Direction: In the following questions, a statement of assertion (A) i...
Cells of bark are dead and compactly arranged without intercellular spaces. They have a chemical called suberin in their walls that make them impervious to gases and water.
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Direction: In the following questions, a statement of assertion (A) i...
Assertion: Bark of trees are impervious to gases and water.
Reason: Cells of bark have suberin in their walls.
To understand the given assertion and reason, let's break it down into two parts:
1. Bark of trees are impervious to gases and water:
- The bark is the protective outer covering of the trunk, branches, and stems of trees.
- It acts as a protective barrier, preventing the entry of harmful substances, including gases and water, into the inner tissues of the tree.
- This protection is important for the tree's survival, as excessive water absorption can lead to rot and damage to the inner tissues, while the entry of gases can interfere with the tree's metabolic processes.
2. Cells of bark have suberin in their walls:
- Suberin is a waxy substance found in the cell walls of bark cells.
- It is a complex polymer that is hydrophobic, meaning it repels water.
- Suberin also acts as a barrier to gases, preventing their diffusion through the cell walls.
- This makes the bark impermeable to both water and gases, providing additional protection to the inner tissues of the tree.
From the above explanations, it is clear that both the assertion and reason are true. The bark of trees is indeed impervious to gases and water, and this is because the cells of the bark have suberin in their walls. The presence of suberin in the cell walls makes the bark impermeable to gases and water, acting as a protective barrier for the tree.
Therefore, the correct answer is option A: Both assertion (A) and reason (R) are true, and reason (R) is the correct explanation of assertion (A).
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