Permanent tissues and their types - class-XI
Description: permanent tissues and their types | |
Number of Questions: 96 | |
Created by: Akash Patel | |
Tags: organisation of tissues anatomy of flowering plants biology plant tissues introduction to biotechnology plants: structure and function botany histology and anatomy of flowering plants plant tissues and anatomy |
In sclerenchyma, wall is
-
Lignified
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Suberised
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Pectinised
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Cutinised
Sclerenchyma cells are characterized by relatively thick, lignified secondary cell walls. The lignified wall gives sclerenchyma cells their rigidity, and they function primarily in mechanical support and water conduction. They also make up most rigid parts of the plant (e.g., seed coats and some fruit walls) and are often positioned so that they provide mechanical protection for softer plant parts.
Common between sclerenchyma and collenchyma is
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Material transport
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Conduction of water and minerals
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Providing buoyancy
-
Providing support
Which of the following is not related to the structure of stomata?
-
Epidermal cells
-
Guard cells
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Sclerenchyma cells
-
Accessory cells
Sclerenchyma is the supporting tissue in plants. Two types of sclerenchyma cells exist: fibers and sclereids. Their cell walls consist of cellulose, hemicellulose and lignin. Sclerenchyma cells are the principal supporting cells in plant tissues that have ceased elongation where as Stomata are cell structures in the epidermis of tree leaves and needles that are involved in the exchange of carbon dioxide and water between plants and the atmosphere.
Which is not true regarding sclerides?
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Found in shells of nuts, pulp of Guava and Pea
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Stone cells
-
Constituent of sclerenchyma
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Group of living cells
Compare the statements a and b
Statement a. Sclerenchyma cells do not have plasmodesmata
Statement b. Cell walls of some permanent tissues are heavily lignified.
-
Statement a is correct and b is wrong
-
Both the statements a and b are wrong
-
Both the statements a and b are correct
-
Statement a is wrong and b is correct
Plasmodesmata are narrow channels that act as intercellular cytoplasmic bridges to facilitate communication and transport of materials between plant cells and are not found in Sclerenchyma cells. Sclerenchyma fibres are long and narrow and have thick lignified cell walls. They provide mechanical strength to the plant and allow for the conduction of water. Sclereids are specialised sclerenchyma cells with thickened, highly lignified walls with pits running through the walls.
Which of the following pair has lignin?
-
Tracheid and collenchyma
-
Sclerenchyma and sieve tube
-
Sclerenchyma and trachea
-
Parenchyma and endodermis
Sclerenchyma cells have thickened lignified walls, which make them strong and waterproof. The wall of the trachea is considerably thickened and lignified. The characteristic thickening pattern, the thickness and the lignin content of the cell wall provide the vessel rigidity and make it resistant against the collapsing effect of the intense transpiration of the leaves.
Tissue cells commonly found in fruit walls of nuts and pulp of some fruits like guava are called
-
Fibres
-
Sclereids
-
Tracheids
-
Vessels
The spherical, oval or cylindrical cells with very narrow lumen; in sclerenchyma are called sclereids. Sclereids are usually found in the fruit walls of nuts, pulp of fruits like guava, pear and sapota; seed coats of legumes and leaves of tea. The gritty texture of pear or guava is because of sclereids.
Which of the following statements is true?
-
Collenchyma occurs in layers below epidermis in monocot plants
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Xylem parenchyma cells are living, thin walled and lignified
-
Sclerenchyma cells are usually dead and without protoplasts
-
Companion cells are specialised sclerenchyma cells
-
Phloem fibres are generally present in primary phloem
Sclerenchyma tissue is composed of sclerenchyma cells, which are usually dead at maturity (i.e., have lost their protoplasts). They characteristically contain very thick, hard secondary walls lined with lignin; consequently, sclerenchyma provides additional support and strength to the plant body.
Hard lignified thick-walled long and painted cells constitute
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Parenchyma
-
Collenchyma
-
Sclereids
-
Sclerenchyma
Septate sclereides occur in Pereskia in _____________.
-
Pith and cortex
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Xylem
-
Phloem
-
Pericycle
Fibres and sclereids are the types of
-
Parenchyma
-
Collenchyma
-
Sclerenchyma
-
Xylem
Sclerenchyma is the simple permanent tissue present in plants that performs the function of protection and support. Two types of sclerenchyma cells exist, fibers and sclereids. Fibres are long, narrow-lumen, thick-walled and dead cells that provide support to the internal structure of plants. Sclereids are polygonal cells that are found in fruit pulp. Parenchyma has think walled, polygonal and live cells while collenchyma has angular thickened polygonal cells.
Which one is not correct about sclerenchyma?
-
Sclerenchyma fibres associated with xylem tissue are called wood fibres
-
Sclerenchyma fibres associated with phloem tissue are called bast fibres
-
Endocarp of coconut is rich is sclerenchyma fibres
-
Brachysclereids are isodiametric and polygonal
The exocarp is the thin outermost layer (or skin) of the fruit. The mesocarp is a thick husk composed of coarse brown fibers (coir). The endocarp is the hard, but relatively thin woody inner layer of a fruit that contains the endosperm. The endosperm is partly liquid (“coconut water”) and partly solid (fibrous white coconut “flesh” or “meat”, which adheres to the inner wall of the endocarp).
Sclerenchymatic tissues are dead have lignified thickened walls.
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True
-
False
There are four types of tissues present in the plants, namely vascular tissue, epidermal tissue, ground tissue and meristematic tissue. Ground tissue consists of parenchyma tissue, collenchyma tissue and sclerenchyma tissue. Parenchyma cells have thin primary walls and remain alive after they become mature. Collenchyma cells have thin primary walls with secondary thickening in some areas. They provide mechanical and structural support.
