Casparian strips are the bands of thicknings present on _____walls of endodermis.

Options

A. radial
B. tangential
C. central
D. both a and b

Explanation

To answer the question about Casparian strips, we can follow these steps:

1. **Understanding Casparian Strips**: Casparian strips are specialized structures found in the endodermis of plant roots. They are bands of thickening that play a crucial role in regulating the flow of water and nutrients.

2. **Location of Casparian Strips**: These strips are located on the cell walls of endodermal cells. Specifically, they are found on the walls that face the inner part of the root, which includes both the radial and tangential walls.

3. **Composition of Casparian Strips**: Casparian strips are primarily composed of substances such as lignin, suberin, or cutin, which make the cell walls impermeable to water and solutes, thus forcing them to pass through the cytoplasm of the endodermal cells.

4. **Final Answer**: Since Casparian strips are present on both the radial and tangential walls of the endodermis, the correct response to the question is that they are present on both types of walls.

**Complete Answer**: Casparian strips are the bands of thickening present on both radial and tangential walls of the endodermis.

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