Dermatogen, periblem, and plerome areA) Permanent tissuesB) Meristematic tissues C) Intercalary tissuesD) Secondary tissues

The correct answer is: B) Meristematic tissues
Dermatogen, periblem, and plerome are terms used to describe the different regions of the apical meristem in plants, which is the tissue responsible for the growth of the plant. These regions are meristematic in nature, meaning they consist of cells that can actively divide to produce new cells for plant growth.
Understanding the Terms:
1. Dermatogen:
o Dermatogen is the outermost layer of the apical meristem, and it gives rise to the epidermis of the plant, the outer protective layer of cells.
o This region plays a crucial role in the formation of tissues that will protect the plant from environmental factors like water loss and pathogens.
2. Periblem:
o Periblem is the layer just inside the dermatogen. It contributes to the formation of the ground tissues, including the cortex and other supportive tissues.
o The cells in the periblem differentiate to form various types of parenchyma tissues that are important for storage, support, and metabolic processes in plants.
3. Plerome:
o Plerome is the innermost region of the apical meristem. It gives rise to the vascular tissues, such as the xylem (responsible for water transport) and phloem (responsible for the transport of nutrients and sugars).
o The plerome plays a key role in forming the plant's vascular system, essential for the conduction of water, minerals, and food throughout the plant.
Why These Are Meristematic Tissues:
• Meristematic tissues are specialized tissues in plants that contain actively dividing cells. These tissues are responsible for growth by producing new cells, which then differentiate into various permanent tissues of the plant (like epidermis, vascular tissue, and ground tissue).
• Dermatogen, periblem, and plerome are all regions of the apical meristem, which is a region of actively dividing cells located at the tips of roots and shoots. Therefore, these three regions are meristematic tissues because they are directly involved in plant growth through cell division and differentiation.
Why the Other Options Are Incorrect:
• A) Permanent tissues:
o Permanent tissues are formed when the cells of meristematic tissues stop dividing and differentiate into specialized cells. Dermatogen, periblem, and plerome are not permanent tissues; rather, they are regions of the meristem where new cells are produced before they become differentiated into permanent tissues.
• C) Intercalary tissues:
o Intercalary tissues are found between mature tissues and are responsible for growth in specific parts of the plant, such as at the base of leaves or internodes. While intercalary meristems can contribute to growth, dermatogen, periblem, and plerome are not classified as intercalary meristems but as part of the apical meristem.
• D) Secondary tissues:
o Secondary tissues are those formed later in the life of a plant, typically by lateral meristems such as the vascular cambium and cork cambium, which contribute to the secondary growth in plants. Dermatogen, periblem, and plerome are part of the primary meristem, not secondary tissues.
Dermatogen, periblem, and plerome are regions of the apical meristem, which are responsible for primary growth in plants. They consist of actively dividing cells and are thus classified as meristematic tissues. Therefore, the correct answer is B) Meristematic tissues.