Pear fruits are gritty due to occurrence of
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Tracheids
-
Fibres
-
Vessels
-
Sclereids
Sclereids are a reduced form of sclerenchyma cells with highly thickened, lignified cellular walls that form small bundles of durable layers of tissue in most plants. The presence of numerous sclereids form the cores of apples and produce the gritty texture of guavas and pears.
In which of the following sclerenchyma cells, the secondary cell walls are present
-
The cells containing cytoplasm only
-
The cells with protoplast
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Cells which are living at maturity
-
Cells which are non-living at maturity
Sclerenchyma, in plants, support tissue composed of any of various kinds of hard woody cells. Mature sclerenchyma cells are usually dead cells that have heavily thickened secondary walls containing lignin.
A tissue whose cells have very thick cell wall are
-
Parenchyma
-
Aerenchyma
-
Sclerenchyma
-
Both A and B
- A tissue whose cells have very thick cell wall are sclerenchyma.
- The cells wall is rigid and lignified.
Long plants are able to stand erect due to presence of
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Sclerenchyma
-
Collenchyma
-
Parenchyma
-
Prosenchyma
Since plants do not have bones for structure and support they must have cell walls around all of their cells. This leads to the need for very unique cells in plants. Sclerenchyma cells are specialized plant cells that exist to provide strength and support. They are present in all kinds of plants including grasses, trees, and flowering plants.
Sclerenchyma fibres are absent in
-
Protoxylem
-
Protophloem
-
Metaxylem
-
None of the above
Protoxylem and protophloem that develop in the primary stage of plants need living cells to divide and form more tissues to grow and as sclerenchymatous cells are dead and not divide so they lack sclerenchyma cells.
Choose the incorrect statement.
-
Permanent tissues having all cells similar in structure and function are called simple tissue.
-
Complex tissue has different types of cells performing different functions altogether.
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Secondary meristem is lateral meristem.
-
The cells of permanent tissues divide further.
- Permanent tissues may be defined as a group of living or dead cells formed by meristematic tissue and have lost their ability to divide and have permanently placed at fixed positions in the plant body. Meristematic tissues that take up a specific role lose the ability to divide. This process of taking up a permanent shape, size and a function is called cellular differentiation. Cells of meristematic tissue differentiate to form different types of permanent tissues.
- Complex permanent tissue - The complex tissue consists of more than one type of cells which work together as a unit. Complex tissues help in the transportation of organic material, water and minerals up and down the plants. That is why it is also known as conducting and vascular tissue.
- Lateral Meristem - This meristem consists of cells which mainly divide in one plane and cause the organ to increase in diameter and growth. Lateral meristem usually occurs beneath the bark of the tree in the form of Cork Cambium and in vascular bundles of dicots in the form of vascular cambium. The activity of this cambium results in the formation of secondary growth.
Pits are found in the walls of
-
Parenchyma
-
Sclerenchyma
-
Collenchyma
-
Both A and C
Pits are thin portions of the cell wall. Through pits, the communication and exchange of fluid takes place between cells. There is no deposition of lignin in this area. They are found in the walls of dead tissues with lignified cell walls like sclerenchyma and tracheids and vessels of xylem.
Stone cells is an alternative name of
-
Cortical fibres
-
Sclereids
-
Xylary fibres
-
Phloem fibres
A. Cortical fibres are the extraxylary fibres present in cortex.
B. Sclereides are excessively thick walled short sclerenchyma cells.
C. Xylary fibres are the sclerenchyma fibres present in the xylem.
D. Phloem fibres are the sclerenchyma fibres present in the phloem.
So the correct answer is ‘sclereids’.
Sclerenchyma cells have thickening of
-
Cellulose
-
Lignin
-
Silica
-
Cellulose, silica
Sclerenchyma tissue possesses long, narrow cells with thickened walls. They possess secondary walls made of lignin. Lignin is a chemical substance, which acts as cement and hardens them. Therefore, option B is correct.
Simple tissues are_________________
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Parenchyma, xylem and collenchyma
-
Parenchyma, collenchyma and sclerenchyma
-
Parenchyma, xylem and sclerenchyma
-
Parenchyma, xylem and phloem
- Simple permanent tissues are a group of cells with the same origin, structure and function are called simple permanent tissues.
- Parenchyma, collenchyma, and sclerenchyma are simple tissue which coordinates to perform a similar function.
Which simple permanent tissue is formed of dead cells?
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Collenchyma
-
Sclerenchyma
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Aerechyma
-
Xylem
Collenchyma, is the simple permanent mechanical tissue, formed of living cells.
Sclerenchyma, is the simple permanent mechanical tissue, formed of dead cells.
Aerenchyma, is a type of parenchyma, simple permanent tissue, formed of living cells.
Xylem is a simple complex permanent tissue formed of the majority of dead cells.
So, the correct answer is ‘Sclerenchyma’.
Sclereids belong to
-
Xylem
-
Parenchyma
-
Collenchyma
-
Sclerenchyma
Unthickened areas present in the walls of sclerenchyma are
-
Pits
-
Plasmodesmata
-
Junctions
-
Both A and B
Sclerenchyma cells possess pits and plasmodesmata where cell walls are not lignified or thickened. Plasmodesmata aid in cytoplasmic connections in adjacent cells through which transportation of substances occur. Therefore, option D is correct.
Gritness in pulp of fruit like sapota and guava is due to?
