The drug cytochalasin B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by cytochalasin B? a. spindle formation b. spindle attachment to kinetochores c. cell elongation during anaphase d. cleavage furrow formation and cytokinesis

Verified step by step guidance

1. Understand the role of actin in the cell: Actin is a crucial component of the cytoskeleton of eukaryotic cells, involved in various cellular processes including muscle contraction, cell motility, and structural support.
2. Identify the process involving actin during the cell cycle: During the cell cycle, actin is particularly important in the process of cytokinesis, where it helps in the formation of the cleavage furrow that divides the cell into two daughter cells.
3. Analyze the options in relation to actin's function: Since cytochalasin B blocks the function of actin, we need to determine which of the listed options is directly related to actin's role in the cell cycle.
4. Link the disruption caused by cytochalasin B to the correct option: Blocking actin's function would directly impair the formation of the cleavage furrow, a critical step in cytokinesis, where the cell physically divides.
5. Conclude the most affected aspect of the cell cycle by cytochalasin B: Therefore, the aspect of the animal cell cycle most disrupted by cytochalasin B would be 'd. cleavage furrow formation and cytokinesis'.

Key Concepts

Actin and its Role in Cell Division

Actin is a crucial component of the cytoskeleton in eukaryotic cells, playing a vital role in various cellular processes, including cell shape, motility, and division. During cell division, actin filaments contribute to the formation of the contractile ring that leads to cytokinesis, the final separation of the daughter cells.

Cytokinesis

Cytokinesis is the process that follows mitosis, where the cytoplasm of a parental cell is divided into two daughter cells. This process is characterized by the formation of a cleavage furrow, which is driven by the contraction of actin and myosin filaments. Disruption of actin function, such as by cytochalasin B, can severely impair this process.

Cell Cycle Phases

The cell cycle consists of several phases: interphase (G1, S, G2) and mitotic phase (M), which includes mitosis and cytokinesis. Each phase is tightly regulated to ensure proper cell division. Understanding these phases is essential to identify how disruptions, like those caused by cytochalasin B, can affect specific processes such as cytokinesis.