A Totipotent cell means A. An undifferentiated cell capable of developing into a system or entire plant. B. A differentiated cell capable of developing into an organ. C. An undifferentiated cell capable of developing into a complete embryo. D. Cell which lacks the capability to differentiate into an organ or system.
Hint: Stem cells are characterised by their degree of viability, which relates to their differing ability to differentiate into various types of cells and developing into a new system.
Complete Answer: A totipotent cell is a single cell, which provides proper maternal support, and can give rise to a new organism. Tarkowski (1959)2 conducted the original totipotency test in mice, which isolated a single blastomere (cells produced by divisions of the zygote, consisting of 2–16 cells) and placed it in an empty zone pellucid, and tracked its development into live-born youth. A totipotent cell refers to an undifferentiated cell which can grow into a system or a whole plant. The totipotent cells have enormous cytoplasm and an active nucleus that allows for the rapid division. For example, the growth hormones are handled with a callus to enable cell division and differentiation. When treated with auxin, the callus promotes rooting and when treated with cytokine it stimulates cell maturation, differentiation and ultimately promotes stem growth. It differentiates into the different vegetative plant after stem formation.
So the correct answer is the option ‘A’ “An undifferentiated cell capable of developing into a system or entire plant.”
Note: - Totipotent cells can form all types of cells in a body, including the cells that are extraembryonic, or placental. - The only totipotent cells are the embryonic cells inside the first couple of cell divisions after fertilisation. - Pluripotent cells can generate any of the cell types that make up the body; pluripotent are called embryonic stem cells. - Multipotent cells can grow into more than one type of cell, but are more constrained than pluripotent cells; multipotency is called adult stem cells and cord blood stem cells.