Question

Tracheids differ from other tracheary elements in:

• A. Being imperforate
• B. Lacking nucleus
• C. Being lignified
• D. Having casparian strips

Answer 1

The Correct Option is A

The question asks about how tracheids differ from other tracheary elements. Let's analyze the options provided:

1. Being imperforate: Tracheids are long, tube-like cells found in the xylem of vascular plants. They are indeed imperforate, meaning they do not have perforations or holes in their end walls. This characteristic distinguishes them from vessels, which have perforated end walls to facilitate water movement.
2. Lacking nucleus: Mature tracheary elements, including both tracheids and vessels, lose their nuclei as they develop. Hence, lacking a nucleus is a feature common to all mature xylem elements, not just tracheids.
3. Being lignified: Lignification refers to the strengthening of cell walls with lignin, a complex organic polymer. Both tracheids and vessels are lignified to support the plant and facilitate water transport, so this is not a distinguishing feature.
4. Having casparian strips: Casparian strips are bands of cell wall material found in the endodermal cells of plant roots, not in tracheary elements. Therefore, this characteristic does not apply to tracheids.

Based on these analyses, the correct answer is 'Being imperforate'.

To conclude, tracheids are a type of xylem element that is unique due to their imperforate nature, distinguishing them from vessel elements that have perforations.