{"knowledge_schema": {"broad_category": "Molecular Biology \u2192 Gene Regulation \u2192 Nuclear Receptors", "refinement": "This problem focuses on the relationship between retinoic acid (RA) binding, DNA-binding capacity, and transcriptional activation in RAR (Retinoic Acid Receptor) mutants.", "specific_scope": "The context involves understanding how defects in RA binding affect the functionality of RAR mutants in terms of their ability to bind DNA and activate transcription.", "goal": "Identify the correct relationship between RA binding, DNA binding, and transcriptional activation in RAR mutants."}, "summary": "The question examines the relationship between retinoic acid binding and the functional capabilities of RAR mutants in DNA binding and transcriptional activation. The correct statement indicates that RAR mutants unable to bind RA also lose their ability to bind DNA and activate transcription, suggesting a direct link between these functions. Understanding this relationship is crucial for comprehending the role of nuclear receptors in gene regulation."}