Root Questions in English

(D) Adventitious roots are roots that arise from parts of the plant other than the radicle. In $Sweet \text{ } potato$ $(Ipomoea \text{ } batatas)$, the adventitious roots become swollen and store food, serving as a storage organ for the plant. In contrast, $Carrot$, $Turnip$, and $Radish$ possess tap roots that become modified for food storage.

(B) Supporting roots that emerge from the lower nodes of the stem in plants like sugarcane and maize are known as stilt roots. These roots provide additional mechanical support to the plant,preventing it from falling over due to its height or external forces.

(B) In $Rhizophora$,which grows in swampy areas,roots are modified into specialized structures called pneumatophores.
These roots grow vertically upwards (negatively geotropic) to help in the respiration of the plant by absorbing oxygen from the atmosphere.

(A) The hanging structures that grow from the branches of the banyan tree $(Ficus \text{ } benghalensis)$ towards the ground to provide mechanical support are known as prop roots. These are a type of adventitious root.

(A) Root hairs are unicellular outgrowths of the epidermis (epiblema) of the root,making their origin exogenous.
Lateral roots originate from the pericycle,which is an internal layer of the root,making their origin endogenous.

(A) Radicle leaves are leaves that arise directly from the root system (often associated with taproot modifications).
Radish,carrot,and turnip are examples of plants with taproot systems where leaves arise from the root base (radicle).
Maize is a monocotyledonous plant that possesses a fibrous root system and does not produce radicle leaves.
Therefore,maize is the odd one out.

(D) $Cuscuta$,$Viscum$ and $Orobanche$ are parasitic plants.
These plants possess specialized root structures known as haustorial roots (or haustoria).
These roots penetrate the tissues of the host plant to absorb nutrients,water,and minerals directly from the host's vascular system.

(B) $Cuscuta$ is a parasitic plant that develops haustorial roots to absorb nutrients from the host plant.
$Rhizophora$ grows in swampy areas and develops respiratory roots (pneumatophores) for gas exchange.
$Vanda$ is an epiphytic orchid that possesses hygroscopic roots (velamen roots) to absorb moisture from the atmosphere.
$Pandanus$ (screw pine) develops stilt roots that arise from the lower nodes of the stem to provide mechanical support.
Therefore, the correct matching is $a(iii), b(iv), c(i), d(ii)$.

(D) The Assertion is incorrect because prop roots (e.g.,in Banyan tree) are pillar-like and show vertical growth,not oblique growth.
The Reason is partially correct in stating that prop roots are adventitious roots for extra support,but they are primarily for mechanical support,not assimilation. Therefore,the statement as a whole is considered incorrect in the context of standard botanical definitions where prop roots are strictly for support.

(A) Assertion $(A)$ is correct: Epiphyllous roots (also known as foliar roots) are adventitious roots that develop from the margins of the leaf lamina,as seen in plants like $Bryophyllum$.
Reason $(R)$ is correct: These roots serve as a mechanism for vegetative propagation,allowing the plant to produce new plantlets from the leaf margins when they come in contact with the soil.
Since the formation of these roots is specifically an adaptation for vegetative reproduction,the Reason correctly explains the Assertion.

(D) Monocot roots do not exhibit secondary growth because they lack vascular cambium. Vascular cambium is responsible for secondary growth in dicot roots and stems,which is absent in monocots.

(D) Velamen and spongy tissues are found in the epiphytic roots. These tissues are hygroscopic in nature and help the plant to absorb moisture and water vapor directly from the atmosphere.

(B) Root hairs are tubular extensions of the epidermal cells of the root.
They are unicellular structures that increase the surface area for the absorption of water and minerals from the soil.

(C) In plants,water and minerals are primarily absorbed by the root hairs located in the root hair zone.
This region is also known as the zone of differentiation or maturation.
The cells in this zone undergo maturation and differentiate into various types of primary tissues of the roots,which facilitates the efficient uptake of water and dissolved minerals from the soil.

(D) Plants can absorb water through their entire surface. However,water is primarily found in the soil,and the root system,which is positively geotropic,is specialized for water absorption. Within the root system,the most efficient region for water absorption is the root hair zone,also known as the zone of differentiation.

(C) The zone of cell differentiation (also known as the root hair zone) in roots is primarily responsible for the absorption of water and minerals from the soil.
Root cells in this zone are non-photosynthetic because they lack chlorophyll,meaning they cannot perform photosynthesis.
Since photosynthesis does not occur,these cells do not take up $CO_{2}$ for carbon fixation.
However,these cells do require $O_{2}$ for cellular respiration to generate energy for active transport processes.

(A) $Viscum$ is a hemiparasitic plant that derives water and minerals from the host plant.
It develops specialized structures called $Haustoria$ that penetrate the host tissues to absorb nutrients.