-
Parenchyma
-
Sclerenchyma
-
Collenchyma
-
Fibres
The plant tissues commonly found in fruit walls of nuts and pulp of some fruits like guava are termed as
-
Fibers
-
Tracheids
-
Sclereids
-
Vessels
The plant tissues commonly found in fruit walls of nuts and pulp of some fruits like guava are termed as sclereids. Sclereids are a reduced form of sclerenchyma cells with highly thickened, lignified cellular walls that form small bundles of durable layers of tissue in most plants. The presence of numerous sclereids form the cores of apples and produce the gritty texture of pears. Although, sclereids are variable in shape, the cells are generally isodiametric, prosenchymatic, forked or elaborately branched. They can be grouped into bundles, can form complete tubes located at the periphery or can occur as single cells or small groups of cells within parenchyma tissues.
Thus, the correct answer is option C.
Name the tissue that is present in the husk of the coconut.
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Sclerenchyma
-
Parenchyma
-
Collenchyma
-
Aerenchyma
- Sclerenchyma makes plant hard and stiff. The cells of the tissue are dead. They are long and narrow. For example, coconut. The cells of this tissue are dead and its wall is thickened with a chemical substance Lignin. (Lignin is a chemical substance which acts as cement).
- Sclerenchyma is present in the stems, around the vascular bundle in the veins of the leaves and the hard covering of seeds and nuts. It provides strength to the plant parts.
Lignin is a component of the secondary cell walls of
-
Epidermis
-
Collenchyma
-
Sclerenchyma
-
Parenchyma
Lignin is a component of the secondary cell walls of sclerenchyma. Two types of sclerenchyma cells exists- fibres and sclereids. Their walls consist of cellulose, hemicellulose and lignin. Sclerenchyma cells are the principal supporting cells in plant tissues that have ceased elongation.
Cell wall of sclerenchymatous fibres and sclereids are respectively thickened by
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Cellulose, cellulose
-
Cellulose. hemicellulose
-
Lignin, cellulose
-
Lignin, lignin
Fibres and sclereids are two types of sclerenchyma cells. The fibres are generally long, slender cells occurring in bundles. Their walls are thickened by lignin and the principal cell wall material is cellulose. Sclereids are the reduced form of sclerenchyma cells with thickened, lignified walls. So, the correct option is 'lignin, lignin'.
External protective tissues are
-
Cortex and epidermis
-
Cork and pericycle
-
Cortex and pericycle
-
Cork and epidermis
Cork (phellem) is not considered as living tissue. It is a water-resistant, protective tissue that displaces the stem epidermis during the secondary growth phase. A mature cork cell is non-living and has cell walls that are composed of a waxy substance that is highly impermeable to gasses and water called as suberin. Generally, the phloem together with the cork cells is considered to comprise the outer bark. The epidermis cell 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 absorbs water and mineral nutrients. Cortex and pericycle are not the protective tissues.
Thus, the correct answer is option D.
Which one of the following comprises only simple tissues?
-
Parenchyma, collenchyma and sclerenchyma
-
Parenchyma, xylem and collenchyma
-
Parenchyma, xylem and sclerenchyma
-
Parenchyma, xylem and phloem
The ground tissue of plants is the supporting tissue which helps the specialized one to carry their function efficiently. The ground tissue includes parenchyma, sclerenchyma, and collenchyma.
Collenchyma cells have thin primary walls with some areas of secondary thickening. Collenchyma provides extra structural support, particularly in regions of new growth.
Sclerenchyma cells have thick lignified secondary walls and often die when mature. Sclerenchyma provides the main structural support to a plant. Ground tissue is a simple tissue. Xylem and phloem come under vascular bundles.
Thus, the correct answer is option A.
Sclerenchymatous bundle sheath is found in
-
Sunflower
-
Mango
-
Grass
-
Banyan
The bundle sheath of monocot leaf is made of parenchyma but just above and below the vascular bundles are found sclerenchymatous cells up to epidermis. The bundle sheath of dicot leaf made of parenchyma. Just above and below the vascular bundle, some parenchymatous cells or collenchymatous cells are present up to epidermis. Grass belongs to monocot so, contains sclerenchymatous bundle sheath. Sunflower, banyan and mango are dicot so, contains parenchymatous or collenchymatous bundle sheath.
Thus, the correct answer is option C.
Companion cells are specialised type of
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Sclerenchyma cells
-
Lateral meristems
-
Collenchyma cells
-
Parenchyma cells
Companion cells are specialised type of parenchyma cells. The metabolic functioning of sieve-tube members depends on a close association with the companion cells, a specialized form of parenchyma cell. All of the cellular functions of a sieve-tube element are carried out by the (much smaller) companion cell, a typical nucleate plant cell except the companion cell usually has a larger number of ribosomes and mitochondria. The cytoplasm of a companion cell is connected to the sieve-tube element by plasmodesmata.
Tyloses are found in
-
Sclereids
-
Sclerenchyma fibres
-
Secondary phloem
-
Secondary xylem
Tyloses are generally the outgrowth protruding from the parenchyma cells of xylem vessels. It generally protects the vascular tissue during stress like drought or infection. During unfavourable conditions, it falls from the sides of the cells and dam up the vascular tissue to prevent further damage to the plant. It can be traced in the secondary xylem. It aids in the process of making sapwood into heartwood in some hardwood trees, especially in trees with larger vessels. These blockages can be used in addition to gum plugs as soon as vessels become filled with air bubbles, and they help to form a stronger heartwood by slowing the progress of rot.
Thus, the correct answer is option D.
