RRB Group D 1 Dec 2025 Shift 1 Solved Paper

Concept:Short height is recessive, so the genotype must be $tt$.Round seeds are dominant, so the genotype can be $RR$ or $Rr$.We need the combination that gives both short height and round seeds.Explanation:For the plant to be short, it must carry two recessive alleles: $tt$.For round seeds, at least one dominant $R$ allele is needed: $RR$ or $Rr$.Option B ($ttRR$) has $tt$ for short height and $RR$ for round seeds.Options A, C, and D all include a $T$ allele, which would make the plant tall.So only $ttRR$ meets the requirement of short height and round seeds.Answer:$ttRR$ (Option B)