3. ______ is impermeable to water. 1) Cutin 2) Suberin 3) Lignin 4) Cellulose
Answer (1)
The term 'impermeable to water' refers to a material or substance that does not allow water to pass through it. In the context of plant biology, several substances produced by plants can serve this function, helping to protect plant tissues from water loss.
Here's an explanation of each option:
Cutin : Cutin is a waxy substance found in the cuticle of plants. It helps to form a protective layer that covers the epidermis of leaves, stems, and other organs, reducing water loss and providing some resistance to pathogen entry.
Suberin : Suberin is a complex polymer found in the cell walls of cork and certain underground parts of plants, like roots. It is highly hydrophobic and plays a crucial role in making tissues impermeable to water, thus preventing water and solute loss.
Lignin : Lignin is a complex organic polymer found in the cell walls of many plants, particularly in wood and bark. While it adds strength and rigidity to plant cells, it is not specifically known for impermeability to water.
Cellulose : Cellulose is a polysaccharide that forms the primary structural component of plant cell walls. It is not impermeable to water; instead, it allows some flexibility and permeability.
Given this information, the correct choice for what is impermeable to water is Suberin (2) . Suberin's hydrophobic nature makes it particularly effective in providing a barrier to water movement, especially in the cork cells of bark and some root cells.
