Which stem cell type is defined as having the ability to differentiate into all cell types, including extraembryonic tissues?

Which stem cell type is defined as having the ability to differentiate into all cell types, including extraembryonic tissues?

• A. Pluripotent
• B. Multipotent
• C. Unipotent
• D. Totipotent

Answer: (D)

Totipotent cells have the broadest developmental potential: they can form every cell type of the body plus the extraembryonic tissues that support development, such as the placenta. This means the earliest embryonic cells (like the zygote and the very early morula) can give rise to an entire organism and its supporting structures. As development progresses, cells become more restricted: pluripotent cells can form any body cell type but not placenta, while multipotent cells can form several related cell types within a lineage, and unipotent cells can form only one cell type. So, the ability to differentiate into all cell types including extraembryonic tissues points to totipotent.

Totipotent cells have the broadest developmental potential: they can form every cell type of the body plus the extraembryonic tissues that support development, such as the placenta. This means the earliest embryonic cells (like the zygote and the very early morula) can give rise to an entire organism and its supporting structures. As development progresses, cells become more restricted: pluripotent cells can form any body cell type but not placenta, while multipotent cells can form several related cell types within a lineage, and unipotent cells can form only one cell type. So, the ability to differentiate into all cell types including extraembryonic tissues points to totipotent.