Tissue which develops more due to scarcity of water
-
Sclerenchyma
-
Collenchyma
-
Parenchyma
-
Meristem
Tissue which develops more due to the scarcity of water is sclerenchyma. Sclerenchyma is the supporting tissue in plants. Two types of sclerenchyma cells exist: fibres and sclereids. Their walls consist of cellulose, hemicellulose, and lignin. Sclerenchyma cells are the principal supporting cells in plant tissues that have ceased elongation. Sclerenchyma is composed of dead cells with extremely thick cell walls -secondary walls that make up to 90% of the whole cell volume.
Thus, the correct answer is option A.
Sclerenchymatous cells in their cell walls have large percentage of
-
Cellulose
-
Pectin
-
Lignin
-
Silica
Sclerenchyma is a simple permanent tissue which is mainly composed of dead cells. The walls consist of cellulose, hemicellulose and lignin. These are the principal supporting cells in plant tissues that have ceased elongation.
Fibre (longest plant cell), belongs to which tissue?
-
Parenchyma
-
Collenchyma
-
Sclerenchyma
-
Aerenchyma
Sclerenchyma is a simple permanent tissue which is mainly composed of dead cells. The walls consist of cellulose, hemicellulose and lignin. These are the principal supporting cells in plant tissues that have ceased elongation.
Sclerenchyma fibres are of great economical importance, since they constitute the source material for many fabrics (flax, hemp, jute, ramie).
The function of hypodermis is
-
Protection
-
Hardness
-
Support
-
Storage
The protoderm mainly differentiates to form the dermal layer which is known as epidermis, hypodermis, and endodermis. Hypodermis (exodermis) is the outermost layer of cells in the plant cortex. These cells are modified to give additional structural support or to store food materials or water. After the loss of the piliferous layer of the root, the hypodermis takes over the protective functions of the epidermis.
Thus, the correct answer is option C.
Senescence and death are essential in the function of
-
Sieve tubes
-
Companion cells
-
Both A and B
-
Xylem and sclerenchyma cells
Senescence refers to the loss of functional capacity causing a cellular breakdown and metabolic failure. It is a characteristic feature of the period between reproductive maturity and death of a plant or plant part or cell, which ultimately causes cell death.
Hard, lignified, thick-walled, long and pointed cells constitute
-
Parenchyma
-
Collenchyma
-
Sclereids
-
Sclerenchyma
Sclerenchyma cells have thick lignified secondary walls and often die when mature. It provides the main structural support to a plant. They are long and pointed cells.
Tissue which develops more due to scarcity of water is
-
Sclerenchyma
-
Collenchyma
-
Parenchyma
-
Meristem
Parenchyma is a simple living tissue, which is composed of thin-walled polyhedral, isodiametric living cells with sufficient cytoplasm and one or more nuclei.
The main function of sclerenchyma is to help in the ___________________.
-
Conduction of food
-
Synthesis of food
-
Exchange of gases
-
Mechanical support
Conduction of food from leaves to other parts of the plant is carried out by phloem cells.
The synthesis of food is carried out by chlorenchyma cells. These are parenchyma cells with chlorophyll pigments.
Sclerenchyma is a type of permanent tissue. They are dead, long, thin narrow cells with thickened walls without any internal space. This tissue makes the plant hard and stiff. This aids in mechanical support to plant.
Hard, lignified, thick-walled, long and pointed cells in plants are
-
Parenchyma
-
Sclerenchymatous fibre
-
Collenchyma
-
Sclereids
Sclerenchyma is the simple permanent tissue. It commonly forms the protective covering of the nuts and fruits but it also forms the ground tissue which supports different specialized cells. Their walls consist of cellulose, hemicellulose, and lignin.
Hard, lignified, thick, walled, long and pointed cells in plants are
-
Parenchyma
-
Sclerenchymatous fibre
-
Collenchyma
-
Sclereids
Parenchyma is thin walled, polyhedral, isodiametric, mostly non-lignified, soft living cells with sufficient cytoplasm and one or more nuclei.
Plastids are absent in
-
Parenchyma
-
Mesophyll
-
Sclerenchyma
-
All of the above
Sclerenchyma cell is a simple permanent tissue which is mainly composed of dead cells. It is the hard, thick walls that make sclerenchyma cells important strengthening and supporting elements in plant parts that have ceased elongation. Their cell walls contain, besides cellulose, a high proportion of lignin. It forms a protective coating on seeds and nuts. Since sclerenchyma cells are dead at maturity, it does not contain plastids. Parenchyma and collenchyma cells are living cells which have plastids.
Sclereids or stone cells are modified form of
-
Collenchyma
-
Sclerenchyma
-
Fibers
-
Xylem vessels
Sclereids or stone cells are a reduced form of sclerenchyma cells. It has highly thickened, lignified cellular walls that form small bundles of durable layers of tissue in most plants. They are type of sclerenchyma cell that differs from the fibre cell by not being greatly elongated. Often occurs singly (an idioblast) or in small groups, giving rise to a gritty texture in, for instance, the pear fruit, where it is known as a stone cell. May also occur in layers, for example in hard seed coats. A type of cell with thick cell walls, consisting of lignin, that is commonly found on the outer 'skin' of fruits. So, sclereids or stone cells are modified sclerenchyma.
Sclereids and stone cells are modified
-
Collenchyma
-
Sclerenchyma
-
Fibres
-
Xylem vessels
Sclerenchyma is composed of dead tissue which mainly acts as protective coating on fruits and nuts. The reduced form of sclerenchyma cells with highly thickened, lignified cellular walls are known as sclereids. It forms small bundles of durable layers of tissue in most of the plants.
Senescence and death are essential in the function of
-
Sieve tubes
-
Companion cells
-
Both A and B
-
Xylem and sclerenchyma cells
Senescence is also known as aging. It leads to metabolic degradation. It is the characteristic feature of the period between reproductive maturity and death of a plant or plant part or cell.
