question 15 The functions of the central vacuoles of plant cells include absorbing and storing water storing nutrient (food) molecules both a and b none 0f the above
The Correct Answer and Explanation is:
The correct answer is both a and b.
The central vacuole is a large, versatile organelle found in mature plant cells, often occupying a significant portion of the cell’s volume. Its functions are critical for the life and structure of the plant. The options provided in the question highlight two of its most essential roles.
First, the central vacuole is paramount for absorbing and storing water. This function is directly linked to maintaining turgor pressure. Turgor pressure is the force exerted by the fluid inside the cell pushing against the rigid cell wall. When the vacuole is full of water, it swells and presses the cytoplasm firmly against the cell wall, making the cell turgid, or firm. This collective turgidity of cells provides structural support to the entire plant, especially in non woody parts like leaves and stems. It is what allows plants to stand upright and keep their leaves positioned to maximize sunlight exposure. When a plant lacks sufficient water, its vacuoles lose water, turgor pressure drops, and the plant wilts.
Second, the central vacuole serves as a storage compartment for a wide array of substances, including nutrient (food) molecules. The fluid within the vacuole, known as cell sap, is a complex solution containing not just water but also ions, salts, amino acids, and sugars. These stored nutrients can be utilized by the cell when needed for metabolic processes. Beyond nutrients, the vacuole also sequesters metabolic waste products, isolating them from the rest of the cytoplasm where they could be harmful. Furthermore, in many plants, vacuoles store pigments, such as the anthocyanins that give flowers their vibrant colors, and defensive compounds to deter herbivores.
Since the central vacuole is responsible for both maintaining water balance for structural support and storing essential nutrients for the cell, the most complete and correct answer is that its functions include both absorbing and storing water and storing nutrient molecules
