Consider the following statements regarding the function of stomata: 1. They allow the direct intake of nitrogen from the atmosphere. 2. They are involved in the release of oxygen during photosynthesis. 3. They facilitate the loss of water in the form of vapour. Which of the statements given above is/are correct?

The correct option is (c) 2 and 3 only. Explanation Stomata are minute pores found primarily on the epidermis of leaves and young stems. They are bordered by specialized guard cells that regulate the opening and closing of the pore. The primary functions of stomata are to facilitate gas exchange for metabolic processes and to regulate water loss through transpiration. Statement-wise Analysis: - Statement 1 is Incorrect: Plants cannot directly utilize atmospheric nitrogen ($N_2$) through their leaves or stomata. Nitrogen is an essential macronutrient, but it is primarily absorbed from the soil by the roots in the form of nitrate ($NO_3^-$) or ammonium ($NH_4^+$) ions. Atmospheric nitrogen is converted into usable forms through biological nitrogen fixation (by bacteria in root nodules or soil) or industrial processes, not via direct intake through stomata. - Statement 2 is Correct: Stomata are the main site for the exchange of gases between the plant and the atmosphere. During photosynthesis, plants take in carbon dioxide ($CO_2$) and produce oxygen ($O_2$) as a by-product. This oxygen is released into the atmosphere through the stomatal pores. - Statement 3 is Correct: Stomata facilitate transpiration, which is the loss of water in the form of vapour from the aerial parts of the plant. While this process results in water loss, it creates a transpirational pull that is essential for the upward movement of water and dissolved minerals from the roots to the leaves. Key Takeaway: Stomata serve as the gateway for gas exchange (intake of $CO_2$, release of $O_2$) and transpiration (water vapour loss). However, nutrient uptake, specifically nitrogen, occurs through the root system, not the stomata.

NCERT Class 7 Science — Chapter 1: Nutrition in plants

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Consider the following statements regarding the function of stomata:

They allow the direct intake of nitrogen from the atmosphere.
They are involved in the release of oxygen during photosynthesis.
They facilitate the loss of water in the form of vapour.

Which of the statements given above is/are correct?

Official previous-year question

Verified 1 Aug 2026.

Options

A1 and 2 only
B2 only
C2 and 3 only
D1, 2 and 3

Did you get this right?

Solution

The correct option is (c) 2 and 3 only.

Explanation

Stomata are minute pores found primarily on the epidermis of leaves and young stems. They are bordered by specialized guard cells that regulate the opening and closing of the pore. The primary functions of stomata are to facilitate gas exchange for metabolic processes and to regulate water loss through transpiration.

Statement-wise Analysis:

Statement 1 is Incorrect: Plants cannot directly utilize atmospheric nitrogen ($N_2$) through their leaves or stomata. Nitrogen is an essential macronutrient, but it is primarily absorbed from the soil by the roots in the form of nitrate ($NO_3^-$) or ammonium ($NH_4^+$) ions. Atmospheric nitrogen is converted into usable forms through biological nitrogen fixation (by bacteria in root nodules or soil) or industrial processes, not via direct intake through stomata.
Statement 2 is Correct: Stomata are the main site for the exchange of gases between the plant and the atmosphere. During photosynthesis, plants take in carbon dioxide ($CO_2$) and produce oxygen ($O_2$) as a by-product. This oxygen is released into the atmosphere through the stomatal pores.
Statement 3 is Correct: Stomata facilitate transpiration, which is the loss of water in the form of vapour from the aerial parts of the plant. While this process results in water loss, it creates a transpirational pull that is essential for the upward movement of water and dissolved minerals from the roots to the leaves.

Key Takeaway:
Stomata serve as the gateway for gas exchange (intake of $CO_2$, release of $O_2$) and transpiration (water vapour loss). However, nutrient uptake, specifically nitrogen, occurs through the root system, not the stomata.

Your note

More from Chapter 1: Nutrition in plants

With reference to the mode of nutrition in living organisms, consider the following statements: 1. Autotrophic nutrition is the mode where organisms take in food prepared by others. 2. Animals are classified as heterotrophs. 3. The term ‘heterotrophs’ refers to organisms that depend on others for nourishment. Which of the statements given above are correct?

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With reference to the cell structure described in the text, consider the following statements: 1. The cell membrane encloses the cell and controls the movement of substances. 2. The nucleus is a jelly-like substance that fills the entire cell. 3. Cytoplasm is the hard outer covering found only in plant cells. Which of the statements given above is/are correct?

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Consider the following statements about algae: 1. They are generally formed by the growth of organisms in stagnant water. 2. They appear green because they lack chlorophyll. 3. They are autotrophs and can prepare their own food. Which of the statements given above is/are correct?

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Consider the following statements regarding insectivorous plants like the Pitcher plant: 1. They trap insects primarily to obtain carbohydrates. 2. They contain chlorophyll and can perform photosynthesis. 3. The pitcher-like structure is a modified part of the leaf. Which of the statements given above are correct?

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With reference to saprotrophic nutrition, consider the following statements: 1. It is a mode of nutrition where organisms take in nutrients from dead and decaying matter. 2. Fungi ingest dead matter directly without secreting digestive juices. 3. All fungi are harmful and cause spoilage of food and diseases. Which of the statements given above is/are correct?

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The correct option is (c) 2 and 3 only.

Explanation

Statement-wise Analysis:

Statement 1 is Incorrect: Plants cannot directly utilize atmospheric nitrogen ($N_2$) through their leaves or stomata. Nitrogen is an essential macronutrient, but it is primarily absorbed from the soil by the roots in the form of nitrate ($NO_3^-$) or ammonium ($NH_4^+$) ions. Atmospheric nitrogen is converted into usable forms through biological nitrogen fixation (by bacteria in root nodules or soil) or industrial processes, not via direct intake through stomata.
Statement 2 is Correct: Stomata are the main site for the exchange of gases between the plant and the atmosphere. During photosynthesis, plants take in carbon dioxide ($CO_2$) and produce oxygen ($O_2$) as a by-product. This oxygen is released into the atmosphere through the stomatal pores.
Statement 3 is Correct: Stomata facilitate transpiration, which is the loss of water in the form of vapour from the aerial parts of the plant. While this process results in water loss, it creates a transpirational pull that is essential for the upward movement of water and dissolved minerals from the roots to the leaves.