Gibberellins: Plant Growth Promoters — NEET Biology
✅ Asked in NEET 2025Gibberellins are another kind of promotory PGR. There are more than 100 gibberellins reported from widely different organisms such as fungi and higher plants. They are denoted as GA₁, GA₂, GA₃ and so on. However, Gibberellic acid (GA₃) was one of the first gibberellins to be discovered and remains the most intensively studied form. All GAs are acidic. They produce a wide range of physiological responses in the plants. Their ability to cause an increase in length of axis is used to increase the length of grapes stalks. Gibberellins, cause fruits like apple to elongate and improve its shape. They also delay senescence. Thus, the fruits can be left on the tree longer so as to extend the market period. GA₃ is used to speed up the malting process in brewing industry.
NTA tests gibberellins because they are key plant growth regulators that increase axis length and have practical agricultural applications. Students often confuse gibberellins with auxins or think they only affect flowering—but the NCERT explicitly states gibberellins cause axis elongation, fruit development, and delay senescence. The trap is memorizing individual GA types (GA₁, GA₂, GA₃) without understanding their function. Remember: gibberellins are acidic hormones that promote cell elongation and are used commercially in grape stalks and brewing. Focus on their physiological effects: elongation, fruit improvement, and senescence delay—these are testable concepts.
Which plant hormone causes cell elongation, especially in stems? [Neet 2025]
Through deep analysis of NEET and NTA, 88 of 90 questions from the NEET 2026 paper were matched straight from the MedicNEET Biology question bank.
88/90MedicNEET's Biology question bank is built from the same NCERT lines NTA picks repeatedly. Not random MCQs — questions crafted exactly like NTA crafts them.