Cytokinesis

Definition

Cytokinesis is the process where the cytoplasm of a parental cell divides to form two daughter cells, completing cell division. It is crucial for ensuring that each daughter cell receives an adequate amount of cellular components and organelles, and it typically follows mitosis or meiosis. This process is essential in both the formation of early embryonic structures and the production of gametes, affecting overall organism development and reproduction.

5 Must Know Facts For Your Next Test

1. Cytokinesis can differ between animal and plant cells; animal cells form a cleavage furrow while plant cells create a cell plate.
2. In animal cells, the contractile ring composed of actin filaments plays a key role in forming the cleavage furrow during cytokinesis.
3. Cytokinesis ensures that each daughter cell has an equal distribution of organelles, cytoplasm, and genetic material.
4. The timing of cytokinesis is tightly regulated and is usually coordinated with the completion of mitosis or meiosis.
5. Errors during cytokinesis can lead to multinucleated cells or unequal distribution of cellular contents, potentially resulting in developmental issues or diseases.

Review Questions

• Explain how cytokinesis contributes to the development of early embryonic structures.
  • Cytokinesis plays a pivotal role in the development of early embryonic structures by ensuring that each daughter cell receives equal parts of the cytoplasm and organelles after cell division. This equal distribution is crucial for normal growth and differentiation of embryonic cells, enabling them to develop into various tissues and organs. Without proper cytokinesis, cells might end up with varying sizes and numbers of organelles, leading to imbalances that can affect the entire organism's development.
• Compare and contrast the mechanisms of cytokinesis in animal cells versus plant cells.
  • In animal cells, cytokinesis occurs through the formation of a cleavage furrow, which is facilitated by a contractile ring made up of actin filaments. This process physically constricts the cell membrane until the two daughter cells are completely separated. In contrast, plant cells undergo cytokinesis by forming a cell plate; vesicles carrying cell wall materials gather at the center of the dividing cell and fuse to create a new membrane that develops into a new cell wall. This difference is largely due to the rigid structure of plant cell walls that necessitates a different approach to division.
• Evaluate the significance of proper cytokinesis in maintaining genetic stability within a population of dividing cells.
  • Proper cytokinesis is essential for maintaining genetic stability because it ensures that each daughter cell receives an accurate and complete set of organelles and genetic material. Disruptions in cytokinesis can lead to errors such as aneuploidy, where daughter cells have an abnormal number of chromosomes, which can have significant consequences like cancer or developmental disorders. Thus, successful cytokinesis directly impacts not only individual cell health but also influences the overall genetic integrity within tissues and across generations.

Related terms

Cleavage Furrow: A shallow groove that forms in the cell membrane during cytokinesis in animal cells, helping to physically separate the two daughter cells.

Cell Plate: A structure that forms during cytokinesis in plant cells, consisting of vesicles that coalesce at the center of the dividing cell to create a new cell wall.

Mitosis: The process of nuclear division in eukaryotic cells that precedes cytokinesis, resulting in two identical nuclei.