Which of the following cells is considered totipotent in developmental biology?

• A. Neural stem cell
• B. Zygote
• C. Mesenchymal stem cell
• D. Hematopoietic stem cell

Answer: (B)

Verified step by step guidance

1. Understand the concept of totipotency: Totipotent cells have the ability to differentiate into all cell types, including both the embryonic and extra-embryonic tissues. This is a key characteristic in early developmental stages.
2. Identify the developmental stage of each cell type: Neural stem cells, mesenchymal stem cells, and hematopoietic stem cells are all specialized stem cells that can differentiate into specific types of cells but not all cell types.
3. Recognize the unique capability of a zygote: A zygote is the initial cell formed when a sperm cell fertilizes an egg cell. It is the earliest stage of development and has the potential to develop into a complete organism, making it totipotent.
4. Compare the differentiation potential: While neural, mesenchymal, and hematopoietic stem cells are multipotent (able to differentiate into multiple, but limited, cell types), the zygote is totipotent, capable of forming all cell types.
5. Conclude with the definition: Based on the definition of totipotency and the developmental potential of each cell type, the zygote is the only cell among the options that is considered totipotent.