Colchicine is a chemical that when applied to a cell during mitosis can be used to "freeze" cells in metaphase by preventing the chromosomes from moving away from the metaphase plate. What part of the cell does colchicine most likely affect?

a. chromosome structure

b. spindle fibers

c. nuclear membrane

d. cell membrane

The correct answer is - spindle fibers.

Explanation:

The colchicine is the chemical that obtains from the plant which is used to treat gout and joint swellings. Colchicine freezes the cell metaphase stage by inhibiting microtubule polymerization.

This inhibits the function of the tubulin enzyme that prevents the assembly of the mitotic spindle fibers which separates the chromosomes to opposite poles from the metaphase plate.

Thus, the correct answer is - spindle fibers.