Question 37

Animal cells divide during cytokinesis through a contractile ring.

Cytokinesis in animal cells occurs via the formation of a contractile ring, which pinches the cell membrane inwards, leading to the separation of the daughter cells.

A) Contractile ring

This option is correct because animal cells utilize a contractile ring made of actin and myosin filaments. During cytokinesis, this ring constricts, pulling the membrane inward and resulting in the physical division of the cell into two distinct daughter cells.

B) Cell plate

This option is incorrect for animal cells, as the cell plate formation is characteristic of plant cells during cytokinesis. In plant cells, vesicles fuse at the center of the cell to form a cell plate, which eventually develops into the cell wall separating the two daughter cells.

C) Both

This option is incorrect because it suggests that both mechanisms are utilized by animal cells during cytokinesis. However, animal cells rely solely on the contractile ring, while plant cells use the cell plate, making this choice misleading.

D) None of the above

This option is incorrect as it denies any mechanism for animal cell division during cytokinesis. The existence of the contractile ring clearly demonstrates that animal cells do have a defined process for cytokinesis.

Conclusion

The correct answer is A) Contractile ring, as it accurately describes the mechanism used by animal cells during cytokinesis. Options B, C, and D either misrepresent the processes involved or incorrectly assert that animal cells do not utilize a specific method for cell division. The contractile ring is essential for successful cytokinesis in animal cells, thereby clarifying the distinction in cellular processes between animal and plant cells.