(B) number of mangrove plants possess small,negatively geotropic vertical roots called pneumatophores.
Pneumatophores have lenticels for gaseous exchange.
They are connected with internal aerenchymatous tissue.
It is a plant adaptation to a saline environment.

(B) Mangrove plants grow in saline,waterlogged,and oxygen-deficient soils. To survive in these conditions,they have developed specialized adaptations. They minimize water loss through thick,waxy leaves and facilitate aeration to their underground root systems through specialized roots called pneumatophores (respiratory roots),which grow vertically upwards to absorb oxygen from the atmosphere.

(A) Plants that grow on or are attached to rocks are known as lithophytes.
- Lithophytes derive their nutrients from the surrounding environment,such as rain,air,and decaying organic matter that accumulates in rock crevices.
- Aerophytes are air plants that grow on other plants.
- Halophytes are plants adapted to grow in high-salinity environments.
- Psammophytes are plants that grow in sandy soils.

(N/A) Carrot: Tap root
$(b)$ Colocasia: Stem (Corm)
$(c)$ Sweet potato: Adventitious root
$(d)$ Asparagus: Adventitious root
$(e)$ Radish: Tap root
$(f)$ Potato: Stem (Tuber)
$(g)$ Dahlia: Adventitious root (Fasciculated)
$(h)$ Turmeric: Stem (Rhizome)
$(i)$ Gladiolus: Stem (Corm)
$(j)$ Ginger: Stem (Rhizome)
$(k)$ Portulaca: Adventitious root

(A) In dicotyledonous plants, the direct elongation of the radicle leads to the formation of the primary root which grows inside the soil. It bears lateral roots of several orders that are referred to as secondary, tertiary, etc. roots. The primary roots and their branches constitute the $Tap \text{ root system}$.
In monocotyledonous plants, the primary root is short-lived and is replaced by a large number of roots. These roots originate from the base of the stem and constitute the $Fibrous \text{ root system}$.
Therefore, dicotyledonous plants have a $Tap \text{ root system}$ and monocotyledonous plants have a $Fibrous \text{ root system}$.

(C) In many plants,roots develop from parts of the plant other than the radicle and are called adventitious roots.
- Tap roots develop directly from the radicle.
- Fibrous roots develop from the base of the stem in monocots.
- Adventitious roots can arise from stems,leaves,or other parts of the plant.

(D) The primary functions of the root system are:
$1$. Absorption of water and minerals from the soil ($I$ is correct).
$2$. Providing a proper anchorage to the plant parts ($II$ is correct).
$3$. Storing reserve food material ($III$ is correct).
$4$. Synthesis of plant growth regulators ($IV$ is correct).
All four statements are correct functions of the root system. Therefore,the total number of correct statements is $4$.

(D) The root is primarily the underground part of the plant.
It generally lacks chlorophyll (Achlorophyllous),so it does not perform photosynthesis.
The root develops from the radicle of the seed.
Therefore,all the given options represent the characteristics of the root.
Thus,the correct answer is $D$.

(C) $1$. Mustard ($Brassica$ $campestris$) has a tap root system,which develops from the radicle.
$2$. Grass,Banyan tree ($Ficus$ $benghalensis$),and Monstera possess adventitious roots.
$3$. Adventitious roots are those that arise from parts of the plant other than the radicle (e.g.,stem or leaves).
$4$. Therefore,out of the four plants listed,$3$ plants (Grass,Banyan tree,and Monstera) have adventitious roots.

(A) The image shows a tap root system,which is characteristic of dicotyledonous plants.
In a tap root system,the primary root (radicle) continues to grow and gives rise to lateral roots of several orders.
Among the given options,Mustard (Brassica campestris) is a dicotyledonous plant and possesses a tap root system.
Wheat and grass are monocotyledonous plants,which typically possess a fibrous root system.

(D) The root is covered at the apex by a thimble-like structure called the root cap.
Just above the root cap is the region of meristematic activity,where cells are very small,thin-walled,and with dense protoplasm.
Following this is the region of elongation,where cells undergo rapid elongation and enlargement.
Finally,the region of maturation is located proximal to the elongation region,where cells differentiate and mature.
Therefore,the correct sequence from the root tip to the base is: Root Cap $\rightarrow$ Region of Meristematic Activity $\rightarrow$ Region of Elongation $\rightarrow$ Region of Maturation.

(D) The root is divided into three main regions: the region of meristematic activity,the region of elongation,and the region of maturation.
$1$. The region of meristematic activity is located a few millimeters above the root cap.
$2$. The cells in this region are very small,thin-walled,and have dense protoplasm.
$3$. These cells divide repeatedly to produce new cells for the growth of the root.
Therefore,the correct answer is the region of meristematic activity.

