Permanent Tissue Questions in English

(A) Parenchyma is a type of simple permanent tissue that forms the major component of organs in plants.
It consists of relatively unspecialized cells with thin cell walls made of cellulose.
These cells are living and perform various functions such as photosynthesis,storage,and secretion.
The pulp of fruits is primarily composed of parenchymatous cells,which are often rich in starch,sugars,or water,serving as storage tissue.

(D) Raphides are needle-like crystals of $Calcium$ oxalate found in the cells of many plants.
These crystals serve as a defense mechanism against herbivores and are stored in specialized cells called idioblasts.
Therefore, the correct option is $D$.

(A) Druse is a specific form of crystal deposit found in plant cells.
These are typically composed of calcium oxalate.
Along with Raphides,which are needle-like crystals,Druses are common crystalline inclusions in plants such as $Pistia$ and various other species.

(B) The parenchyma cells associated with the phloem are known as phloem parenchyma.
These cells are generally absent in most monocotyledonous plants,including the monocot stem.
Therefore,the correct option is $B$.

(C) . The term collenchyma was coined by Schleiden $(1839)$.
Collenchyma occurs chiefly in the hypodermis of dicotyledonous stems (e.g.,$Cucurbita$,$Helianthus$) and leaves.
They are usually absent in monocots and in roots.

(A) Collenchyma is a type of simple permanent tissue that provides mechanical support to the growing parts of the plant.
In dicot stems,collenchyma is typically found in the hypodermis,which is the layer just below the epidermis.
It is absent in monocot stems (where sclerenchyma is present in the hypodermis) and is generally absent in roots.
Therefore,the correct answer is $A$ (Dicot stem).

(B) The first formed primary xylem is known as protoxylem.
In protoxylem,the secondary wall thickenings are generally simple to allow for the elongation of the organ as it grows.
These thickenings are typically of the $Annular$ (ring-like) or $Helical$ (spiral) type.
In contrast,the later formed primary xylem,known as metaxylem,typically exhibits more complex thickenings like $Scalariform$,$Reticulate$,or $Pitted$ types.

(A) $Parenchyma$ is considered the most primitive tissue from both phylogenetic (evolutionary history) and ontogenetic (developmental origin) points of view.
It consists of simple,undifferentiated cells with thin primary cell walls,which serve as the precursor for more specialized tissues like $Collenchyma$ and $Sclerenchyma$.

(D) $Sclereids$ are a type of sclerenchyma cells that are lignified and possess extremely thick walls.
Due to the heavy deposition of lignin, the cell lumen is almost obliterated.
These cells lack living protoplasm at maturity.
They are typically isodiametric or irregular in shape (spherical, oval, cylindrical, $T$-shaped, or stellate) and are commonly found in the hard parts of plants, such as fruit walls of nuts, pulp of guavas, and seed coats of legumes.

(D) Laticiferous cells are specialized cells or vessels found in certain plants that produce and store latex.
These cells contain a milky fluid called latex,which is a complex mixture containing various substances such as proteins,alkaloids,starches,sugars,oils,tannins,resins,and gums.
Since latex serves as a storage site for both metabolic products (food reserves) and secondary metabolites (often considered waste or defense compounds),the most accurate description is that they contain food and waste materials.

(B) In certain water-conducting tissues like tracheids and vessels,the secondary cell wall deposition does not occur uniformly.
These thickenings often appear as irregular,swollen,or bead-like structures along the inner surface of the cell wall.
These specific types of wall thickenings are referred to as tertiary wall deposits,which provide additional mechanical strength to the xylem elements.

(B) typical parenchyma cell is a simple permanent plant cell that contains a nucleus,a large central vacuole,and a cell wall.
While some parenchyma cells may contain chloroplasts (known as chlorenchyma),a 'typical' or generalized parenchyma cell is defined by its basic structure and does not necessarily contain chloroplasts.
Therefore,the most appropriate answer among the given options is that a typical parenchyma cell does not necessarily contain chloroplasts.

(A) In mature $Sieve \text{ } tubes$, the nucleus is absent to facilitate the efficient transport of food materials through the phloem.
Companion cells, however, contain a nucleus and regulate the metabolic activities of the sieve tubes.
Chlorenchyma cells are living parenchyma cells containing chloroplasts and possess a nucleus.
Therefore, the correct answer is $A$.

