The innermost layer of the root cortex is the a. core. b. pericycle. c. endodermis. d. pith.

Verified step by step guidance

1. Identify the region of the root being described: The innermost layer of the root cortex is specified in the question.
2. Recall the structure of a root: The root typically consists of the epidermis, cortex, and vascular cylinder from the outside to the inside.
3. Understand the role of the endodermis: The endodermis is the innermost layer of the cortex that regulates the flow of water and nutrients into the vascular cylinder.
4. Eliminate other options: 'Core' and 'pith' are not standard terms used for the innermost layer of the root cortex. The 'pericycle' is a layer inside the endodermis, surrounding the vascular tissues.
5. Conclude the correct answer: The correct answer is 'c. endodermis' as it is the innermost layer of the root cortex.

Key Concepts

Root Cortex Structure

The root cortex is the outer layer of the root, situated between the epidermis and the vascular tissue. It primarily functions in storage and transport of nutrients and water. Understanding the structure of the root cortex is essential for identifying its innermost layer.

Endodermis

The endodermis is the innermost layer of the root cortex, acting as a selective barrier that regulates the flow of water and nutrients into the vascular system. It contains the Casparian strip, a band of cell wall material that is impregnated with suberin, which helps control the movement of substances.

Pericycle

The pericycle is a layer of cells located just inside the endodermis and is involved in the formation of lateral roots. It plays a role in the growth and development of the root system, but it is not the innermost layer of the root cortex, which is crucial for answering the question.