Cytokinesis

Definition

Cytokinesis is the process during cell division where the cytoplasm of a parental cell divides into two daughter cells. This crucial step occurs after mitosis or meiosis, ensuring that each new cell receives the necessary organelles and cytoplasmic components to function effectively. Cytokinesis plays a vital role in growth, tissue repair, and reproduction in organisms by facilitating the separation of cellular material.

5 Must Know Facts For Your Next Test

1. Cytokinesis can occur differently in 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, various proteins and structures, such as actin filaments and myosin, play critical roles in the physical division of the cytoplasm.
3. The timing of cytokinesis is tightly regulated to ensure it follows mitosis or meiosis appropriately, preventing issues such as aneuploidy.
4. Failure of cytokinesis can lead to multinucleated cells or abnormal cell growth, which is often associated with cancer.
5. Cytokinesis is essential for maintaining proper cell size and function, as each daughter cell must inherit enough cellular material to survive and thrive.

Review Questions

• Explain how cytokinesis differs between plant and animal cells, highlighting the structures involved.
  • Cytokinesis differs significantly between plant and animal cells due to their distinct structures. In animal cells, cytokinesis is achieved through the formation of a cleavage furrow that pinches the cell membrane inward, ultimately splitting the cell into two daughter cells. In contrast, plant cells cannot pinch due to their rigid cell walls; instead, they form a cell plate at the center of the dividing cell, which eventually develops into a new cell wall separating the two daughter cells.
• Discuss the importance of regulatory mechanisms in ensuring that cytokinesis occurs at the correct time during cell division.
  • Regulatory mechanisms are crucial for ensuring that cytokinesis occurs at the appropriate time during cell division. These mechanisms include checkpoints that assess whether mitosis has been completed correctly before cytokinesis begins. If errors occur during mitosis or if there are issues with chromosome alignment, these regulatory processes can delay or prevent cytokinesis, thereby protecting against aneuploidy and ensuring that each daughter cell receives a complete set of genetic material.
• Evaluate the consequences of failed cytokinesis on cellular health and development, particularly in relation to cancer progression.
  • Failed cytokinesis can lead to significant consequences for cellular health and development, most notably resulting in multinucleated cells or abnormal cell division. This irregularity can disrupt normal cellular function and contribute to tumorigenesis by allowing cells to bypass normal growth controls. As a result, when cytokinesis fails repeatedly within tissues, it can promote cancer progression by enabling uncontrolled proliferation and genetic instability within affected cells.

Related terms

Mitosis: The phase of cell division in which the nucleus divides, resulting in the formation of two genetically identical nuclei.

Meiosis: A specialized form of cell division that reduces the chromosome number by half, producing gametes (sperm and eggs) for sexual reproduction.

Cell Cycle: The series of phases that a cell goes through as it grows and divides, including interphase and the mitotic phase.