Tag: defense mechanism in plants

 In a typical monocot root, Epiblema is single layered, consists of thin- walled cells. A few tubular root hair arise as unicellular elongation of epiblema cells.

The epidermis is a single layer of cells found on outer layers in different parts of the plant. It forms a barrier between the underlying tissues in a plant with the surrounding environment. Therefore, it is protected from adverse environmental conditions.

The presence of stomata and guard cells in the epidermal tissue will help in the exchange of $O _{2}$ and $CO _{2}$.

Conduction of water and minerals in plants takes place in conducting vessels. It is located in the core, known as xylem. Thus conduction of water is not the function of the epidermis but, it is of xylem.

The correct option is C.

Epidermis usually consists of a single layer of cells and is the outermost layer present on leaves, stem and roots of plants. The epidermis consists of living parenchyma cells. On most plant stem and leaves, cutin, a fatty substance, is very often deposited on the outer surface of the epidermal cell wall to form cuticle over which wax may also be deposited. Generally epidermis is single layered, but in xerophytes it is multilayered'

The epidermis is a single-layered group of cells that covers plants leaves, flowers, roots and stems. It forms a boundary between the plant and the external environment. The epidermis serves several functions, it protects against water loss, regulates gas exchange, secretes metabolic compounds, and especially in roots absorbs water and mineral nutrients. 

Muscle fibre, nerve fibre,and skin are present in the animal body. Epiblema is a special epidermal cells present in rootlets. They are specially adapted for absorbing liquids. Epiblema is present in plants. 

Bulliform cells  are so called because of its peculiar bubble shape. It mainly occurs on the upper surface of the leaves present in grasses. Water present in these cells helps to maintain its shape but loss of turgor pressure during the stress allows the leaves to roll up. During drought, the loss of moisture through vacuoles induces bulliform cells to cause the leaves of many grass species to close as the two edges of the grass blade fold up toward each other. Once adequate water is available, these cells enlarge and the leaves open again. 

Bulliform cells are the special cells known for its peculiar bubble like shape. It is found in the higher plants. The turgor pressure created due to the water present in the cells is lost during stress like transpiration or infection which allows the leaf to roll up. Once adequate water is available, these cells enlarge and the leaves open again. So, bulliform cells are found in the leaf of wheat (grasses) and not in seeds of sunflower, a pod of pea and tuber of potato. Thus, option B is correct.

A cuticle is the waxy layer present on the epidermis of a young stem which generally curtails the water loss by transpiration.

The cuticle is the waxy layer present on the epidermis of the leaf which curtails the rate of water loss by transpiration in certain higher plants. 
Cutin is especially noticeable in many fruits, e.g., apple, nectarine, and cherry, which can be buffed to a high gloss. Carnauba wax is derived from the cuticles of the leaves of Copernicia cerifera, a Brazilian palm.
Suberin is the inert waxy substance which is present in the cell wall of cork tissue.

Passage cells are endodermal in origin. These are found in cells of older roots which have retained thin walls and casparian strips to allow some symplastic flow to the inside. These do not get suberized or thickened.
Experimental evidence suggests that passage cells function to allow transfer of solutes such as calcium and magnesium into the stele, in order to eventually reach the transpiration system. For the most part, however, old roots seal themselves off at the endodermis and only serve as a passageway for water and minerals taken up by younger roots downstream. So, passage cells occur in endodermis and not in pericycle, cortex or epidermis.
Thus, the correct answer is option C.