TLS Online TPP Program

#Question id: 12519


Some given  statements about biosynthesis of Abscisic acid ;
a) ABA is synthesized in almost all cells that contain chloroplasts or amyloplasts
b) ABA is a 15-carbon terpenoid, or sesquiterpenoid, which is synthesized in plants by an indirect pathway via 40-carbon carotenoid intermediates
c) Cleavage of the carotenoid by the enzyme NCED (9-cis-epoxycarotenoid dioxygenase) is a rate-limiting
d) Oxidation by ABA-8′-hydroxylases lead to ABA inactivation, ABA can also be inactivated by conjugation, but this is irreversible. Both types of inactivation are also tightly regulated.
Which of the following  combination from the above statements  is correct?

#Unit 6. System Physiology – Plant
  1. B, C and D
  2. A, C and D
  3. A, B and C
  4. A and D only