Veterinary Technician Practice Exam

What is the stage of cell division known for the formation of the spindle at the center of the cell?

1. Telophase

2. Metaphase

3. Prophase

4. Interphase

The correct answer is: Metaphase

The stage of cell division characterized by the formation of the spindle at the center of the cell is metaphase. During this phase, the chromosomes align at the metaphase plate, which is an imaginary plane equidistant from the two spindle poles. The spindle fibers attach to the centromeres of the chromosomes, ensuring that each daughter cell will receive an identical set of chromosomes when they are pulled apart in the next stage of division. Prophase, while preceding metaphase, is primarily marked by the condensation of chromatin into distinct chromosomes and the disintegration of the nuclear envelope. The spindle apparatus begins to form during prophase, but it is in metaphase that the spindle is fully developed and aligned properly for the chromosomes to be positioned correctly. Telophase occurs after metaphase and involves the separation of the chromosomes at the poles and the reformation of the nuclear envelopes around the two sets of chromosomes, but it does not involve spindle formation. Interphase is the phase during which the cell is not actively dividing and is usually divided into G1, S, and G2 phases. This phase is critical for cell growth and DNA replication, but it does not involve spindle formation. Thus, the defining characteristic of spindle formation at the cell center aligns uniquely with