Q.13 Which one of the following statements about polyploidy is correct?
(A) Autopolyploids are derived from a single species
(B) Autopolyploids are derived from two different species
(C) Allopolyploids are derived from a single species
(D) Allopolyploids are not fertile when mated with each other

Correct Answer: (A) Autopolyploids are derived from a single species

Autopolyploids form through genome duplication within one species, while allopolyploids arise from hybridization between different species.​

Option Analysis

Option (A) states autopolyploids derive from a single species. This holds true as they result from chromosome doubling in one species, like unreduced gametes fusing to create tetraploids.​

Option (B) claims autopolyploids come from two species. Incorrect, since that defines allopolyploids via interspecific hybridization.​

Option (C) says allopolyploids derive from one species. Wrong, as they combine genomes from multiple species, such as wheat from three diploid ancestors.​

Option (D) asserts allopolyploids lack fertility when mated. False, as fertile allopolyploids like bread wheat reproduce successfully due to stabilized chromosome pairing.​

Polyploidy represents a key mechanism in plant evolution where organisms possess more than two chromosome sets, driving speciation and crop improvement. Autopolyploids emerge from duplication within a single species, enhancing traits like size in potatoes. This CSIR NET-relevant concept contrasts with allopolyploids, formed by hybridizing distinct species.​

Key Differences

Evolutionary Significance

Autopolyploids boost vigor but face meiotic challenges, while allopolyploids gain hybrid vigor and novel traits, common in 15% of angiosperms. In agriculture, induced polyploidy creates seedless watermelons via autotriploids.​

CSIR NET Exam Tips

Focus on origins: autopolyploids = single species duplication; allopolyploids = interspecific hybrids. Practice with examples like Triticum aestivum (hexaploid allopolyploid).​