Lignified elongated dead cells are__________________.
-
Parenchyma
-
Collenchyma
-
Sclerenchyma
-
None of these
Parenchyma cells are thin-walled, flexible and loosely packed cells. They are alive at maturity. Their shape changes as per function.
Collenchyma cells are living, elongated and irregularly thickened at corners with less intercellular space.
Sclerenchyma is a type of permanent tissue. They are dead, elongated, thin, narrow cells with thickened walls without any internal space. Therefore, option C is correct.
Which of the following is/are composed of dead cells?
-
Sclerenchyma
-
Tracheids
-
Vessels
-
All of the above
- Sclerenchyma cell is a simple permanent tissue which is mainly composed of dead cells. It provides strength and rigidity to the stem.
- It forms the protective covering of nuts and fruits. Their cell walls contain, besides cellulose, a high proportion of lignin.
- It forms a protective coating on seeds and nuts.
Which one of the following plant tissue lacks protoplasm at maturity?
-
Sclerenchyma
-
Collenchyama
-
Parenchyma
-
Epidermis
Collenchyma contains living, elongated cells with protoplasm at maturity.
Parenchyma cells are thin-walled, flexible and loosely packed cells. They are alive at maturity. Their cells show protoplasm at maturity.
Sclerenchyma cells are dead, long, thin, narrow with thickened walls without any internal space. They do not possess any protoplasm at maturity. Hence, option A is correct.
Grittiness of fruit wall is due to the present of_______________
-
Scleride
-
Sclerenchyma fibres
-
Trecheids
-
Collenchyma
- Sclereids are a reduced form of sclerenchyma cells with highly thickened, lignified walls. These have the shape of a star. They are small bundles of sclerenchyma tissue in plants that form durable layers, such as the cores of apples and the gritty texture of pears (Pyrus communis).
- Sclereids are variable in shape. The cells can be isodiametric, prosenchyma, forked or elaborately branched.
- They can be grouped into bundles, can form complete tubes located at the periphery or can occur as single cells or small groups of cells within parenchyma tissues.
- But compared with most fibers, sclereids are relatively short. Sclerenchyma, tracheids, and collenchyma do not cause the Grittiness of the fruit wall.
Husk of coconut is made of_____________
-
Parenchyma
-
Sclerenchyma
-
Collenchyma
-
Chlorenchyma
- Parenchyma forms the major component within organs and are closely packed or have intercellular space and are living with the ability of division. They perform functions of photosynthesis, storage, and secretion.
- Sclerenchyma is long, narrow cells with thick and lignified cell walls having a few or numerous pits. These are commonly found in fruit wall of nuts, the husk of the coconut, seed coat of legumes, etc.
- Collenchyma is found in the hypodermis in dicot plants and provide mechanical support to the plant.
- Chlorenchyma is the modified parenchymatous tissue that helps in photosynthesis.
Plant tissue responsible for stiffness in husk of coconut is
-
Sclerids
-
Phloem cells
-
Xylem fibres
-
Sclerenchyma fibres
The shape of the sclerenchyma cells are elongated and cell walls are thickened by lignin. The plant gets very strong support and strength since these are heavily deposited with lignin. It is responsible for the stiffness of coconut fibres.
Most of the plant tissues are ______ cells.
-
Dead
-
Alive
-
Minute
-
Large
Since dead cells can provide mechanical strength as easily as live ones and need less maintenance.
What is the function of sclerenchymatous tissue?
-
Flexibilty
-
Tenderness
-
Strength
-
All of the above
The chief mechanical tissue of the plant body composed of highly thick walled cell with little or no protoplasm is called as sclerenchyma. The main function of sclerenchymatous tissues is to give support to the plant. It also provides hardness and protective covering to seed and nuts.
Therefore, the correct answer is option C.
Which cells among the permanent tissue are impermeable to water?
-
Parenchyma
-
Collenchyma
-
Both A and B
-
Sclerenchyma
The chief mechanical tissue of the plant body composed of highly thick walled cell with little or no protoplasm is called as sclerenchyma. Sclerenchyma consist of lignin. Lignin deposition is so thick that the cell walls become strong, rigid and impermeable to water.
Which of the following tissues is dead at maturity?
-
Sclerenchyma
-
Collenchyma
-
Parenchyma
-
Both B and C
The chief mechanical tissue of the plant body composed of highly thick walled cell with little or no protoplasm is called as sclerenchyma. The thickening of cell wall is due to deposition of cellulose or lignin or both. Lignin deposited cells are said lignified. Sclerenchyma cells are dead at maturity because of the absence of protoplast.
The cells of sclerenchyma can be classified as
-
Fibres and fibriosis
-
Ligaments
-
Fibre and sclereids
-
None of the above
The chief mechanical tissue of the plant body composed of highly thick walled cell with little or no protoplasm is called as sclerenchyma.
1. Fibres- Fibres are long, elongated sclerenchymatous cells with pointed ends.
2. Sclereids- Sclerenchymatous cells which are short and possess extremely thick lignified walls.
The sclerenchyma cells are thick walled due to the presence of
-
Acetone
-
Lignin
-
Lipids
-
None of the above
The chief mechanical tissue of the plant body composed of highly thick walled cell with little or no protoplasm is called as sclerenchyma. The thickening of cell wall is due to deposition of cellulose or lignin or both. Lignin deposited cells are said lignified.
Which cell is found in the husk of coconut?
