Cytokinesis

Definition

Cytokinesis is the process during cell division in which the cytoplasm of a parental cell is divided into two daughter cells. This process typically follows the end of mitosis or meiosis, ensuring that each daughter cell receives an adequate share of the cytoplasmic components and organelles necessary for survival and function. Cytokinesis is a crucial step in the cell cycle that marks the final phase of cell division, leading to two distinct, genetically identical cells.

5 Must Know Facts For Your Next Test

1. Cytokinesis can vary between plant and animal cells; in animal cells, it involves the formation of a cleavage furrow, while in plant cells, a cell plate forms to separate the two daughter cells.
2. During cytokinesis, the cytoskeleton plays an essential role by helping to constrict the cell membrane and ensuring proper distribution of organelles between the daughter cells.
3. Cytokinesis is tightly regulated and must occur after mitosis to ensure that each daughter cell has equal access to cellular materials and genetic information.
4. Errors during cytokinesis can lead to unequal distribution of cytoplasm and organelles, potentially resulting in cell dysfunction or diseases such as cancer.
5. In some cases, such as in certain fungi and algae, cytokinesis may not occur after nuclear division, leading to multinucleated cells.

Review Questions

• How does cytokinesis differ between plant and animal cells, and what are the implications of these differences?
  • Cytokinesis differs significantly between plant and animal cells mainly in its mechanism. In animal cells, a cleavage furrow forms due to the contraction of actin filaments in the cytoskeleton, pinching the cell into two. In contrast, plant cells form a cell plate due to vesicles carrying cell wall materials that fuse at the center of the dividing cell. These differences are crucial as they reflect how each type of cell must maintain structural integrity and function during division.
• Discuss the role of the cytoskeleton in cytokinesis and how it contributes to successful cell division.
  • The cytoskeleton plays a vital role in cytokinesis by providing structural support and facilitating movement. Actin filaments interact with myosin to create tension and contractile forces that form the cleavage furrow in animal cells. Additionally, microtubules help position and transport vesicles containing necessary materials for constructing the new cell membrane and wall. This orchestration ensures that both daughter cells receive an appropriate share of cellular components and maintain their integrity after division.
• Evaluate the consequences of errors occurring during cytokinesis and their potential impact on cellular health.
  • Errors during cytokinesis can have significant consequences for cellular health. If cytokinesis is incomplete or unequal, it can lead to daughter cells with abnormal numbers of organelles or genetic material. This can disrupt cellular function and may contribute to diseases such as cancer, where uncontrolled cell division occurs. Furthermore, multinucleated cells may arise from failed cytokinesis, impacting tissue development and regeneration processes. Understanding these implications highlights the importance of precise regulation during this critical phase of the cell cycle.

Related terms

Mitosis: The process of nuclear division in eukaryotic cells, resulting in two nuclei that are genetically identical to the original nucleus.

Cell Cycle: The series of phases that a cell goes through from one division to the next, including growth, DNA replication, mitosis, and cytokinesis.

Cleavage Furrow: A constriction that forms in the cell membrane during cytokinesis in animal cells, leading to the separation of the two daughter cells.