What is the Difference Between Cleavage and Cell Division

The main difference between cleavage and cell division is that the cleavage is the cytoplasmic division which follows nuclear division whereas the cell division is the process in which the parent cell divides into two daughter cells. 

Cleavage and cell division are two events of the cell cycle. They are responsible for the production of daughter cells from a parent cell. Furthermore, cleavage is also called cytokinesis while the two steps of cell division are karyokinesis and cytokinesis.

Key Areas Covered

1. What is Cleavage
     – Definition, Stages, Importance
2. What is Cell Division
     – Definition, Stages, Importance
3. What are the Similarities Between Cleavage and Cell Division
     – Outline of Common Features
4. What is the Difference Between Cleavage and Cell Division
     – Comparison of Key Differences

Key Terms

Cell Division, Cleavage, Cytokinesis, Meiosis, Mitosis

What is Cleavage

Cleavage is the division of the cytoplasm of the parent cell between the two daughter nuclei produced by the nuclear division. It is the second step of the cell division and is responsible for the separation of the parent cell into two daughter cells. Moreover, it starts during the telophase, the final stage of the nuclear division. Also, cytokinesis is the terms that describes the cytoplasmic division of all types of cells including animal cells, plant cells, and prokaryotic cells. However, this process varies according to the cell type. Cleavage mainly refers to cytokinesis in animals.

Figure 1: Cleavage

Animal as well as many unicellular eukaryotic cytokinesis occurs through four steps: initiation, contraction, membrane insertion, and completion.

1. Initiation – Formation of the cleavage furrow on the cell surface by the formation of the contractile ring, composing of actin filaments, myosin II filaments, and many structural and regulatory proteins. The contractile ring forms during early anaphase
2. Contraction – Contraction of the contractile ring to constrict the cell into two
3. Membrane insertion – Formation of a membrane adjacent to the contractile ring by the fusion of intracellular vesicles
4. Completion – Further contraction of the contractile ring and the formation of the membrane cause the completion of the cleavage, completely separating the two daughter cells

During embryogenesis, cleavage refers to the rapid mitotic divisions of the zygote, forming the blastocyst, a multicellular structure. It is characterized by the absence of the growth of the daughter cells; hence, cleavage is involved in the distribution of the cytoplasm of the zygote among the cells of the blastocyst.

What is Cell Division

Cell division is the splitting of a parent cell into two or more daughter cells. It is an event of the cell cycle and it follows the G₂ phase. Also, there are two types of cell divisions in cells. Namely, they are the mitosis and the meiosis. Each type of cell division occurs through two steps; nuclear division, which follows cytokinesis.

Mitosis is responsible for asexual reproduction since it produce new cells, which can replace the old, lost or damaged cells. Furthermore, the daughter cells produced by mitosis contain the exact amount of chromosomes as the parent cell. The four stages of the mitosis are prophase, metaphase, anaphase, and telophase.

1. Prophase – Condensation of the chromosomes and the formation of the mitotic spindle
2. Metaphase – Aligning of the chromosomes in the equatorial plate
3. Anaphase – Constriction of the microtubules of the mitotic spindle to separate the sister chromatids
4. Telophase – Sister chromatids are pulled towards the opposite poles of the cell
   

   Figure 2: Cell Division

On the other hand, meiosis is responsible for the production of gametes used in sexual reproduction. Therefore, the daughter cells produced by meiosis contain a half of the chromosomes as their parent cell. The two stages of meiosis are meiosis I and meiosis II. Moreover, both stages consist of four substages, prophase, metaphase, anaphase, and telophase.

1. Meiosis I – Separation of the homologous chromosomes between two daughter cells
2. Meiosis II – Separation of the sister chromatids between two daughter cells

Similarities Between Cleavage and Cell Division

• Cleavage and cell division are two event of the cell division.
• Also, both are responsible for the production of daughter cells from a parent cell.

Difference Between Cleavage and Cell Division

Definition

Cleavage refers to the act or state of splitting or dividing of a cell, particularly during the telophase of (animal) cell division while cell division refers to the process by which a parent cell divides into two or more daughter cells. Thus, this is the fundamental difference between cleavage and cell division.

Occurrence

Another difference between cleavage and cell division is that the cleavage occurs only in animal cells while cell division occurs in both animal and plant cells.

Significance

In addition, cleavage is also called cytokinesis in animal cells while the two steps of cell division are kayokinesis and cytokinesis.

Events

The division of the cytoplasm of the parent cell between the two daughter nuclei occurs during the cleavage while the division of the parent nucleus into two daughter nuclei and then, the division of the cytoplasm occur during cell division. This is the main difference between cleavage and cell division.

Consequence

Moreover, cleavage follows nuclear division while cell division follows G₂ phase of the cell cycle. This is a major difference between cleavage and cell division.

Components

Furthermore, actin filaments, myosin filaments, and contractile ring are involved in cleavage while the mitotic spindle made up of microtubules is involved in the nuclear division.

In Embryology

Cleavage refers to the rapid cell division of the zygote by mitosis while mitosis is the type of cell division responsible for the cleavage.

Conclusion

Cleavage is the cytokinesis of animal cells. It involves the division of the cytoplasm between the two daughter nuclei formed during the nuclear division. On the other hand, cell division is the split of a parent cell into daughter cells. The two types of cell division are mitosis and meiosis. In brief, the main difference between cleavage and cell division is the process of each event.

Reference:

1. “Cleavage Furrow – Definition and Function.” Biology Dictionary, Biology Dictionary, 28 Apr. 2017, Available Here
2. “The Cell Cycle, Mitosis and Meiosis.” Virtual Genetics Education Centre, University of Leicester, 17 Aug. 2017, Available Here

Image Courtesy:

1. “Telophase” By Kelvinsong – Own work (CC BY 3.0) via Commons Wikimedia  
2. “Cell cycle with images” By WikiES – Own work (CC BY-SA 4.0) via Commons Wikimedia