-
Xylem
-
Sclerenchyma
-
Collenchyma
-
All of the above
The chief mechanical tissue of the plant body composed of highly thick walled cell with little or no protoplasm is called as sclerenchyma. The thickening of cell wall is due to deposition of cellulose or lignin or both. Lignin deposited cells are said lignified. Sclerenchyma is the tissue which makes the plant hard and stiff.
The osteosclereids are seen in
-
Seed coat of crotalaria
-
Seed coat of pisum
-
Pulp of pyrus
-
Petioles of banana
- Osteosclereids are also known as bone cells. It is a type of sclereid that forms the hypodermal layer in seeds, fruits, and leaves of some plants (dicots).
- It was first seen in the seed coat of Pisum during the maturation. These are the columnar cells that are dilated at the ends.
So, the correct option is B.
Which of the following statement is true?
-
The collenchyma occurs in layers below the epidermis in monocotyledonous plants.
-
Sclerenchyma cells are usually dead and without protoplasts.
-
Xylem parenchyma cells are living and thin walled and their cell walls are made up of lignin.
-
The companion cells are specialized sclerenchymatous cells.
-
Phloem fibres are generally present in the primary phloem.
In stems and leaves of monocots, collenchyma is absent. Instead, sclerenchyma is present in monocots. Xylem parenchyma consists of living cells of parenchyma, which are thick and their secondary cell wall is lignified. Sieve tube member is associated with one or more specialized parenchyma cells called as companion cells. Phloem fibres are generally present in the secondary phloem.
Thus, the correct answer is option B.
Which of the following are simple tissues?
-
Parenchyma, xylem and phloem
-
Parenchyma, collenchyma and sclerenchyma
-
Parenchyma, xylem and collenchyma
-
Parenchyma, xylem and sclerenchyma
Parenchyma, collenchyma and sclerenchyma are called as simple tissues as they are made up of similar kind of cells. Vascular tissue is a complex tissue because it is heterogeneous in nature with different types of cells. The chief elements are xylem, phloem and pericycle.
Thus, the correct answer is option B.
The tissue which has dead cells in the functional state is
-
Collenchyma
-
Sclerenchyma
-
Parenchyma
-
Phloem
- Sclerenchyma cells are dead cells at maturity and have a very thick cell wall due to the deposition of lignin.
- They are either present in the form of fibres or sclereids (stone cells).
- They are located in the leaf veins, hard coverings of the seeds and vascular bundle.
- Its main function include- 1) provide rigidity and mechanical support to the plant body, 2) It also makes the plant stiff and hard.
- So, the correct answer is 'Sclerenchyma'.
Lignin is the main constituent of
-
Woody tissues
-
Growing tissues
-
Phloem
-
Cortex
Fibres are usually long, spindle shaped structures, with tapering or blunt ends. Secondary thickening by lignin occur in 90% of the area of the cell. Fibres are grouped into xylary fibres and extraxylary fibres. Xylary fibres are also called wood fibres and are the longest among xylem elements.
Thus, the correct answer is option A.
Long pointed sclerenchyma cells are
-
Fibres
-
Tracheae
-
Wood parenchyma
-
Sclereids
Sclerenchyma cells occur in many different shapes and sizes, but two main types occur: fibres and sclereids. Fibres are greatly elongated cells whose long, tapering ends interlock, thus providing maximum support to a plant. They often occur in bundles or strands and can be found almost anywhere in the plant body, including the stem, the roots, and the vascular bundles in leaves
A tissue present in guava pulp and tea leaves is
-
Sclereid
-
Chlorenchyma
-
Collenchyma
-
Aerenchyma
- Sclereids or stone cells are a type of reduced sclerenchyma cells.
- These stone cells form hard structures such as seed coats and nut shells and provide support to the soft tissues.
- Their cell wall is highly thickened and lignified which form small bundles of durable layers of tissues.
- The presence of numerous stones cells that makes pear and guava have a gritty texture is brachysclereids (unbranched, short and isodiametric with pits).
- The stone cells in tea leaves that make it tougher are astrosclereids (branched as star-shape).
Which of the following tissues has dead cells?
-
Parenchyma
-
Sclerenchyma
-
Collenchyma
-
Epithelium
Parenchyma cells have thin cellulosic cell walls. Collenchyma cells have thicker cellulosic walls and also may have pectin deposition on corners. Sclerenchyma cells have thick lignified cell walls and are dead at maturity and provide protection to the different parts of the body. Epithelial cells are thin-walled and living.
Sclereids belong to
-
Collenchyma
-
Xylem
-
Sclerenchyma
-
Sclerenchyma fibres.
Sclereids are a reduced form of sclerenchyma cells with highly thickened, lignified cellular walls that form small bundles of durable layers of tissue in most plants.
Stereome is a
-
Vascular tissue
-
Phloem
-
Collenchyma
-
Mechanical tissue
Vascular tissues concerned in the transportation of water, mineral and food.
Phloem is a vascular tissue or conducting tissue, meant for the translocation of organic solutes or food.
Collenchyma is a simple permanent living mechanical tissue, provides elasticity to the young stems.
Mechanical tissues are the rigid cellular tissues, provides elasticity, flexibility to the different parts of the plant body. These are called stereome. So, the correct answer is 'Mechanical tissue’.
Which of the following statements is true?
-
The collenchyma occurs in layers below the epidermis in monocotyledonous plants.
-
Sclerenchyma cells are usually dead and without protoplasts.
-
Xylem parenchyama cells are living and thin walled and their cells walls are made up for lignin.
-
The companion cells are specialised scierenchy matous cells.
Intercellular spaces are absent in sclerenchymatous tissues because___________.
-
They are stratified.
-
They are lignified.
-
They are classified.
-
They are columnar.
