Seed Quality Control

• Bipartite Nature of Gene Regulatory Networks (GRN): GRNs are mathematically modeled as bipartite directed graphs comprising two distinct classes of nodes: regulatory elements (such as transcription factors, small RNAs, and signaling proteins) and target gene loci whose expression is modulated.
• Directionality of Information Flow: Edges connecting nodes possess intrinsic directionality ($A

ightarrow B$), signifying asymmetric regulatory control wherein upstream transcription factors bind specific promoter or enhancer cis-elements to regulate downstream target genes, rather than the reverse.

• Assertion and Reason Verification: Assertion (A) accurately defines GRNs as bipartite and directional networks, and Reason (R) provides the precise mechanistic and topological explanation for why this structural bipartiteness and directionality arise.
• Conclusion: Both (A) and (R) are true and (R) is the correct explanation of (A) (Option 1).

Correct option: (1) Both (A) and (R) are true and (R) is the correct explanation of (A)

• Inhibitory Gene Interaction (13:3 Ratio):
• Occurs when a dominant allele at one locus ($I$) suppresses the phenotypic expression of a dominant allele at a second locus ($R$).
• Genotypes: $I\_ \ R\_$ (Resistant), $I\_ \ rr$ (Resistant), $ii\ rr$ (Resistant) $\rightarrow 13/16$ Resistant; $ii\ R\_ \rightarrow 3/16$ Susceptible.
• Test Cross Segregation ($AaBb \times aabb$):
• $1\ AaBb$ (Inhibited $\rightarrow$ Resistant)
• $1\ Aabb$ (Resistant)
• $1\ aabb$ (Resistant)
• $1\ aaBb$ (Uninhibited dominant $\rightarrow$ Susceptible)
• Conclusion: Segregates in a test cross ratio of 3 resistant and 1 susceptible. (Correct answer: Option 1)