Developmental biology concept — “Cellular totipotency” is best described as a property most broadly exhibited by which kingdom in practical biotechnology?
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APlants (most somatic cells can regenerate a whole plant under the right conditions)
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BAnimals (most somatic cells routinely regenerate whole organisms)
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CBacteria (individual cells regenerate multicellular organisms)
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DAll of these equally
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EFungi (filamentous forms readily regenerate whole plants)
Answer
Correct Answer: Plants (most somatic cells can regenerate a whole plant under the right conditions)
Explanation
Introduction / Context:Totipotency refers to the inherent potential of a single cell to regenerate into a complete organism. In practical tissue culture, plant somatic cells frequently display totipotency, enabling mass propagation, rescue of hybrids, and regeneration after genetic transformation.
Given Data / Assumptions:
- Plant cells can dedifferentiate and re-enter the cell cycle.
- Hormone regimes (auxin/cytokinin) guide differentiation into shoots and roots.
- Animal somatic cells are generally not totipotent (exceptions: very early embryonic cells).
Concept / Approach:While the zygote of many organisms is totipotent by definition, the question targets practical, widely used totipotency in biotechnology. Plants uniquely and routinely express totipotency across diverse somatic tissues.
Step-by-Step Solution:
Identify the domain with routine whole-organism regeneration from somatic cells.Associate this with plant tissue culture successes across species.Select plants as the correct answer.Verification / Alternative check:Protocols for callus induction, organogenesis, and somatic embryogenesis in many crops (e.g., rice, tobacco) are standard and demonstrate totipotency.
Why Other Options Are Wrong:
b) Animal somatic cells are typically pluripotent at best when reprogrammed, not naturally totipotent.c) Single bacteria form colonies but not multicellular plants/animals.d,e) Incorrect generalizations.Common Pitfalls:Confusing pluripotency/induced pluripotency with totipotency; only totipotency yields a full organism including extra-embryonic tissues in animals.
Final Answer:Plants (most somatic cells can regenerate a whole plant under the right conditions).