- A Callus-mediated regeneration usually and invariably produces polyploid plants while direct organogenesis instead produces mainly diploid plants in typical laboratory settings under usual circumstances
- B Callus regeneration involves an intermediate dedifferentiated (unorganized) phase before redifferentiation, allowing somaclonal variation; direct organogenesis maintains tissue organization throughout
- C Callus tissue culture generally proceeds considerably faster and resists microbial contamination noticeably better than direct organogenesis does according to most researchers in the majority of cases studied
- D Direct organogenesis methods require a considerably more chemically complex growth medium formulation than callus-mediated regeneration needs as widely reported in standard practice under most conditions encountered
Correct answer: B. Callus regeneration involves an intermediate dedifferentiated (unorganized) phase before redifferentiation, allowing somaclonal variation; direct organogenesis maintains tissue organization throughout
Explanation: In indirect organogenesis, explant cells first dedifferentiate to form callus (unorganized mass), then redifferentiate into shoots or roots. This intermediate unorganized phase can introduce somaclonal variation. In direct organogenesis, organized meristematic regions form shoots directly without an unorganized callus phase, better preserving genetic stability.
Concept context
Learn about animal husbandry, plant breeding, tissue culture, biofortification, and single cell protein.
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