Identifying a breeding approach — selecting a naturally occurring variant with desirable traits and crossing it repeatedly is an example of:
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ATraditional plant breeding (selection and crossing)
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BTransgenic (recombinant DNA) technology
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CMutant selection induced by chemical or physical mutagens
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DNone of these
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EGenome editing with site-directed nucleases
Answer
Correct Answer: Traditional plant breeding (selection and crossing)
Explanation
Introduction / Context:Crop improvement can occur by conventional breeding or by direct genetic manipulation. Recognizing which process matches a described scenario is fundamental in agricultural biotechnology education.
Given Data / Assumptions:
- A naturally occurring variant is identified in a population.
- This variant is selectively bred (crossed/selected) to fix the trait.
- No direct gene transfer or targeted mutagenesis is stated.
Concept / Approach:
Traditional plant breeding relies on phenotypic selection and hybridization among existing germplasm. Transgenic methods introduce DNA across species or constructs; mutant selection typically follows induced mutagenesis; genome editing applies precise nucleases. None of these are implied in the scenario.
Step-by-Step Solution:
Match the description to breeding strategies.Note absence of recombinant DNA, mutagens, or gene editing.Identify selective crossing as classical breeding.Choose “Traditional plant breeding.”Verification / Alternative check:
Plant breeding textbooks define mass selection and pedigree selection of natural variants as conventional breeding.
Why Other Options Are Wrong:
Transgenic tech and genome editing involve direct DNA manipulation; mutant selection typically follows induced mutagenesis, which is not stated.
Common Pitfalls:
Assuming any “improved plant” is transgenic; conventional breeding has produced most of the world’s crop varieties historically.
Final Answer:
Traditional plant breeding (selection and crossing)