Question

Colchicine results in doubling of chromosome number due to

• A. Non-formation of spindle
• B. Non-pairing of chromosomes
• C. Double replication of chromosomes
• D. Splitting of chromosomes

Answer 1

The correct option is A Non-formation of spindle

Colchicine is a toxic chemical that is often used to induce polyploidy in plants. Basically, the colchicine prevents the microtubule formation during cell division, thus the chromosomes do not pull apart like they normally do. The end result is a cell that now has double the number of chromosomes that it would normally have. If this cell divides again in the future, then doubled number of chromosomes are passed to the offspring cells. Plants that having more than normal two sets of chromosomes are termed “polyploidy”. In general, although specific names are given to the certain chromosome numbers. The use of colchicine to generate a diploid from a monoploid. Colchicine added to mitotic cells during metaphase and anaphase disrupts spindle fiber formation, preventing the migration of chromatids after the centromere is split.

Therefore, the correct answer is option A.