Kinds of plant tissue - class-XI

 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.

Cotton, seed hair fibre of a variety of plants of the genus Gossypium, belonging to the hibiscus, or mallow family (Malvaceae) and native to most subtropical parts of the world. Cotton is a soft, fluffy staple fibre that grows in a boll or protective capsule, around the seeds of cotton plants of the genus Gossypium in the family of Malvaceae.
The fibre is almost pure cellulose. Under natural conditions, the cotton bolls will tend to increase the dispersion of the seeds. The epidermis cells 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. Cotton fibres are collected from epidermal layer of seeds. So, cotton fibres are epidermal hairs of seed and not epidermal hairs of fruits, fibres taken out from roots or fibres taken out from the stem. 
Thus, the correct answer is option B.

The epidermal tissues system forms the outer protective covering of primary plant body in form of epidermis and of secondary plant organs in form of periderm. 

The apical meristematic tissue is continuously dividing tissue which mainly helps forms different specialized cells. Periblem is the histogen in plants that gives rise to the cortex. It does not give rise to the epidermis, pericycle, and the pith. It is the multilayered zone that lies beneath the dermatogen. The periblem cells divide into anticlinal and periclinal planes and give rise to cortex and endodermis. Pleurome gives rise to pericycle, vascular tissues, pith and medullary rays. Dermatogen gives rise to an epidermal layer of plant organs. 
Thus, the correct answer is option B.

The bark is composed of periderm and stem's secondary phloem, the cork cambium, phelloderm and cork cells together make up the periderm. Formation of new periderm layer renders the previous layer dead due to stoppage of water and nutrient supply and differentiates the bark into two regions, namely outer and inner bark. The cork, secondary cortex and phloem present just outside the innermost phellogen constitute outer bark while rest of the tissues present in the outer bark make inner bark. Formation of subsequent periderm layers as overlapping scales gives scaly bark as is present in Psidium. When the bark is peeled off as large sheets, it is termed as intermediate bark as is found in Eucalyptus and Betula.
Thus, the correct answer is option C.

The epidermis cells are the cells which form the outer layer and plays an important role in protection. It helps to prevent the water loss by transpiration. Nerium, is a xerophyte which has layers of epidermal tissue to curtail the rate of transpiration. It is a type of xerophytic adaptation.
Thus, the correct answer is option D.

Prostele is a primitive and simple type of stele. It consists of a solid mass of xylem surrounded by phloem, pericycle, and endodermis. It is permanently present in adult stems of many living pteridophytes, e.g. Lygodium, Lycopodium, Hymemophyllus, and Selaginella. It is present in vascular plants. Protostele is of four types as haplostele, actinostele, plectostele and mixed protostele. Thus, option C is correct.

Laticiferous vessels are the specialized thin walled parenchymatous cells that secrete latex and are found in the cortex. They lack pits and are composed of cellulose and hemicelluloses and serve to secrete latex. Epidermis is the outermost covering of the primary plant body and is mostly represented by a single layer of compactly arranged, barrel-shaped parenchyma cells.
The innermost layer of cortex forms endodermis which has compactly arranged barrel shaped cells. The primary thin walled endodermis shows suberin deposition in form of bands or strips that run around the radial and end walls of the cells and forms casparian strips. Vascular bundle consists of xylem, phloem and cambium (in dicot only) which are derived from procambium and serve in translocation of food and sap.
Thus, the correct answer is option A.

Hypodermis lies below the epidermis. These cells are sometimes modified to give additional structural support or to store food materials or water. Since its cell walls are heavily suberized and impermeable to water its apparent function is to keep the water and nutrients from leaking out through the cortex. The hypodermis is especially well developed in plants of arid regions and in those with shallow root systems. It also deters the entrance of soil microorganisms. So, the function of hypodermis is support and not storage, hardness or protection. Thus, option C is correct.

Epidermis is the outermost covering of the primary plant body and is mostly represented by a single layer of compactly arranged, barrel-shaped parenchyma cells that delimit cotex on outer side.  

Scaly bark refers to the type of bark of trees where the stem has discontinuous, overlapping successive periderms and patches of the bark are shed. This is generally found in Eucalyptus squamosa growing in and around Sydney.

Epidermal cells make the outermost covering of primary plant body. They are compactly arranged, barrel-shaped parenchyma cells with no or little intercellular spaces. 

