CELL DIVISION
THE CELL CYCLE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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microtubule organization of spindle fibers
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DNA synthesis of spindle protein
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membrane transport of spindle fibers
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RNA synthesis of spindle protein
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Detailed explanation-1: -The alkaloid drug, colchicine, extracted from the corm of the autumn crocus (Colchicum autumnale), arrests mitosis in metaphase by interfering with the formation of spindle fibrils, thereby retarding the division of the centromeres and preventing division of the centrioles.
Detailed explanation-2: -At a cellular level, colchicine is an antimitotic agent that inhibits mitosis by preventing the polymerization of tubulin, 11, 12 a constituent microtubule protein, thereby disturbing those processes dependent on microtubule function such as cell motility, intracellular movement, cell polarity, and mitosis.
Detailed explanation-3: -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-4: -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.