In plants zinc takes part in:

Question

Accepted Answer

The correct option is 2:

Zinc is a vital micronutrient for plants, meaning it's required in smaller quantities compared to macronutrients but is absolutely essential for healthy growth and development. One of its most crucial roles is in the activation of a wide array of enzymes within the plant. Enzymes are biological catalysts that speed up metabolic reactions, and zinc acts as a cofactor for many of them. These zinc-activated enzymes are involved in numerous processes, including carbohydrate metabolism, protein synthesis, and nucleic acid synthesis. For example, zinc is a key component of carbonic anhydrase, an enzyme vital for photosynthesis. Without sufficient zinc, these enzymes cannot function optimally, leading to impaired plant growth and various deficiency symptoms.

The incorrect option is 1: Sugar transport.
Sugar transport in plants, primarily sucrose, occurs through the phloem via a process known as pressure flow. This process relies on active transport of sugar into the phloem and osmotic movement of water, but it is not directly mediated by zinc. Boron is more directly involved in sugar transport across membranes.

The incorrect option is 3: Cell elongation.
Cell elongation is largely regulated by plant hormones like auxins and gibberellins. While zinc is involved in the synthesis of auxins (as it is a component of tryptophan, a precursor to auxin), it doesn't directly cause cell elongation itself. Therefore, attributing cell elongation directly to zinc's primary role is inaccurate.

The incorrect option is 4: Pollen germination.
While zinc plays a role in pollen production and viability, particularly through its involvement in auxin synthesis, boron is generally considered the primary micronutrient directly associated with pollen germination and pollen tube growth. Zinc's contribution to pollen germination is more indirect compared to boron's direct involvement.