Walls of sclerenchyma cells are lignified, which make them thick. Due to this, are no intercellular spaces between them. Hence, option B is correct.
Which of the following tissues has dead cells with thick and lignified cell walls, having a few or numerous pits?
-
Sclerenchyma
-
Collenchyma
-
Phloem
-
None of the above
A. Sclerenchyma is known as the supporting tissue of the plants which make the plant hard and stiff as their cell wall is made up of cellulose, hemicellulose and lignin.
It is difficult to pull out the husk of a coconut tree due to _____________.
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Presence of parenchyma.
-
Presence of sclerenchyma.
-
Presence of collenchyma.
-
Presence of aerenchyma.
Parenchyma cells are thin-walled, flexible and loosely packed cells. They are often alive at maturity. Their shape changes as per function. They are filler tissue in soft parts of a plant.
Collenchyma cells are thin-walled with some areas of secondary thickening. They provide extra structural support and flexibility to plant. Coconut husk is not made of collenchymatous cells.
In many aquatic plants, parenchyma cells have large air cavities to give buoyancy to the plant and enable them to float in water. Such parenchyma cells are called as aerenchyma.
Sclerenchyma is dead, long, thin narrow cells. Walls of sclerenchyma cells are lignified, which make them thick. This tissue makes the plant hard and stiff. Coconut husk is very hard and is made of such thickened, lignified cells. Such cells make it very hard to pull out the coconut husk.
Choose the correct answer from the alternatives given.
Sclerenchymatous cells in their cell walls have large percentage of:
-
silica
-
lignin
-
pectin
-
cellulose
Answer B: Lignin
We get a crunchy and granular feeling, when we chew pear fruit because of the
-
Presence of stone cells (sclerenchyma)
-
Presence of stone cells (parenchyma)
-
Presence of stone cells (collenchyma)
-
Presence of stone cells (aerenchyma)
- Parenchyma cells are alive, thin-walled cells. They are present in soft parts of the plant. But pear fruit has hard parts inside, which give it a gritty texture. Therefore, option B is incorrect.
- Collenchyma cells are thin-walled with some areas of secondary thickening. They provide extra structural support and flexibility to plant. Therefore, option C is incorrect.
- Aerenchyma cells are present in an aquatic plant. Such cells have large air cavities, which enable the plant to float in water.
- Sclereid is a reduced form of sclerenchyma, which has thickened lignified walls. In pear fruit, sclereid cells are present in bundles, which give a gritty texture to the fruit. Such cells are also called "stone cells" because of their hardness.
Which of these cells in a plant is apt to be nonliving?
-
Epidermal
-
Sclerenchyma
-
Collenchyma
-
P
arenchyma
the sclerenchyma tissue is present in stems, around vascular bundles, in the veins of leaves and in the hard covering of seeds and nuts. It is the tissue which makes the plant hard and stiff due to the presence of lignin in the cell wall. The cells of this tissue are dead. So, the correct answer is "sclerenchyma".
-
fruit walls of nuts
-
grit of guava and pear
-
seed coats of legumes
-
all of these
Sclereids are present in fruit walls of nuts, the grit of guava and pear, seed coats of legumes. So, the correct answer is (d).
Cavity or lumen is narrow in
-
Sclerenchyma
-
Parenchyma
-
Collenchyma
-
Tracheids
Parenchyma tissue possess cells with a wide lumen. In aquatic plants, parenchyma cells possess large air cavities, which provide buoyancy to the plant. It enables the plant to float. Hence, option B is incorrect.
Collenchyma tissue contains cell with wide lumen. Hence, option C is incorrect.
Tracheids possess spacious lumen, which extends throughout the length. Hence, option D is incorrect.
Sclerenchyma tissue possess long and narrow cells with narrow lumen. Hence, option A is correct.
Bast fibres are
-
Scelerenchyma fibres
-
Phloem fibres
-
Libriform fibres
-
Fibre tracheids
A. sclerenchyma fibers are long, narrow spindle-shaped sclerenchyma cells having tapering end walls.
B. phloem fibers are sclerenchyma fibers present in the phloem, also called bast fibers.
C. libriform fibers are the typical xylem fibers with thick walls and simple pits.
D. fiber tracheids are xylem fibers intermediate between tracheids and typical sclerenchyma fibers.
so the correct answer is ‘phloem fibers’.
The gritty texture of guava, pear and cheeku is due to the presence of.
-
Phloem parenchyma
-
Sclereids
-
Xylem parenchyma
-
Collenchyma
Sclereids are a reduced form of sclerenchyma cells with highly thickened, lignified cellular walls that form small bundles of durable layers of tissue in most plants. Although sclereids are variable in shape, the cells are generally isodiametric, prosenchymatic, forked, or elaborately branched. They can be grouped into bundles, can form complete tubes located at the periphery, or can occur as single cells or small groups of cells within parenchyma tissues. An isolated sclereid cell is known as an idioblast. Sclereids are typically found in the epidermis, ground tissue, and vascular tissue. The presence of numerous sclereids form the cores of apples and produce the gritty texture of guavas.
Which following statement (s) is/ are true?
(i) Uneven thickening of cell wall is characteristic of sclerenchyma.
(ii) Periblem forms cortex of the stem and the root.
(iii) Tracheids are the chief water transporting elements in gymnosperms.
(iv) Companion cell is devoid of nucleus at maturity.
(v) The Commercial cork is obtained from Quercus suber.
-
(i) and (iv) only
-
(ii) and (v) only
-
(iii) and (iv) only
-
(ii),(iii) and (v) only
Sclerenchyma cells are characterized by relatively thick, lignified secondary cell walls. All plant cells initially have only a primary wall made predominantly of cellulose. As sclerenchyma develops, a secondary wall with a high proportion os lignin is deposited inside a primary wall.
