mitosis, on the right are the key features of meiosis, and where the two circles overlap is where their similarities are listed.

 

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What's Next?

If you want to better understand what DNA is, you need to know about nucleotides. In our guide to nucleotides, we explain what they are and how they make up DNA.

Vacuoles are a key organelle in cells. Learn everything you need to know about vacuoles, as well as why they're so different in plant vs animal cells, by reading our guide to vacuoles

What are the most important science classes to take in high school? Check out our guide to learn all the high school classes you should be taking.

 

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Christine Sarikas
About the Author

Christine graduated from Michigan State University with degrees in Environmental Biology and Geography and received her Master's from Duke University. In high school she scored in the 99th percentile on the SAT and was named a National Merit Finalist. She has taught English and biology in several countries.



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