Question

Lenticels are developed by the activity of

• A. Vascular Cambium
• B. Phellogen
• C. Dermatogen
• D. Intercalary Meristem

Answer 1

The correct option is B

Phellogen

The correct option is B.

Explanation for correct option:

1. Small pores occurring on the epidermis of stems, fruits, and petioles are known as lenticels.
2. They are always open, allowing gases and water vapor to pass through.
3. A periderm layer is developed on the bark of trees as a secondary development, and it is made up of three layers: phellem, phellogen, and phelloderm.
4. Lenticels are formed when the phellogen layer divides rapidly, leaving voids between them.
5. The nearby cells are called companion cells.

Explanation for Incorrect option:

Option A:

1. The vascular cambium is the major growth tissue in the stems and roots of many plants, particularly dicots like buttercups and oak trees, gymnosperms like pine trees, and vascular plants like sunflowers.
2. Secondary xylem is produced inwardly, towards the pith, and secondary phloem is produced outwards, towards the bark.

Option C:

1. The primary meristem found at the shoot and root terminals of plants is dermatogen.
2. The apical meristematic tissues give them their shape.
3. According to the histogen theory, they form the outermost layer of a plant or a plant portion.

Option D:

1. The internodes or base of the leaves are where the intercalary meristems are found.
2. Intercalary meristems contribute to the lengthening of the internode.
3. Monocotyledonous plants are the most commonly affected.

Final answer: Lenticels are developed by the activity of Phellogen.