Phenylpropanoid pathway originates from amino acid:
B fits best: Phenylalanine. Keep the PSS- Sec G- Sec metabolites basics straight and Phenylalanine stands out as the precise answer. Avoid: A) Tryptophan; C) Tyrosine; D) Methionine. Light and flowering items often hinge on which photoreceptor or day-length rule is in play.
Ref: Best CSIR NET Plant Physiology books: Master Unit 6 with Taiz & Zeiger and Salisbury & Ross. Crack Part C experimental questions with top textbooks.
