Difference Between Animal and Plant Mitosis

Main Difference – Animal Mitosis vs Plant Mitosis

Animal and plant mitosis are two types of reproductive nuclear divisions in animals and plants, respectively. During mitosis, the amount of the genetic material remains as the same. Hence, it increases the number of cells in the body during growth, repair, and regeneration. Mitosis occurs in four major steps; prophase, metaphase, anaphase, and telophase. The main difference between animal mitosis and plant mitosis is that the mitotic spindle in animal mitosis is formed with the help of two centrioles whereas mitotic spindle in plant mitosis is formed without any centrioles. Mitosis is followed by cytokinesis.

Key Areas Covered

1. What is Animal Mitosis
     – Definition, Process, Features
2. What is Plant Mitosis
     – Definition, Process, Features
3. What are the Similarities Between Animal and Plant Mitosis
     – Outline of Common Features
4. What is the Difference Between Animal and Plant Mitosis
     – Comparison of Key Differences

Key Terms: Anaphase, Animal Mitosis, Centrioles, Metaphase, Mitotic Spindle, Plant Mitosis, Prophase, Reproductive Cell Division, Telophase

What is Animal Mitosis

Animal mitosis refers to a part of the cell cycle of animal cells where replicated chromosomes are separated into two, daughter nuclei. This means nuclear division occurs during mitosis. Before entering into the mitotic division, the cell exists in the interphase. Animal mitosis occurs in four major steps: prophase, metaphase, anaphase, and telophase. During prophase, the chromatin in the nucleus is condensed into chromosomes. Since DNA is replicated during interphase, each individual chromosome consists of two sister chromatids. The microtubules, which are involved in maintaining the shape of the cell, are disassembled to form the mitotic spindle. Therefore, the shape of the cell becomes round. The arrangement of the microtubules into the mitotic spindle is done by centrioles, which occur in each pole. The breakdown of the nuclear envelope occurs in prometaphase. Each sister chromatid joins with the spindle fibers. Individual chromosomes are aligned in the cell equator during metaphase.

Figure 1: Animal Mitotic Spindle

During anaphase, each sister chromatid is separated from the centromere and begins to move into the opposite poles of the cell. At this time, the individual sister chromatids are called daughter chromosomes. During telophase, one set of daughter chromosomes has arrived at the each opposite pole of the cell. Therefore, nuclear envelope is formed, surrounding the genetic material in the each pole. Mitosis is followed by cytoplasmic division, which is called cytokinesis. Animal cell cytokinesis occurs by the formation of a cleavage furrow. The spindle apparatus of the animal cell mitosis is shown in figure 1. 

What is Plant Mitosis

Plant mitosis is a part of plant cell division where the replicated chromosomes are separated into two, daughter nuclei. It occurs in four stages, same as animal mitosis. These stages are prophase, metaphase, anaphase, and telophase. During prophase, the chromatin is condensed into individual chromosomes. The formation of the mitotic spindle in plants is different from animal mitotic spindle formation. Plants do not possess microtubules organization centers such as centrioles or spindle pole bodies. Therefore, microtubules are nucleated near the nuclear envelope, forming the mitotic spindle. Metaphase, anaphase, and telophase occur as same as in animal mitosis.

Figure 2: Plant Cell Division

Plant mitosis is followed by cytokinesis. Cytoplasmic division occurs by the formation of a cell plate, separating the two daughter nuclei, which is formed at the end of the telophase. The microtubules of the mitotic spindle are arranged into the phragmoplast, which serves as a scaffold to the formation of the cell plate. The cell plate develops into a new cell wall. The plant cell division is shown in figure 2. 

Similarities Between Animal and Plant Mitosis

• Both animal and plant mitosis occur to increase the number of cells in the body, to repair body tissues, and to regenerate body parts.
• Both processes occur in four major steps: prophase, metaphase, anaphase, and telophase.
• Both animal mitosis and plant mitosis are followed by cytoplasmic division.
• During prophase, the chromosome condensation occurs in both animal and plant mitosis.
• The breakdown of the nuclear envelope occurs in the prometaphase. Individual chromosomes also move the metaphase plate. The spindle attaches to the chromosomes as well.
• Individual chromosomes are arranged on the metaphase plate during metaphase.
• Sister chromatids move towards the opposite poles during anaphase.
• In telophase, the reappearance of the nuclear envelope can be identified.

Difference Between Animal and Plant Mitosis

Definition

Animal Mitosis: Animal mitosis is a part of animal cell division where replicated chromosomes are separated into two, daughter nuclei.

Plant Mitosis: Plant mitosis is a part of plant cell division where replicated chromosomes are separated into two, daughter nuclei.

Shape

Animal Mitosis: The animal cells become rounded before cell division.

Plant Mitosis: The shape of plant cells do not change before cell division.

Induction of the Mitosis

Animal Mitosis: A specific hormone that induces mitosis cannot be identified.

Plant Mitosis: Cytokinin is the type of hormone that induces mitosis.

Centrosome

Animal Mitosis: Centrosomes are formed during animal mitosis.

Plant Mitosis: Centrosomes are not formed during plant mitosis.

Asters in the Mitotic Apparatus

Animal Mitosis: The mitotic apparatus consists of asters.

Plant Mitosis: The mitotic apparatus lacks asters.

Spindle

Animal Mitosis: The spindle that occurs in the animal mitosis is amphiastral.

Plant Mitosis: The spindle that occurs in the plant mitosis is anastral.

Centrioles

Animal Mitosis: Centrioles organize the mitotic spindle during the animal mitosis.

Plant Mitosis: Plant cells lack centrioles.

Spindle at the Cytokinesis

Animal Mitosis: The spindle degenerates before the beginning of cytokinesis.

Plant Mitosis: The spindle exists as the phragmoplast during cytokinesis.

Midbody

Animal Mitosis: A midbody appears during the animal mitosis.

Plant Mitosis: Midbody does not occur in the plant mitosis.

Cytokinesis

Animal Mitosis: Cytokinesis occurs by cleavage in animal mitosis.

Plant Mitosis: Cytokinesis occurs through the formation of a cell plate in plant mitosis.

Occur in

Animal Mitosis: Animal mitosis occurs throughout the body.

Plant Mitosis: Plant mitosis occurs in the meristem.

Conclusion

Animal and plant mitosis are two types of reproductive cell divisions, which are used to increase the cell number in animals and plants, respectively. Both animal mitosis and plant mitosis produce two daughter cells with the same amount of genetic material. Both processes occur through four stages: prophase, metaphase, anaphase, and telophase. Though all stages are same in both animal and plant mitosis, the formation of the mitotic spindle is different. Animal cells contain centrioles, which nucleate the microtubules of the spindle. Since plant cells lack centrioles, the microtubules are nucleated near the nuclear envelope. Therefore, the main difference between animal and plant mitosis is the formation of the mitotic spindle.

Reference:

1.“Animal Cell Mitosis .” CELLS alive!, Available here. Accessed 29 Sept. 2017.
2.“Phases of mitosis.” Khan Academy, Available here. Accessed 29 Sept. 2017.

Image Courtesy:

1. “Spindle apparatus” By Lordjuppiter – Own work (CC BY-SA 3.0) via Commons Wikimedia
2. “Plant cell cycle” By Kelvinsong – Own work (CC BY-SA 3.0) via Commons Wikimedia