(C) The conducting tissues in plants are known as vascular tissues.
$Xylem$ is responsible for the conduction of water and minerals from the roots to the aerial parts of the plant.
$Phloem$ is responsible for the translocation of food (organic nutrients) from the leaves to other parts of the plant.
Therefore,both $Xylem$ and $Phloem$ are considered the conducting tissues of plants.

(D) The phloem tissue consists of four types of elements: sieve tube elements,companion cells,phloem parenchyma,and phloem fibers.
Among these,sieve tube elements,companion cells,and phloem parenchyma are living cells at maturity.
Phloem fibers are the only dead component of the phloem tissue.
Therefore,all the options listed ($A$,$B$,and $C$) are living components of the phloem.

(A) Xylem is a complex permanent tissue composed of four types of cells: tracheids,vessels (trachea),xylem fibres,and xylem parenchyma.
Among these,tracheids,vessels,and xylem fibres are dead cells at maturity because they lack protoplasm.
$Xylem$ parenchyma (also known as wood parenchyma) is the only living component of the xylem,as these cells possess a nucleus and cytoplasm.

(C) The correct answer is $C$. Sieve tubes are living cells that lack a nucleus at maturity but retain a thin layer of cytoplasm and a plasma membrane. Because they are living and lack thick secondary lignified walls (unlike vessels,tracheids,or fibres),their cell walls are more extensible and flexible to facilitate the transport of food materials.

(D) Young sieve tube elements contain a nucleus,ribosomes,and other organelles,which are gradually lost as they mature. In their young,undifferentiated state,they possess a dense cytoplasm and organelles that are structurally similar to other living plant cells. However,they do not resemble $Mycoplasma$,$Slime$ $body$,or $Golgi$ $body$ in their fundamental nature. Therefore,the correct answer is $D$.

(B) In plant anatomy,$Vessels$ (tracheary elements) are typically characterized by a wider lumen to facilitate efficient water conduction. In contrast,$Sieve$ $tubes$ (phloem elements) generally possess a comparatively narrower lumen compared to the wide,hollow vessels found in the xylem. Therefore,$Sieve$ $tubes$ have a narrower lumen.

(A) $Xylem$ is the primary water-conducting tissue in vascular plants.
It is also referred to as $Hadrom$.
$Leptom$ is another term used for $Phloem$,which is responsible for food conduction.
$Bast$ is a common term for the $Phloem$ fibers found in the bark of plants.
Therefore,the correct term for the water-conducting part is $Hadrom$.

(D) The living cells in plants possess a plasma membrane,which acts as a semipermeable membrane. Among the given options,vessels,tracheids,and fibres are dead cells at maturity and lack a functional plasma membrane. Wood parenchyma cells are living cells that contain a protoplast enclosed by a plasma membrane,which functions as a semipermeable membrane.

(D) Bordered pits are specialized structures found in the cell walls of tracheary elements,which include both tracheids and vessel elements. These structures facilitate the lateral movement of water between adjacent xylem cells,thereby playing a crucial role in the ascent of sap and water transport in plants. Since tracheary elements are the primary conducting tissues of the xylem,option $(d)$ is the most comprehensive and correct answer.

(D) The sieve plates are the perforated end walls of sieve tube elements in the phloem. During the maturation of a sieve tube element,the transverse end walls develop numerous small pores,making them sufficiently porous to allow the translocation of food materials (sucrose) from one sieve tube element to the next. Therefore,the correct description is that they are sufficiently porous.

(A) Callus (often referred to in the context of sieve plates) is composed of $Callose$.
$Callose$ is a $\beta-1,3-glucan$ polysaccharide.
In plant sieve tubes,cytoplasmic strands passing through the sieve pores are often encased in a cylinder of $Callose$,which helps in regulating the transport of materials.

(B) callus pad is a mass of undifferentiated cells that develops at the site of injury or grafting in plants.
In the context of plant anatomy and wound healing,the formation of a callus pad is primarily associated with the phloem tissue.
When the phloem is injured,the living cells within it (such as phloem parenchyma) undergo rapid division to form a callus,which helps in sealing the wound and restoring the continuity of the tissue.
Therefore,the correct answer is $Phloem$.

(C) Sieve tube elements are specialized cells of the phloem that lack a nucleus at maturity but retain a thin layer of cytoplasm along the cell wall. This cytoplasm is connected to adjacent companion cells through cytoplasmic strands that pass through the sieve pores. Tracheids,vessels,and wood fibers are dead cells at maturity and do not contain cytoplasm.