Suberin is a waterproofing waxy layer. Its main function is to serve as a barrier to movement of water and solutes. A mature cork cell is nonliving and has cell walls that are composed of a waxy substance that is highly impermeable to gasses and water, called as suberin. Thus, option B is correct. 

The apical meristem has upper promeristem and lower primary meristem. Primary meristem differentiates into three distinct meristematic regions, the outermost protoderm, middle ground meristem, and innermost procambium. The protoderm gives rise to epidermal tissue system, ground meristem forms cortex/ground tissue system and procambium forms vascular tissue system (xylem, phloem, and cambium). 

Epidermis is the outermost protective layer which minimizes the loss of water by transpiration. Some plants, like Ficus elastica and Peperomia, which have periclinal cellular division within the protoderm of the leaves, have an epidermis with multiple cell layers.

Each stomatal pore is surrounded by two guard cells that assist in stomatal opening driven by turgidity of guard cells. The only epidermal cells with unevenly thickened walls and chloroplasts are the guard cells, they are kidney shaped in dicots and dumbell shaped in monocots.

Epidermis is the part of epidermal tissue system and forms the outer protective covering of primary plant body. The epidermal cells secrete cutin, which is a hydrophobic substance and prevents water loss and desiccation. The cutin forms a covering outside the epidermal cells in all plants parts except root.

• Cork cells are dead and have cell walls composed of a waxy substance "suberin", which is highly impermeable to gases and water. This substance prevents water loss from stem. Therefore, option B is correct.

The ground tissue system synthesizes organic compounds, supports the plant and provides storage for the plant. It is mostly made up of parenchyma cells. Parenchyma cells synthesize and store organic products in a plant. Parenchyma cells in leaves control photosynthesis. Collenchyma cells have a support function in plants, particularly in young plants. Mesophyll tissue is the photosynthetic parenchyma cells that lie between the upper and lower epidermis layers of a leaf. In dicotyledonous leaves, there are two types of mesophyll cells; palisade mesophyll and spongy mesophyll.

• In deserts, water is scarce and saving water is a major step which plants of this region have to undertake. So in many of the desert plants like Yucca, creosote, cactus, etc, the epidermis has a thick waxy coating of cutin. 
• This restricts the loss of water through transpiration. In desert plants, the epidermis has a thick waterproof coating that is not made of suberin, elastin or chondrin. 

The epidermis cells is a single layer of cells that covers the leaves, flowers, roots and stems of plants. It forms a boundary between the plant and the external environment. Cork cambium is a tissue found in many vascular plants as part of the periderm. The cork cambium is a lateral meristem and is responsible for secondary growth that replaces the epidermis in roots and stems. The pericycle is a cylinder of parenchyma or sclerenchyma cells that lies just inside the endodermis and is the outer most part of the stele of plants. Cortex, in plants, the tissue of unspecialized cells lying between the epidermis (surface cells) and the vascular, or conducting, tissues of stems and roots. 

• Cork cells are formed as a part of the bark. The waterproof waxy layer present on the cork cell is the suberin., Quercus suber. Its main function is as a barrier to the movement of water and solutes. Suberin is highly hydrophobic and a somewhat 'rubbery' material. In roots, suberin is deposited in the radial and transverse cell walls of the endodermal cells. 
• This structure, known as the Casparian strip or Casparian band, functions to prevent water and nutrients taken up by the root from entering the stele through the apoplast. Pectin, lignin, and cellulose are not hydrophobic materials. 

A root hair is the minute structures generally, present on the stem and the roots. It is a tubular outgrowth of a trichoblast, a hair-forming cell on the epidermis of a plant root.

• The epidermis is the outermost covering and acts as a protective layer. it is formed initially by protoderm. 
• These are thin-walled as they are generally made up of parenchymatous cells. 
• 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. 
• The epidermal tissue includes several differentiated cell types of epidermal cells, guard cells, subsidiary cells, and epidermal hairs (trichomes). They have thin-walled cells. 

The epidermis is the outermost cellular layer which covers the whole plant structure, i.e., it covers roots, stem, leaves, flowers and fruit. It is composed of a single layer of living cells, although there are exceptions. Epidermis is usually closely packed, without intercellular spaces or chloroplasts. The outer walls, which are exposed to the atmosphere and usually thickened and may be covered by a waxy, waterproof cuticle which are made up of cutin. So, their side walls stick together due to the wax secretion. 

