Advanced Placement (AP) Biology Practice Exam

What is cytokinesis?

1. The synthesis of DNA during interphase

2. The division of the cytoplasm to form two daughter cells

3. The separation of sister chromatids

4. The combination of genetic material

The correct answer is: The division of the cytoplasm to form two daughter cells

Cytokinesis is specifically defined as the process in which the cytoplasm of a parental cell is divided into two daughter cells, following mitosis or meiosis. This is a key stage in cell division, ensuring that each daughter cell receives not only a complete set of chromosomes but also the necessary components and organelles to function independently. During cytokinesis in animal cells, a contractile ring forms and pinches the cell membrane inwards, creating two separate cells. In contrast, plant cells form a cell plate that develops into a new cell wall between the daughter cells. This division of the cytoplasm is crucial for the proper distribution of cellular materials and for maintaining cellular functions post-division. The other options refer to different processes in the cell cycle, such as DNA synthesis during interphase, the separation of sister chromatids during anaphase, and the combination of genetic material which describes processes such as fertilization or genetic recombination. None of these directly pertain to the definition or process of cytokinesis as it specifically relates to cytoplasmic division.