Question

Colchicine brings about
A. Polyploidy
B. Cell division
C. Cell elongation
D. cell differentiation

Answer 1

Hint:Colchicine is also used to produce fertile hybrids between species with different chromosome numbers. It is used by plant breeders to grow plants with the desired characteristics.

Complete Answer:
Colchicine is an alkaloid drug isolated from the corm of the autumn crocus (Colchicum autumnale). It prevents mitosis in the metaphase by inhibiting the development of spindle fibrils, slowing the division of the centromeres and preventing the division of the centrioles. Cells begin mitosis, but chromosomes cannot be separated. If colchicine is given to an animal or applied to a cell culture, all cells starting with mitosis after treatment will be stopped at the metaphase level.

Polyploidy is a condition where cells possess more than two sets of chromosomes which also serve as an important mechanism for plant evolution. Polyploidy may arise spontaneously due to the development of unreduced gametes or may be chemically caused by doubling the number of chromosomes in somatic cells. Natural polyploid plants are typically scarce, so polyploidy is caused synthetically by mitotic inhibitors. Colchicine is a mitotic inhibitor commonly used to cause polyploidy in plants during their cell division by preventing chromosome separation.

Thus, the correct answer is A i.e., Polyploidy.

Note:Polyploid plants are created in an attempt to develop new plants with new characteristics. The end result is a cell that already has twice as many genes as it would usually have. If this cell divides again in the future, the doubled number of chromosomes will be transmitted to the offspring cells.