AP BIOLOGY

Detailed explanation-1: -If cells in the process of dividing are subjected to colchicine, a drug that interferes with the functioning of the spindle apparatus, at which stage will mitosis be arrested? The answer is at the metaphase stage of mitosis when the spindle apparatus has failed to properly position chromosomes.

Detailed explanation-2: -Colchicine is an alkaloid obtained from the plant Colchicum autumnale. During mitosis it does not interfere with the replication of chromosome but prevents the formation of spindle fibres. During metaphase it inhibits the assemblage of microtubules hence spindle formation does not occur.

Detailed explanation-3: -Answer and Explanation: Colchicine is a drug that interferes with mitotic cell division during the cell cycle. Colchicine hinders the production of spindle fibers, and hence metaphase does not progress, and the cell cycle stops at this stage.

Detailed explanation-4: -Since colchicines inhibits growth of spindle fibres and the major role of spindle fibre is to pull the chromosomes to the poles during anaphase. So, colchicines treated cells will enter in cell cycle but will be arrested at metaphase.

Detailed explanation-5: -Solution : Colchicine is obtained form cochicum autumnale plant, which inhibits the formation of spindle fibers in metaphase.