Problem 43 - Objective Biology for NEET

Question

In plants, respiration takes place (a) Only in leaves during night (b) Only in leaves during day (c) In all living cells (d) None of these

Step-by-Step Solution

Answer

The correct answer is (c) In all living cells.

Step 1: Understand the biological process of respiration

Respiration is a vital process for all living organisms, where oxygen is used to break down glucose and produce energy. This process takes place in every cell of the organism.

Step 2: Understand the characteristics of plant respiration

In plants, respiration happens in all living cells, not specific to leaves. Although the photosynthesis process mainly occurs in leaves during the day, respiration is an ongoing process that happens day and night.

Step 3: Select the correct answer based on our understanding

Based on this knowledge, the answer that correctly states where respiration takes place in plants is (c) In all living cells.

Key Concepts

Photosynthesis

Photosynthesis is the process by which green plants, algae, and certain bacteria convert light energy into chemical energy. It happens primarily in the chloroplasts of plant leaves. Through photosynthesis, plants use sunlight, carbon dioxide (CO_2), and water (H_2O) to produce glucose and oxygen (O_2).
This process is essential for plant growth as glucose serves as the primary energy source for plants and an essential building block for growth. The oxygen released during photosynthesis is crucial for the survival of most living organisms on earth, as it provides the oxygen they need for respiration.
Photosynthesis mainly happens during the daytime when sunlight is available. It can be summarized by the formula:
\[\text{6CO}_2 + 6\text{H}_2\text{O} + \text{light energy} \rightarrow \text{C}_6\text{H}_12\text{O}_6 + 6\text{O}_2\]
This process is foundational not only for the plants themselves but also for maintaining the atmospheric balance of oxygen and carbon dioxide.

Cellular Respiration

Cellular respiration is the process by which cells obtain energy from glucose. In plants, this process occurs in all cells, not just in specific parts like the leaves. During cellular respiration, glucose is broken down with the help of oxygen to release energy.
The energy produced is stored in the form of adenosine triphosphate (ATP), which cells use to perform various functions. The equation for cellular respiration is:
\[\text{C}_6\text{H}_12\text{O}_6 + 6\text{O}_2 \rightarrow 6\text{CO}_2 + 6\text{H}_2\text{O} + \text{ATP}\]
It's important to note that cellular respiration occurs continuously both in the day and at night, and is essential for plant survival since it ensures an energy supply even when photosynthesis can't occur, such as in the absence of light.
In summary, while photosynthesis builds up energy stores, respiration is a vital process that releases energy when plants need it.

Plant Biology

Plant biology explores the complex structures, functions, growth, and reproduction of plants. It also looks into how plants interact with their environment and other living organisms.
Key areas of plant biology include metabolism, where processes like photosynthesis and respiration occur. Both contribute to a plant's energy balance and overall health.

• Structure and function: Plants have specialized cells and tissues that support growth and reproduction. Leaves, stems, and roots each play significant roles.
• Growth and development: This involves stages from seed germination to maturity, encompassing processes like photosynthesis and cellular respiration.
• Interaction with environment: Plants adapt to environmental conditions like light, temperature, and water availability, which impact their metabolic processes.

Understanding plant biology is crucial for agriculture, conservation, and managing environments. It helps us make informed decisions about how we can support plant health and sustainability.