Question

The vascular cambium normally gives rise to

• A. Phelloderm
• B. Primary phloem
• C. Secondary xylem
• D. Periderm

Answer 1

The Correct Option is C

To answer the question, let's first understand what the vascular cambium is and its role in plant anatomy. The vascular cambium is a layer of meristematic tissue in plants, primarily responsible for secondary growth. It is located between the primary xylem and primary phloem in dicotyledonous plants and gymnosperms. The function of the vascular cambium is to produce secondary vascular tissues. Specifically, it generates secondary xylem and secondary phloem.

Now, let's analyze the options provided:

1. Phelloderm: This is not produced by the vascular cambium. Instead, it is produced by the cork cambium (also known as the phellogen), which forms part of the periderm in plants.
2. Primary phloem: The primary phloem is part of the primary structure, not secondary. It is initially produced during the growth of the plant from the apical meristem and not the vascular cambium.
3. Secondary xylem: This is precisely what the vascular cambium produces. The secondary xylem is essential for water transport and structural support and forms wood in woody plants.
4. Periderm: The periderm consists of the phellogen, phellem, and phelloderm, and is related to the protective outer layers produced by cork cambium, not the vascular cambium.

Conclusion: The correct answer is Secondary xylem, as the vascular cambium is responsible for giving rise to secondary xylem and secondary phloem.

Tip: Remember that secondary growth in plants, which increases the thickness of stems and roots, is attributed to the activity of the vascular cambium, resulting in secondary xylem and secondary phloem. This is in contrast to primary growth, which involves elongation.