Scombroid Fish Poisoning is due to the high levels of free ----------- in fish tissue
In general biology, core biological organization dictates that structure-function relationships govern cellular processes. Therefore Histidine is correct as it integrates fundamental principles, supported by mechanistic studies and conserved across related systems.
Ref: Campbell et al., Biology, 11th Edition, Chapter 2, Chemical Basis of Life, discusses fundamental biological principles and molecular organization providing broad foundation for life sciences understanding.
