• Designer Crops: Crop varieties engineered or bred to exhibit tailor-made combinations of specific monogenic, oligogenic, or polygenic traits meeting exact industrial, nutritional, or processing criteria (e.g., specific fatty acid profiles, modified starch amylose ratios, or stacked abiotic/biotic stress resistance cassettes). (Correct answer: Option 3)

• Statement (I) is Incorrect: In maize (Zea mays), Stock 6 is a classical maternal (gynogenetic) haploid inducer line developed by Coe (1959); when used as a male pollinator on diploid females, it induces maternal haploid progeny at a frequency of approximately $2-3\%$, not paternal haploidy.
• Statement (II) is Incorrect: Paternal haploid induction (androgenesis) in maize is mediated by the _indeterminate gametophyte_ (_ig1_) mutation (discovered by Kermicle, 1969), which affects female embryo sac development; Stock 6 gynogenesis is governed by mutations in the pollen-specific phospholipase gene qhir1 / MTL / NLD / ZmPLA1, not the ig1 gene.
• Conclusion: Both Statement (I) and Statement (II) are incorrect (Option 2).

Correct option: (2) Both Statement (I) and Statement (Il) are incorrect

• Allelic Fixation in Doubled Haploids:
• Doubled haploid (DH) lines are produced via chromosome doubling of haploid cells, achieving immediate and total homozygosity ($F = 1.0$) across all loci in a single generation.
• At any single biallelic locus ($A/a$), a DH line is completely fixed: gene frequency is either $p = 1.0$ (homozygous $AA$) or $p = 0.0$ (homozygous $aa$).
• When comparing any two DH inbred lines:
• If both carry the same allele: $y = |1 - 1| = 0$ (or $|0 - 0| = 0$).
• If they carry alternate alleles: $y = |1 - 0| = 1$.
• Conclusion: The difference in gene frequency $y$ can only be 0 or 1. (Correct answer: Option 3)