Coconut husk fibres are used for mats which are tough and fibrous. Which tissue has structural features suitable for providing this strength? Explain why living parenchyma couldn't serve the same purpose.
Sclerenchyma tissue has the structural features suitable for providing strength to coconut husk fibres. Sclerenchyma cells have thick walls due to the deposition of lignin, which makes them hard and strong. Most of these cells are dead, contributing to the tough, fibrous nature required for making durable mats.
Parenchyma could not serve the same purpose because it consists of living cells with thin walls. These cells are loosely packed with intercellular spaces, making the tissue soft and lacking the structural rigidity needed for toughness. Parenchyma mainly stores food and performs photosynthesis rather than providing mechanical strength.
Explanation
The textbook context explicitly identifies sclerenchyma as the tissue found in the hard coverings of seeds and nuts, such as coconut husk, due to its lignin-rich thick walls that make it hard and strong. In contrast, parenchyma is described as having thin walls and loose packing, suited for storage and photosynthesis, not for providing structural toughness.
Solution Steps
Step 1: Identify the tissue providing strength in coconut husk as sclerenchyma, based on its thick, lignin-deposited walls that make it hard and strong.
Step 2: Contrast this with parenchyma, noting its thin walls and loosely packed living cells, which make it unsuitable for providing structural toughness.