The epidermis is the outermost cellular layer which covers the whole plant structure, i.e., it covers roots, stem, leaves, flowers and fruit. It is composed of a single layer of living cells, although there are exceptions.

A conspicuous part of the primary structure of many roots is the endodermis, the innermost layer of the cortex, the walls of which often become conspicuously thickened, plus strips of suberized tissue on the radial walls called as 'Casparian strips.'

The epidermis is a single layer of cells that covers the leaves, flowers, roots and stems of plants. It forms a boundary between the plant and the external environment. Its main function is protection. It has small opening known as stomata.

Epidermal cells are typically tightly packed and lack a middle lamella between them in the same way that parenchyma or other tissues do, as they are often directly adjacent.

• Epidermis is the outermost layer of the plant body. It carries out functions as follows:

• Lignin is a substance, which is impermeable to water. It is absent in cork cells.
• Pectin is not present in cork cells. 
• Hemicellulose is permeable to water and gases.
• Cork cells are dead and have cell walls composed of a waxy substance "suberin", which is highly impermeable to gases and water. This substance prevents water loss from the stem. 

Bulliform cells or motor cells are large, bubble-shaped epidermal cells that occur in groups on the upper surface of the leaves of many grasses. Loss of turgor pressure in these cells causes leaves to roll up during water stress. 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. Folded leaves offer less exposure to sunlight, so they are heated less thus, reducing evaporation and conserving the remaining water in the plant and occur on the leaves of many monocotyledons but are probably best known in grasses. They are thought to play a role in the unfolding of developing leaves and in the rolling and unrolling of mature leaves in response to alternating wet and dry periods. So, motor cells helps in inward rolling of leaves and not in transpiration or guttation. 
Thus, the correct answer is option A.

The periderm is the secondary protective dermal tissue that replaces the epidermis during growth in thickness of stems and roots of gymnosperms and dicotyledons i.e., secondary growth. 

Astrosclerieds is a sclereid having its cell wall drawn out into lobes or arms to form a more or less stellate body. It is found in certain xerophytes. Nymphaea contains large intercellular spaces, which occur in the petiole. These airspaces are surrounded by long columns of parenchyma cells. The columnar cells contain chloroplasts and are presumably photosynthetic. Part of a large astroscleried can be seen cutting across one of the parenchymatous fingers. These sclereids add some mechanical strength to fragile structure. 

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. 

Two or more tissues together constitutes the tissue system. The activities of the constituent tissues are responsible for the major function, although they are different in structure and origin. All the different type of tissues in a plant that perform the similar basic function, irrespective of their location is known as tissue system. 

The grass leaves are linear in shape and sessile and are rough in texture due to the presence of cork cells in the epidermis and deposition of silica material. The process of deposition of silica material over the epidermis is known as silicification. It checks the transpiration rate and prevents the entry of pathogens and gives stiffness to the lamina.

Histogen theory (By Hanstein 1870) concludes that shoot apical meristem consists three distinct zones. 

A lenticel is mainly the opening present on the periderm of the secondarily thickened organs and the bark of woody stems and roots of dicotyledonous flowering plants. It is a porous tissue consisting of cells with large intercellular spaces. It helps in the direct exchange of gasses between the internal tissues and atmosphere through the bark, which is otherwise impermeable to gasses. Lenticels are found in most of the woody trees but absent is  woody climbers. If lenticels are blocked then root will die first due to lack of gaseous exchange. Thus, option C is correct.

A vascular bundle is a part of the transport system in vascular plants. The transport itself happens in vascular tissue, which exists in two forms: xylem and phloem. These are generally present in the veins of the leaf where the xylem channelizes the water and phloem conducts the prepared food from the source to the sink.

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 present in only monocot leaf and absent in dicot leaf. 
Thus, the correct answer is option A.

Laticiferous vessels are the specialized thin walled parenchymatous cells that secrete latex and are found in the cortex. They lack pits and are composed of cellulose and hemicelluloses and serve to secrete latex. 

Vascular bundles of the plant show vascular cambium or cork cambium. Cork cambium is involved in making cork. Cork is a nonliving, water resistant tissue formed in many plants to prevent water loss. Cork cells are dead and have cell walls composed of a waxy substance "suberin" which is highly impermeable to gasses and water. This substance prevents the water loss from the stem. Cork also protects the plant from wear and tear. Hence, it is a protective type of tissue. Therefore, option A is correct.  

