key term - Contractile Ring

Definition

The contractile ring is a dynamic structure that forms during cell division, specifically during cytokinesis, the process of splitting a parent cell into two daughter cells. It is composed of actin and myosin filaments that constrict, pulling the plasma membrane inward and dividing the cell into two distinct cells.

5 Must Know Facts For Your Next Test

1. The contractile ring assembles at the equatorial region of the dividing cell, just beneath the plasma membrane.
2. The constriction of the contractile ring is driven by the sliding of actin and myosin filaments, similar to the mechanism of muscle contraction.
3. The contractile ring is essential for the physical separation of the two daughter cells during cytokinesis.
4. Disruption of the contractile ring can lead to failed cell division and the formation of multinucleated cells.
5. The contractile ring is a highly dynamic structure, with actin and myosin constantly assembling and disassembling during the division process.

Review Questions

• Explain the role of the contractile ring in the process of cell division.
  • The contractile ring plays a crucial role in the final stage of cell division, known as cytokinesis. It is composed of actin and myosin filaments that constrict, pulling the plasma membrane inward and physically dividing the parent cell into two distinct daughter cells. The constriction of the contractile ring is driven by the sliding of actin and myosin filaments, similar to the mechanism of muscle contraction. This process is essential for the successful separation of the two daughter cells during cell division.
• Describe the assembly and dynamics of the contractile ring during cell division.
  • The contractile ring assembles at the equatorial region of the dividing cell, just beneath the plasma membrane. It is a highly dynamic structure, with actin and myosin constantly assembling and disassembling during the division process. The constriction of the contractile ring is driven by the sliding of actin and myosin filaments, similar to the mechanism of muscle contraction. This dynamic assembly and constriction of the contractile ring are crucial for the physical separation of the two daughter cells during cytokinesis.
• Analyze the consequences of a disruption in the contractile ring formation or function during cell division.
  • Disruption of the contractile ring can lead to failed cell division and the formation of multinucleated cells. The proper assembly and constriction of the contractile ring are essential for the successful physical separation of the two daughter cells during cytokinesis. If the contractile ring is disrupted, the cell division process may be impaired, resulting in the failure to fully separate the daughter cells. This can lead to the formation of multinucleated cells, which can have various implications for cellular function and tissue development.

Related terms

Cytokinesis:

The final stage of cell division, where the cytoplasm of a single cell is divided into two daughter cells.

Actin:

A globular protein that forms microfilaments, which are a major component of the cytoskeleton and the contractile ring.

Myosin:

A motor protein that interacts with actin filaments to generate the contractile force needed for the constriction of the contractile ring.