In animal cells, how do daughter cells physically split apart after mitosis during cytokinesis?

• A. Chromosomes are pulled to opposite poles by shortening of kinetochore microtubules, which directly divides the cytoplasm
• B. New nuclei form and then the nuclear envelope expands outward until it separates the cell into two compartments
• C. A contractile ring of actin and myosin II constricts at the cell equator to form a cleavage furrow that pinches the cell into two
• D. A cell plate forms from Golgi-derived vesicles fusing at the center of the cell, creating a new wall that splits the cell

Answer: (C)

Verified step by step guidance

1. Understand that cytokinesis is the process following mitosis where the cytoplasm divides to form two separate daughter cells.
2. Recognize that in animal cells, this physical separation is achieved by a contractile ring composed of actin filaments and myosin II motor proteins.
3. Know that this contractile ring assembles at the cell equator, the midpoint between the two sets of separated chromosomes.
4. The contractile ring constricts, much like a drawstring, creating an indentation called the cleavage furrow.
5. This cleavage furrow deepens until the cell membrane is pinched completely, resulting in two distinct daughter cells.