How Is Mitosis And Meiosis Similar

Your body is made up of trillions of cells that all originate from just one—a fertilized egg. The massive multiplication of cells after conception is possible thanks to cell division, which occurs when one cell splits into two. Cell division not only enables growth but also replaces damaged or dead cells and makes reproduction possible. There are two kinds of cell division: mitosis and meiosis.

What’s the Difference?

Mitosis produces two genetically identical “daughter” cells from a single “parent” cell, whereas meiosis produces cells that are genetically unique from the parent and contain only half as much DNA. Most cells in the body regularly go through mitosis, but some do so more often than others. For instance, those that line the stomach replace themselves after just a few days because they’re subjected to strong digestive acids. In contrast, liver cells may wait up to a year to replace themselves. There are also a few types that last a lifetime without dividing, such as some nerve cells and cells that make up the lens of the eye. Meiosis occurs only in the production of sperm and egg cells for sexual reproduction.

The Phases of Cell Division

Before either mitosis or meiosis occurs, cells go through a preparatory process called interphase, where they grow and make a copy of their genetic information.

Mitosis has six phases apart from interphase. The first five phases divide the nucleus and its genetic information in half, while the final step splits the entire parent cell into two identical daughter cells. The phases of mitosis are:

Prophase: Chromosomes, which contain genetic information, condense and prepare to attach to the spindle—a cellular machine that moves chromosomes during cell division.
Prometaphase: The nuclear membrane breaks apart, the spindle forms, and chromosomes attach to its strong, hollow fibers.
Metaphase: Chromosomes align along the spindle’s center.
Anaphase: Chromosomes pull apart and move toward the spindle’s poles, which also move apart.
Telophase: New nuclear envelopes form around the two separated sets of chromosomes.
Cytokinesis: Cells divide.

Meiosis has similar steps to mitosis but with two sets of divisions. The first division results in two cells that each have two sets of chromosomes, like in mitosis. The second division creates four cells that each contain one set of chromosomes, because the genetic information isn’t copied a second time. One unique feature of meiosis, which takes place during the first round of prophase (prophase I), is a process called crossing over. DNA is mixed between matching chromosomes from the different parents, increasing the genetic diversity.

NIGMS-Funded Cell Division Research

Many scientists who are supported by NIGMS study cell division. Some of these researchers are investigating how cells maintain normal cell division through aligning and separating chromosomes via the spindle during mitosis and meiosis, prevent genetic errors from being introduced during crossing over in meiosis, and decide to either grow and divide or enter a resting phase, which is important in understanding diseases caused by excessive or insufficient cell division.

From an academic perspective, understanding the difference between mitosis and meiosis is crucial. Read on to explore what is mitosis and meiosis, significant similarities and differences between the two:

Difference Between Mitosis And Meiosis

In single-celled organisms, cell reproduction gives rise to the next generation. In multicellular organisms, cell division occurs not just to produce a whole new organism but for growth and replacement of worn-out cells within the organisms. Cell division is always highly regulated and follows a highly orchestrated series of steps. The term cytokinesis refers to the division of a cell’s cytoplasm, while mitosis and meiosis refer to two different forms of nuclear division. Mitosis results in two nuclei that are identical to the original nucleus. Meiosis, on the other hand, results in four nuclei, each having half the number of chromosomes of the original cell. In animals, meiosis only occurs in the cells that give rise to the sex cells (gametes), i.e., the egg and the sperm.

Differences Between Mitosis and Meiosis

The important difference between mitosis and meiosis are mentioned below:

Mitosis involves one cell division, while meiosis involves two successive cell divisions.
Mitosis results in two daughter cells, while meiosis results in four daughter cells.
Mitosis results in diploid daughter cells (chromosome number remains the same as parent cell), while meiosis results in haploid daughter cells (chromosome number is halved from the parent cell).
Mitosis daughter cells are genetically identical, while meiosis daughter cells are genetically different.
Mitosis occurs in all organisms except viruses, while meiosis occurs only in animals, plants, and fungi.
Mitosis creates all body cells (somatic) apart from the germ cells (eggs and sperm), while meiosis creates germ cells (eggs and sperm) only.

Similarities Between Mitosis and Meiosis

Both mitosis and meiosis take place in the cell nuclei, which can be observed under a microscope. Both mitosis and meiosis involve cell division. Both the processes occur in the M-phase of the cell cycle. In both cycles, the typical stages are prophase, metaphase, anaphase, and telophase. In both cycles, synthesis of DNA takes place.

Conclusion

The difference between Mitosis and Meiosis is quite apparent. They are two very different processes that have two different functions. Meiosis is required for genetic variation and continuity of all living organisms. Mitosis, on the other hand, is focused on the growth and development of cells. Meiosis also plays an important role in the repair of genetic defects in germline cells.

Frequently Asked Questions

Q1: What is mitosis?

Mitosis is a form of cell division where the cell splits into two, each identical to the original cell.

Q2: What is Meiosis?

Meiosis is a type of cell division that results in four cells, each having half the number of chromosomes of the original cell.

Q3: List out the difference between mitosis and meiosis

The difference between mitosis and meiosis are as follows:

Mitosis was discovered by Walther Flamming, while meiosis was discovered by Oscar Hertwig.
Cytokinesis occurs only in telophase during mitosis, while it occurs in Telophase 1 and telophase 2 during meiosis.
The primary function of mitosis is general growth and repair. It is also used for cell reproduction.
Tetrad formation is not observed in mitosis. Tetrad formation is observed in meiosis.
Meiosis, on the other hand, aims to provide genetic diversity through sexual reproduction.
Asexual mode of reproduction is observed for mitosis. Sexual mode of reproduction is observed for meiosis.

Q4: State a few similarities between mitosis and meiosis.

The similarities between mitosis and meiosis are as follows:

Mitosis and meiosis take place in the cell nuclei.
Both involve cell division.
Both the processes occur in the M-phase of the cell cycle.
In both cycles, the stages are common – prophase, metaphase, anaphase, and telophase.
Synthesis of DNA occurs in both.