Problem 55 - Objective Biology for NEET

Question

Wilting of a plant results from excessive (a) Respiration (b) Photosynthesis (c) Absorption (d) Transpiration

Step-by-Step Solution

Answer

The wilting of a plant results from excessive Transpiration.

Step 1: Understand the Plant Processes

In context to the functions of a plant, Photosynthesis is the process where a plant, using sunlight, converts carbon dioxide and water into glucose and oxygen. Respiration is where a plant breaks down glucose in the presence of oxygen to produce energy. Absorption relates to the intake of water and nutrients from the soil through roots. Finally, Transpiration is the process of water movement through a plant and its evaporation from arial parts, such as leaves, stems and flowers.

Step 2: Identify the Correct Process

Among all the mentioned processes, the one that can lead to wilting when in excess is transpiration. This is due to the fact that wilting of a plant is typically a response to water loss. If a plant is transpiring more than it is being absorbed or if the water is not being replaced, then the plant starts to wilt. Thus, the correct answer is Transpiration.

Step 3: Finalize the Answer

Considering all the facts, when a plant loses more water than it absorbs, which happens due to excessive transpiration, the plant wilts. Hence, the answer is (d) Transpiration.

Key Concepts

Plant Respiration

Plant respiration is a vital process for plant life. It is how plants break down food to get energy, similar to how humans breathe. Unlike photosynthesis, which only occurs in the presence of light, respiration happens all the time, day and night. Plants absorb oxygen from the air, and with this oxygen, they break down glucose, which was previously made during photosynthesis. This breakdown process releases carbon dioxide, water, and energy. The energy released during respiration is used for growth and various other activities within the plant.

Think of plant respiration like the engine in a car. Just as a car needs fuel to run, plants need energy to perform their functions. This energy is crucial for maintaining cellular processes and supporting new cell growth. It’s a continuous process and keeps the plant alive and functioning.

Photosynthesis Process

The photosynthesis process is how plants use sunlight to create their food. It's an incredible natural process that not only provides energy to the plants but also produces oxygen, which is essential for life on Earth.

In photosynthesis, plants take in carbon dioxide from the air and water from the soil. Using sunlight absorbed by their leaves, they create glucose, a type of sugar, and release oxygen as a byproduct.

This process occurs mainly in the leaves, where cells called chloroplasts are abundant. Chloroplasts contain chlorophyll, the pigment that gives plants their green color and captures the energy from sunlight.

• Photosynthesis provides the plant with food in the form of glucose, which can be used immediately or stored for later use.
• The oxygen released is crucial for the respiration of most living organisms on the planet.

Photosynthesis is essential because it forms the base of the food chain. It's how energy from the sun is captured and made accessible to all living creatures.

Water Absorption in Plants

Water absorption in plants is a key process that ensures their survival. Water is primarily absorbed through the plant's roots from the soil. These roots are designed to penetrate the soil and maximize water uptake.

Roots have tiny hair-like structures called root hairs, which increase the surface area for absorption and allow for more efficient water and nutrient intake. This process is essential for several reasons:

• Water is a crucial component of photosynthesis, as it is one of the reactants used to produce glucose.
• It helps in the transportation of nutrients and minerals from the soil to different parts of the plant.
• Water maintains plant structure by providing turgor pressure in cells, preventing wilting.

Without adequate water absorption, plants cannot maintain their physiological processes, leading to distress and potential wilting, especially if water loss through transpiration is not replenished. Proper water balance is therefore critical in maintaining healthy plant growth.