The epidermis is the outermost cellular layer which covers the whole plant structure, i.e. it covers roots, stem, leaves, flowers, and fruit. It is composed of a single layer of living cells. The outer walls, which are exposed to the atmosphere and usually thickened, are covered by a waxy, waterproof cuticle which is made up of cutin. The waxy cuticle prevents the loss of moisture from the leaves and stems. During drought, the plant hormone abscisic acid (ABA) triggers stomatal closure, thus reducing water loss.

In some higher plants, the cuticle is a water-impervious protective layer covering the epidermal cells of leaves and other parts and limiting water loss. It consists of cutin, a waxy, water-repellent substance allied to suberin, which is found in the cell walls of corky tissue. Cutin is especially noticeable on many fruits—e.g., apple, nectarine, and cherry, which can be buffed to a high gloss. 

A root hair, or absorbent hair, the rhizoid of a vascular plant, is a tubular outgrowth of a trichoblast, a hair-forming cell on the epidermis of a plant root. In root epidermis, epidermal hairs, termed root hairs are common and are specialized for absorption of water and mineral nutrients. In plants with secondary growth, the epidermis of roots and stems is usually replaced by a periderm through the action of a cork cambium. 

Trichomes or hairs grow out from the epidermis in many species. In root epidermis, epidermal hairs, termed root hairs are common and are specialized for absorption of water and mineral nutrients. Guard Cells are the only epidermal cells that can make sugar. As a result, water from other cells enter the guard cells by osmosis so they swell and become turgid. 

Epidermis is a single layer of cells found on outer layers in different parts of a plant, viz., leaves, flowers, roots, stem, etc.  Its functions are as follows,

Three concentric regions of primary meristematic tissues develop immediately behind the apical meristem . These primary meristems produce the different tissues of the plant body: the outermost protoderm differentiates into the epidermis, a tissue that protects the plant; the adjacent ground meristem differentiates into the central ground tissues (the pith and cortex); and the procambium differentiates into the vascular tissues (the xylem, phloem, and vascular cambium).

Dicot roots have xylem in the center of the root and phloem outside the xylem. Phloem is surrounded by the pericycle followed by endodermis. Pericycle is made up parenchyma cells and sclerenchyma cells.
The cortex is the outer most layer of the dicot root. Cortex is made up of epithelium cells. Pith is absent in it. Hence, total 5 types of tissues are present within dicot root.

Parenchyma, collenchyma, and sclerenchyma are called simple tissues. And they are made up of similar kinds of cells. Vascular tissues are complex tissue as it is heterogeneous in nature with different types of cells. The main elements are the xylem, phloem and pericyclic.

Thus, the correct option is B.

Parenchyma form basic packing tissue but unspecialized function so many times in some plant it stores food.  

A. Cuticle: It is a fatty substance( cutin) deposited over the surface of epidermal cells in the form of a separate layer. Usually, the cuticle is covered with wax which may be deposited in the form of granules, rods, crusts or viscous semi-liquid masses.

Mineral salts are transported from the roots to the rest of the plant through the xylem tissue. This movement is part of the ascending stream of water driven by transpirational pull.

Xylem is the specialized vascular tissue responsible for the upward transport of water and dissolved mineral nutrients from the roots to the leaves.

While the xylem is the tissue responsible for conduction, the question asks for the plant part. The stem is the organ that facilitates the conduction of water and minerals between the roots and the leaves.

The multi-directional flow of a variety of organic and inorganic solutes occurs through 'phloem'.

Cells forming the vessels are heavily ligniifed, dead, that is with no protoplasm and nucleus, forming a continuous lacuna by dissolution of the separating walls. 

Parenchyma is the simple permanent plant tissue and it contains non-specialized cells with thin cell walls. Parenchyma helps in storing food and providing support to the plants. The parenchyma of stem and roots helps to store the water and nutrient.

Collenchyma tissue is made up of elongated cells with irregularly thickened walls. Xylem is the tissue in the vascular plants. Its cells have thick, hard walls. Xylem tissue dies soon after its production. Phloem, are also called bast, tissues in plants that conduct the foods made in the leaves to its all other parts.

So answer A is correct.