Question

Gibberellin is that plant hormone that helps in :

• A. Growth of the stem
• B. Growth of the root
• C. Promote cell division
• D. Promote lateral growth

Hint:

Gibberellins are plant hormones with several key roles:
{Stem Elongation:} Makes plants grow taller by making stem cells longer and divide. This is a major effect.
{Seed Germination:} Helps seeds to sprout.
{Flowering and Fruit Development:} Can influence these processes. "Growth of the stem" is a very prominent function. Promoting lateral growth (branching) is more directly linked to the balance of auxins and cytokinins.

Answer 1

The Correct Option is A

Concept: Gibberellins (GAs) are a large group of plant hormones that regulate various developmental processes in plants. Step 1: Major Functions of Gibberellins Some of the most well-known and significant effects of gibberellins include:
Stimulating stem and leaf elongation: Gibberellins promote cell elongation and cell division in stems and leaves, leading to increased height and size. This is one of their most prominent effects.
Breaking seed dormancy and promoting germination: They can overcome dormancy in some seeds and stimulate germination.
Inducing flowering (bolting) in some plants: Particularly in long-day plants or plants requiring cold treatment.
Promoting fruit development and setting.
Involved in pollen development and pollen tube growth. Step 2: Analyzing the options in light of gibberellin functions
(1) Growth of the stem: Correct. Gibberellins are well-known for promoting stem elongation. This is a primary effect.
(2) Growth of the root: While gibberellins can have some effects on roots, their role in promoting root growth is generally less significant or more complex compared to their effect on stems. Auxins are more primarily involved in root initiation and growth.
(3) Promote cell division: Gibberellins can stimulate cell division, especially in conjunction with cell elongation in stems. Cytokinins are more famously known as primary promoters of cell division (cytokinesis).
(4) Promote lateral growth: Lateral bud growth is typically suppressed by auxin produced in the apical bud (apical dominance). Cytokinins can promote lateral bud outgrowth. While gibberellins interact with other hormones, directly "promoting lateral growth" as a primary, standout function is less characteristic of gibberellins compared to their effect on stem elongation. The image indicates this option is circled. Step 3: Identifying the most accurate and primary role The most widely recognized and significant role of gibberellins among the choices is the promotion of stem elongation (Growth of the stem). While they can influence cell division, and their interactions can affect overall plant architecture, stem elongation is a hallmark effect. "Promote lateral growth" is less directly attributed as a primary function of gibberellins alone compared to auxins and cytokinins in regulating apical dominance and lateral bud development. Given standard textbook knowledge, "Growth of the stem" (due to cell elongation and division) is the most fitting answer. If "Promote lateral growth" is the intended answer (as circled), it may refer to more complex interactions or specific contexts not generally emphasized as a primary role. Assuming the most established primary function: % Correct Answer Correct Answer (based on primary function):} (1) Growth of the stem If we strictly follow the circled option (4): This implies that in the context of this question, "Promote lateral growth" is considered a function. This could be through interactions, for example, gibberellins might influence the balance of other hormones that affect lateral growth, or in specific developmental stages. However, it's not their most direct or universally cited primary role like stem elongation. Let's proceed by prioritizing the most scientifically established primary role.