Tissue culture can be used to produce a whole potato plant from genetically identical cells. This demonstrates what about plant cells?

• A. All plant cells have the exact same gene expression.
• B. A single cell can give rise to a whole plant.
• C. Plants cannot regenerate from tissue culture.
• D. DNA changes during tissue culture.

Answer: (B)

Plant cells are totipotent, meaning a single cell has the potential to develop into all the needed cell types to form a complete organism. In tissue culture, a potato cell or small tissue piece can be coaxed with hormones and nutrients to revert to an undifferentiated state and then re-differentiate into shoots and roots, ultimately producing a whole plant. This shows that the same genetic material can generate an entire organism when given the right signals, not that the DNA changes during culture. It also reflects why plants can regenerate from what starts as a small piece of tissue, rather than implying that all plant cells express exactly the same genes at all times.