(A) Callose is a polysaccharide that accumulates in the sieve pores of sieve tubes.
During the winter season or when the sieve tubes become old,the sieve pores get plugged with callose,which is a carbohydrate polymer.
This process is known as the formation of callose plugs.
These plugs reduce or stop the transport of food materials through the phloem.
Therefore,callose plugs are primarily formed in old sieve tubes.

(D) Phloem is a complex permanent tissue responsible for the translocation of food in plants.
It is composed of four main types of cells: $1.$ Sieve tubes,$2.$ Companion cells,$3.$ Phloem parenchyma,and $4.$ Phloem fibres (which are sclerenchymatous).
Since sieve tubes,phloem parenchyma,and phloem fibres (sclerenchyma) are all components of phloem,the correct answer is $D$.

(C) Phloem tissue is a complex permanent tissue.
It is composed of four different types of cells: sieve tubes,companion cells,phloem parenchyma,and phloem fibres.
Since it is made up of more than one type of cell working together as a unit to perform a specific function,it is classified as a complex permanent tissue.

(D) Sieve tubes are the primary conducting elements of the phloem in angiosperms. They are living cells that transport organic nutrients (sucrose) from the source to the sink. Because they are under high turgor pressure and contain a nutrient-rich fluid known as phloem sap,they exude this sap when cut or injured.

(C) Plant hormones (phytohormones) are chemical substances produced by specific living tissues in plants to regulate growth and development.
$Xylem$ is a complex permanent tissue primarily responsible for the conduction of water and minerals. It does not synthesize hormones.
$Sclerenchyma$ is a simple permanent tissue consisting of dead cells at maturity,which provides mechanical support to the plant. It is metabolically inactive and does not produce hormones.
Since both $Xylem$ and $Sclerenchyma$ are structural tissues that do not participate in hormone synthesis,the correct answer is $C$.

(A) In aquatic plants (hydrophytes),the intercellular spaces in parenchyma develop to a considerable extent to form a connected system throughout the plant body.
Such a modified parenchymatous tissue is called aerenchyma.
It helps in the circulation of air (gaseous exchange) as well as provides buoyancy to the plants,allowing them to float on the water surface.

(C) Mechanical tissues,such as collenchyma and sclerenchyma,provide structural support and rigidity to plants.
These tissues are best developed in $Xerophytes$ because they need to withstand harsh environmental conditions,such as strong winds and water scarcity,which require a robust and rigid plant body to prevent wilting and mechanical damage.

(B) Vessels (tracheae) are a characteristic feature of the xylem in angiosperms. While they are typically absent in most gymnosperms,the order $Gnetales$ (e.g.,$Gnetum$,$Ephedra$,and $Welwitschia$) is a notable exception where vessels are present. Therefore,vessels are found in most angiosperms and some gymnosperms.

(D) The $Sieve$ $tube$ $element$ is a specialized cell found in the phloem tissue of angiosperms. During its maturation process,the $Sieve$ $tube$ $element$ loses its nucleus,ribosomes,and vacuoles to facilitate the efficient transport of food materials (sucrose) through the plant. Therefore,a mature $Sieve$ $tube$ $element$ is considered an enucleated cell.

(C) Lignification is the process of deposition of lignin,a complex polymer,in the cell wall of plant cells.
Lignin provides structural support and rigidity to the cell wall.
As the cell wall becomes heavily lignified,it becomes impermeable to water and nutrients.
Due to this lack of transport,the protoplast eventually degenerates,and the cell becomes dead.
This is characteristic of cells like tracheids,vessels,and sclerenchyma fibers.

(C) Suberin is a complex,hydrophobic,fatty substance that is deposited in the cell walls of certain plant tissues,such as cork cells (phellem) and the endodermis (Casparian strips). It is typically associated with the secondary cell wall,providing waterproofing and protection against pathogens and water loss.

(B) The cell wall of plants is a complex structure.
$1$. The $Primary \ cell \ wall$ is the first layer formed,which is thin and flexible.
$2$. The $Secondary \ cell \ wall$ is formed internal to the primary wall as the cell matures. It is thick and rigid,and it is characterized by the deposition of $Lignin$,which provides mechanical strength to the plant tissues,especially in xylem vessels and tracheids.
$3$. The $Middle \ lamella$ is the outermost layer that acts as a glue to hold adjacent cells together,primarily composed of calcium and magnesium pectates.
Therefore,lignin deposition is a hallmark of the secondary cell wall.

