Question

Chromosomes in metaphase get arranged at the equatorial plate (see Fig. 1). When these cells are treated with colchicine, cell division is arrested and the cells never enter anaphase. If we were to compare a colchicine treated cell at metaphase and an untreated cell in the same phase, we notice that chromosomes are more dispersed and do not arrange themselves on the equatorial plate in the treated cells (see Fig 2.).
Using this information, which of the following will be affected by colchicine?

• A. Centromere
• B. Spindle fiber
• C. Centriole
• D. Arms of chromosomes

Answer 1

The correct option is B Spindle fiber

A spindle poison is a poison that interrupts the cell division by affecting the spindles.axol. Colchicine is an alkaloid which inhibits the microtubule polymerization, organization, and orientation of spindle fibers which is essential to mitosis. Since there is no formation of spindle fibres, there will be no arrangement of the chromosomes.

Thus, the correct answer is option B.