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Botany Question 15 – AP-EAMCET 2025

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Assertion (A): Trichomes help in preventing water loss due to transpiration. Reason (R): The specialized cells near the guard cells together constituted stomatal apparatus. Identify the correct option from the following

Consider the various structural adaptations plants have evolved to minimize water loss, such as trichomes and stomata.

Step 1: Evaluate the truthfulness of Assertion (A)✦ Active

Assertion (A) states: "Trichomes help in preventing water loss due to transpiration." Trichomes are epidermal outgrowths on plant surfaces. They reduce transpiration by increasing the boundary layer resistance, reflecting sunlight, and trapping a layer of humid air near the leaf surface. This reduces the water potential gradient between the leaf and the atmosphere, thereby decreasing water loss. Thus, Assertion (A) is a true statement.

Step 2: Evaluate the truthfulness of Reason (R)○ Expand

Reason (R) states: "The specialized cells near the guard cells together constituted stomatal apparatus." The stomatal apparatus consists of the stomatal pore, the two guard cells that regulate its opening and closing, and the specialized epidermal cells surrounding the guard cells, known as subsidiary or accessory cells. These components collectively form the stomatal apparatus. Thus, Reason (R) is also a true statement.

Step 3: Determine if Reason (R) is the correct explanation for Assertion (A)○ Expand

We have established that both Assertion (A) and Reason (R) are true statements. Now, we need to check if Reason (R) provides a correct explanation for Assertion (A). Assertion (A) discusses the role of trichomes in preventing water loss. Reason (R) defines the components of the stomatal apparatus. While both relate to plant structures and water regulation, the definition of the stomatal apparatus does not explain the mechanism by which trichomes prevent water loss. There is no direct cause-and-effect relationship or explanatory link between the two statements. Therefore, Reason (R) is not the correct explanation for Assertion (A).

💡 Teacher's Secret Hint

Remember that for R to be a correct explanation for A, it must directly answer 'why' A is true.

Step 4: Select the correct option○ Expand

Based on our analysis, Assertion (A) is true, and Reason (R) is true, but Reason (R) is not the correct explanation for Assertion (A). This corresponds to option 2.

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