(A) $1$. $\text{Vessels}$ are long, cylindrical, tube-like structures made up of many cells called vessel members, each with lignified walls and a large central cavity (lumen).
$2$. Since they are composed of multiple vessel members, they are multicellular.
$3$. $\text{Tracheids}$ are elongated or tube-like cells with thick and lignified walls and tapering ends. They are individual cells, meaning they are unicellular.
$4$. Therefore, vessels with a wide lumen are multicellular, which makes option $A$ the correct statement.

(B) The seed coat of legumes (like peas or beans) contains specialized sclerenchyma cells known as macrosclereids.
These are elongated,rod-shaped cells that provide mechanical strength and protection to the seed.
$A$. Astrosclereids are star-shaped.
$B$. Macrosclereids are rod-shaped and found in seed coats.
$C$. Trichosclereids are hair-like.
$D$. Brachysclereids are stone cells that are isodiametric.

(B) In mature $Xylem$ tissue,the $Vessel$ $element$ (or $Vessel$) is a dead cell that lacks a nucleus and a central vacuole at maturity.
This allows for the efficient transport of water and minerals through the plant body.
$Cambium$ $cells$ are meristematic and contain a nucleus and vacuoles.
$Root$ $hair$ cells are living epidermal extensions with a nucleus and a large vacuole.
$Companion$ $cells$ are specialized parenchyma cells associated with sieve tubes and contain a dense cytoplasm,a nucleus,and vacuoles.

(B) Both vessel elements (xylem) and sieve tube elements (phloem) are specialized conducting cells in plants.
At maturity,both cell types lose their nucleus to facilitate the efficient transport of water (in vessels) and food (in sieve tubes).
Therefore,the lack of a nucleus is a common structural feature shared by these mature conducting elements.

(C) The gritty or granular texture of the edible part of a pear (Pyrus communis) is caused by the presence of stone cells or sclereids.
Specifically,these are known as Brachysclereids or stone cells.
Brachysclereids are short,isodiametric sclereids that provide mechanical support and hardness to the fruit tissue.
Macrosclereids are rod-shaped,Osteosclereids are bone-shaped,and Malpighian cells are specialized cells found in the seed coat of legumes.

(D) Bast fibers are also known as phloem fibers.
These are sclerenchymatous cells that are generally absent in primary phloem but are found in secondary phloem.
They provide mechanical support to the plant body.
Therefore, they are obtained from the phloem tissue of the woody stem.

(B) In plant anatomy,the evolution of xylem elements shows a transition from tracheids to vessels. Tracheids are considered the more primitive conducting elements found in all vascular plants. Vessels are more efficient at water conduction and are considered an advanced or derived character,primarily found in angiosperms.

(C) Companion cells are specialized parenchymatous cells that are closely associated with sieve tube elements.
These cells are characteristic features of the phloem in Angiosperms.
In Pteridophytes and Gymnosperms,companion cells are absent; instead,they have specialized cells called albuminous cells (or Strasburger cells) that perform similar functions.

(B) The translocation of food (organic solutes) in plants occurs through the phloem tissue.
Within the phloem, the $Sieve \text{ } tube$ elements are the primary conducting cells responsible for the transport of sugars and other organic nutrients from source to sink.
$Parenchyma$ is involved in storage, $Xylem \text{ } vessel$ is involved in water transport, and $Fibers$ provide mechanical support.

(A) The term $Leptom$ (or $Leptome$) is a botanical term used to describe the conducting tissue of the phloem.
It specifically refers to the sieve elements (sieve cells or sieve tube elements) that are responsible for the translocation of organic nutrients (food) within the plant.
Therefore,$Leptom$ represents the conducting part of the phloem.

(A) Tracheids are elongated or tube-like cells with thick and lignified walls and tapering ends. Their end walls are not open but possess pits,which allow the movement of water between adjacent cells.
In contrast,vessels are long cylindrical tube-like structures made up of many cells called vessel members,each with lignified walls and a large central cavity. The end walls of vessel members are perforated,allowing for the efficient transport of water.

(A) Xylem fibers are sclerenchymatous cells associated with the xylem tissue. They provide mechanical support to the plant. These fibers are commonly found in the secondary xylem of many plants,contributing to the strength of the wood.