Teaching MPPSC Assistant Professor Mock Test Series 2025 Life Sciences System Physiology Plant Plant hormones
Which statement accurately describes an aspect of the brassinosteroid (BR) biosynthesis pathway in plants?
1
Brassinosteroids are synthesized directly from glucose, utilizing a series of reactions primarily facilitated by glycosyltransferase enzymes to produce the active hormone.
2
The biosynthesis of brassinosteroids is initiated from the plant sterol Campesterol, and involves critical reactions catalyzed by the cytochrome P450 monooxygenase (CYP) enzyme family associated with the endoplasmic reticulum (ER).
3
Brassinosteroid biosynthesis exclusively involves the addition of methyl groups to cholesterol, a process that does not require cytochrome P450 monooxygenase (CYP) enzymes or other ER-associated proteins.
4
Active brassinosteroid levels in plants are strictly regulated through synthesis from Campesterol without involving any inactivation or catabolic reactions, ensuring constant levels of brassinosteroids under all physiological conditions