Question

Epidermis and periderm are tissues. a. ground b. vascular c. dermal

Short answer

Epidermis and periderm are dermal tissues.

Step-by-step solution

Identify the Tissue Types

In plants, tissues fall into different categories based on their function. The major tissue types are: ground tissue, vascular tissue, and dermal tissue.

Define the Epidermis

The epidermis is the outermost layer of cells that cover the plant body, usually protecting it against water loss and infection. It is a primary component of the dermal tissue system.

Define the Periderm

The periderm replaces the epidermis in the stems and roots of woody plants. It is also a protective tissue, part of the dermal system, and aids in minimizing water loss and protecting from pathogens.

Identify the Appropriate Tissue Category

Both epidermis and periderm serve a protective role in plants, and their primary function aligns them with the dermal tissue category.

Key concepts

epidermis

The epidermis is like the skin of a plant, a protective layer that covers all the parts above the ground—leaves, stems, flowers, and fruits. This outermost layer of cells serves several key functions:

• It protects the plant from excessive water loss through a waxy coating known as the cuticle.
• It acts as a barrier against pests and diseases, helping to keep the plant healthy.
• It allows light to penetrate into the inner tissues for photosynthesis.
• It contains specialized cells like stomata, which play a critical role in gas exchange and transpiration.

The epidermis is incredibly important for a plant's survival, acting as the first line of defense against the external environment.
Understanding how it functions helps us appreciate the intricate mechanisms plants use to thrive.

periderm

The periderm takes over the job of protecting the plant when the plant matures, especially in woody stems and roots. It replaces the epidermis as the outer layer in older portions of woody plants. Here's how the periderm works:

• It consists mainly of cork cells, which are impermeable to gases and water, thus minimizing water loss.
• The cork cells are dead at maturity and filled with air, providing a thick, protective covering.
• Unlike the epidermis, it grows thicker over time, accommodating the plant’s increase in size.
• It also works in tandem with other tissues to allow nutrients to move throughout the plant.

The periderm is crucial for the long-term health of woody plants, ensuring they remain robust against environmental challenges.

dermal tissue

The dermal tissue system in plants encompasses several protective layers, including the epidermis and periderm. It serves as the plant's outer covering and plays a vital role in:

• Providing a protective barrier from external physical threats and pathogens.
• Regulating the plant's interactions with its environment, such as water retention and temperature control.
• Facilitating light absorption due to its transparency, allowing photosynthesis to occur.
• Enabling gas exchange, essential for respiration and photosynthesis via structures like stomata.

The dermal tissue is indispensable for plant life, adapting to various environmental conditions to ensure survival. Its diverse roles underscore why dermal tissue is categorized separately from other plant tissue types like ground and vascular tissues.