What is the correct sequence of stages during the cleavage period in early embryonic development?

• A. Zygote, Morula, Blastula
• B. Blastula, Morula, Zygote
• C. Morula, Zygote, Blastula
• D. Zygote, Blastula, Morula

Answer: (A)

Verified step by step guidance

1. Understand that cleavage is a series of rapid mitotic divisions of the zygote that leads to the formation of a multicellular structure.
2. Identify the initial stage: The process begins with the zygote, which is the fertilized egg cell.
3. Recognize the next stage: The zygote undergoes several rounds of cell division to form a solid ball of cells known as the morula.
4. Identify the final stage: The morula continues to divide and forms a hollow structure called the blastula.
5. Sequence the stages: The correct sequence of stages during the cleavage period is Zygote, Morula, Blastula.