Certificate In Psychology (CPSY) Practice Exam

During prenatal cell cleavage, which statement is true?

1. chromosomes migrate into adjacent cells.

2. zygotes migrate into adjacent cells.

3. cells all divide simultaneously.

4. cells do not all divide at the same time.

The correct answer is: cells do not all divide at the same time.

During prenatal cell cleavage, the process involves the division of the zygote into smaller cells called blastomeres. It is crucial to understand that these divisions do not occur all at once. Instead, they happen in a carefully coordinated manner, where the timing of each cell division might vary. This results in a series of rapid divisions that lead to the formation of a multicellular structure from the initial single-cell zygote. The notion that cells do not all divide at the same time reflects the biological reality of cleavage-stage embryonic development. Some cells may be at different stages of division due to the influence of cellular signals and the physical environment they are in. This asynchronous division is essential for the proper formation and organization of tissues and structures as development progresses. The other statements imply a misunderstanding of the cleavage process. Chromosomes do not migrate into adjacent cells, as cleavage focuses on dividing the existing zygote. Likewise, zygotes themselves do not migrate; rather, they undergo cleavage. The idea that all cells divide simultaneously contradicts the fundamental nature of cleavage dynamics, emphasizing why the fourth statement is the accurate representation of the cleavage stage in early embryonic development.