Cleavage furrow

Definition

A cleavage furrow is a specialized indentation that forms in the cell membrane during cytokinesis, the final stage of cell division. This structure is crucial for physically separating the daughter cells as it contracts and pinches the cell into two distinct entities, ensuring that each new cell receives an appropriate amount of cytoplasm and organelles. The formation of the cleavage furrow is essential for maintaining proper cellular function and genetic stability in the resulting cells.

5 Must Know Facts For Your Next Test

1. The cleavage furrow is formed by the contractile ring, which consists of actin filaments and myosin motor proteins that facilitate the pinching process.
2. In animal cells, the cleavage furrow begins to form as the mitotic spindle pulls apart the chromosomes, signaling the start of cytokinesis.
3. The cleavage furrow deepens until it eventually divides the cell into two separate daughter cells, each with its own nucleus and cytoplasmic content.
4. Plant cells do not form a cleavage furrow; instead, they build a cell plate at the center of the cell to separate the daughter cells due to their rigid cell walls.
5. Proper formation and function of the cleavage furrow are critical, as errors can lead to unequal distribution of organelles and genetic material, potentially causing cell dysfunction or disease.

Review Questions

• How does the cleavage furrow contribute to the process of cytokinesis in animal cells?
  • The cleavage furrow plays a pivotal role in cytokinesis by serving as the physical means through which animal cells divide. It forms as a result of the contractile ring beneath the cell membrane contracting, leading to an indentation that deepens until it separates the cell into two. This ensures that each daughter cell receives an appropriate share of cytoplasm and organelles, maintaining their viability and function post-division.
• Compare and contrast the mechanisms of cytokinesis in animal cells and plant cells, focusing on the role of cleavage furrow and other structures involved.
  • In animal cells, cytokinesis is characterized by the formation of a cleavage furrow, which is initiated by a contractile ring made up of actin and myosin. This pinches the cell into two distinct daughter cells. In contrast, plant cells do not form a cleavage furrow due to their rigid cell walls; instead, they create a cell plate from vesicles that merge at the center of the dividing cell. This difference highlights how structural variations between animal and plant cells dictate their respective methods of completing cell division.
• Evaluate the importance of proper cleavage furrow formation during cytokinesis and its implications for cellular health and genetic stability.
  • Proper formation of the cleavage furrow during cytokinesis is vital for ensuring that each daughter cell inherits an appropriate amount of cytoplasm, organelles, and genetic material. Any errors in this process can lead to uneven distribution, which may result in cellular dysfunction or contribute to diseases such as cancer. Thus, understanding and regulating this process is crucial for maintaining cellular health and genetic stability across generations of cells.

Related terms

cytokinesis:

The process that follows mitosis or meiosis, where the cytoplasm of a parental cell is divided into two daughter cells.

contractile ring:

A structure composed of actin and myosin filaments that forms beneath the plasma membrane during cytokinesis and aids in the formation of the cleavage furrow.

mitosis:

The process of nuclear division that leads to the formation of two genetically identical daughter nuclei, typically followed by cytokinesis.