This is a complex, non-carbohydrate polymer found in cell walls Its function is to provide stiffening to the cell as in xylem vessels and bark fibres. Name it
-
Opsonin
-
Saponin
-
Lignin
-
Plant Polypeptide
Lignin is a class of complex organic polymers that form key structural materials in the support tissues of vascular plants and some algae. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Chemically, lignins are cross-linked phenolic polymers. As a biopolymer, lignin is unusual because of its heterogeneity and lack of a defined primary structure. Its most commonly noted function is the support through strengthening of wood (mainly composed of xylem cells and lignified sclerenchyma fibres) in vascular plants.
Hard bast is made up of
-
Collenchyma
-
Sclerenchyma
-
Aerenchyma
-
Parenchyma
Bast is the term used for the fibres of phloem. These fibres are tough and resistant with a narrow lumen and secondary walls deposited with lignin. These are dead elongated cells of sclerenchyma tissue. Examples include jute fibres.
If the pericycle is not continuous but as isolated sclerenchyma strips it is called as
-
Epiblema
-
Phellem
-
Hard bast
-
Astrosclereids
Pericycle is the outermost layer of the stele. Stele is composed of all tissues inside of the endodermis. Structure of pericycle differs in monocots and in dicots. In dicots, pericycle is in the form of isolated strips of sclerenchyma cells, which are lignified. Each patch is associated with phloem of vascular bundle. Such, pericycle is called as hard bast.
Epiblema are special epidermal cells present in rootlets. They are specially adapted for absorbing liquids. Phellem is outermost layer of cork cambium which is suberised.
Astrosclereids is a type of sclereid which is a large, radially branched structure.
Thus, the correct answer is option C.
In case of monocots, hypodermis is
-
Collenchymatous
-
Parenchymatous
-
Sclerenchymatous
-
Both A and B
Hypodermis is present in both dicot and monocot stems. In case of dicots, the hypodermis is made up of collenchyma cells and those present in monocots is made up of sclerenchymatous cells.
Rod-like elongated sclereids in the seed-coats of pulses are called as
-
Astrosclereids
-
Macrosclereids
-
Trichosclereids
-
Brachysclereids
Macrosclereids are elongated sclereids. Sclereids are the reduced form of sclerenchyma. It is usually found in the outer layer of seed coat of legumes. These cells are responsible for restricting water uptake by hard seeded legumes.
Which of the following statement (s) is/are true?
(A) Uneven thickening of cell wall is characteristic of sclerenchyma.
(B) Periblem forms cortex of the stem and the root.
(C) Tracheids are the chief water transporting elements in gymnosperms.
(D) Companion cell is devoid of nucleus at maturity.
(E) The commercial cork is obtained from Quercus suber.
-
A and D only
-
B and E only
-
C and D only
-
B, C and E only
The cortex of the root and shoot is formed from the periblem. The cortex is the outermost layer on the stem or roots of plants. Cork which is used commercially as bottle stoppers, bulletin boards, coasters, insulation, sealing for lids, flooring, gaskets for engines etc. is obtained from Quercus suber, commonly called as the cork oak, a medium-sized, evergreen oak tree. Since the vessel elements are absent in most gymnosperms, the tracheids form the main elements of xylem that help in transporting water and minerals.
Grittness in pear is due to the presence of
-
Brachy sclereids
-
Astro sclereids
-
Ostero sclerids
-
macor sclerids
Sclereids are reduced form of sclerenchyma cells with thick and lignified walls. Grittiness in pear is due to the presence of stone cells called as sclereids. The presence of numberous brachy sclereids makes the texture of pear gritty. The brachy sclereids are isodiametric in shape.
Stereome comprises
-
Sclerenchyma
-
Collenchyma
-
Non-living cells of vascular tissues
-
All of the above
Stereome is a mechanical tissue which is formed due to polysaccharide deposition. This is seen in sclerenchyma, collenchyma and all non-living cells of vascular tissues. The deposition of polysaccharides thickens the cell walls in all the three tissue types. Collenchyma is formed due to the deposition of cellulose and is a living tissue. Sclerenchyma is formed due to the deposition of lignin and is a dead permanent tissue.
What chemical substance is deposited in the secondary wall of sclerenchyma?
-
Myelin
-
Lignin
-
Lymph
-
Collagen
- Sclerenchyma cells are simple permanent tissue which is composed of dead cells and has secondary cell walls thickened with cellulose and usually impregnated with lignin. It serves two major functions protection and support.
Leaves of Victoria regia are rigid due to
-
Stellate parenchyma
-
Stellate sclerenchyma
-
Osteosclereids
-
Macrosclereids
Victoria regia belongs to the genus of water-lilies, from the family Nymphaeceae and inhabits in the still waters of all the rivers of the South American continent. These are characterized by the presence of very large green leaves that are orbiculate, peltate, flat with their margin elevated all around and floating on water surface. The leaves borne on long foot stalks are radiately and reticulately ribbed and the venation of lamina corrugated involute. A cross section reveals the presence of stellate sclerenchyma cells. The sclerenchyma cells with thick nonelastic walls provide the strength and support for these vast leaves
The hypodermis present in maize stem is
-
Parenchymatous
-
Collenchymatous
-
Sclerenchymatous
-
Meristematic
Hypodermis is a part of the outer protective layer in the plant. It is placed below the epidermis.
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. Monocot stem's hypodermis is a region that lies immediately below the epidermis. It is represented by a few layers of compactly arranged sclerenchyma cells. Maize is a monocot.
Thus, the correct answer is option C.