(C) The root system is divided into different zones starting from the tip:
$1$. The root cap protects the tender apex of the root.
$2$. The region of meristematic activity consists of small,thin-walled cells with dense protoplasm that divide repeatedly. These are undifferentiated,actively dividing cells.
$3$. The region of elongation is where cells undergo rapid enlargement and growth.
$4$. The region of maturation contains differentiated cells that have matured into specific tissues.
Therefore,the region containing undifferentiated cells is the region of meristematic activity.

(B) The root hairs are unicellular,tubular extensions of the epidermal cells of the root,which are specifically known as the $Epiblema$ or $Piliferous$ layer.
These hairs are responsible for the absorption of water and minerals from the soil.
Therefore,the correct option is $B$.

(B) The root tip consists of several distinct regions starting from the apex:
$1$. The $Root \ cap$ is the protective covering at the very tip.
$2$. The $Region \ of \ meristematic \ activity$ lies just above the root cap, where cells divide rapidly.
$3$. The $Region \ of \ elongation$ is where cells undergo rapid enlargement and growth.
$4$. The $Region \ of \ maturation$ is the region where cells differentiate and mature, characterized by the presence of root hairs.
In the provided diagram:
- $P$ indicates the region with root hairs, which is the $Region \ of \ maturation$.
- $Q$ indicates the region just above the root cap, which is the $Region \ of \ meristematic \ activity$.
Therefore, $P$ is the region of maturation and $Q$ is the region of meristematic activity.

(A) $P$. Stilt roots are adventitious roots that arise from the lower nodes of the stem to provide support,as seen in maize and sugarcane $(IV)$.
$Q$. Prop roots are aerial roots that grow downwards from branches to provide mechanical support,characteristic of the banyan tree $(II)$.
$R$. Food storage roots are modified to store nutrients,such as in sweet potato $(I)$.
$S$. Respiratory roots (pneumatophores) are found in plants growing in swampy areas,such as Rhizophora $(III)$,to help in gaseous exchange.
Therefore,the correct matching is $(P-IV), (Q-II), (R-I), (S-III)$.

(C) Adventitious roots are those that arise from parts of the plant other than the radicle.
$1$. Carrot: Tap root (modified for storage).
$2$. Turnip: Tap root (modified for storage).
$3$. Sweet potato: Adventitious root (modified for storage).
$4$. Banyan tree: Adventitious root (prop roots).
$5$. Sugarcane: Adventitious root (stilt roots).
$6$. Maize: Adventitious root (stilt roots).
The plants with adventitious roots are Sweet potato,Banyan tree,Sugarcane,and Maize.
Therefore,the total count is $4$.

(D) Roots are typically positively geotropic,meaning they grow towards the direction of gravity.
However,in certain plants like $Rhizophora$ (mangroves) growing in swampy areas,the roots grow vertically upwards out of the ground to obtain oxygen for respiration.
These specialized roots are known as pneumatophores.
Since they grow against the direction of gravity,they are considered negatively geotropic.

(D) The roots of $Carrot$, $Turnip$, and $Sweet \ potato$ are modified for the storage of food. These are tap roots ($Carrot$, $Turnip$) or adventitious roots ($Sweet \ potato$) that store nutrients. In contrast, the roots of $Maize$ are stilt roots, which provide mechanical support to the plant rather than storing food. Therefore, $Maize$ is the odd one out.

(B) The image shows three types of modified tap roots used for food storage:
$1$. Napiform root (e.g.,Turnip)
$2$. Conical root (e.g.,Carrot)
$3$. Fusiform root (e.g.,Radish)
All three are modifications of the tap root system,which develops from the radicle. Therefore,all three are tap roots.

(D) Root hairs are tubular extensions of the epidermal cells of the root and are unicellular in nature.
Stem hairs,also known as trichomes,are epidermal outgrowths on the stem. They are usually multicellular and may be branched or unbranched,and soft or stiff.

(D) The root system is divided into four distinct regions: the root cap,the meristematic region,the region of elongation,and the region of maturation.
$1$. The root cap protects the delicate root tip.
$2$. The meristematic region is responsible for cell division.
$3$. The region of elongation is responsible for the growth of the root in length.
$4$. The region of maturation contains root hairs,which are unicellular extensions of epidermal cells. These root hairs significantly increase the surface area for the absorption of water and minerals from the soil. Therefore,the maximum absorption of water occurs in the region of maturation.

(B) The primary functions of roots include the absorption of water and minerals from the soil,providing proper anchorage to the plant parts,and storing reserve food material. Roots are characterized by the absence of nodes and internodes,which are features specific to stems. Therefore,the statement that roots carry nodes and buds is incorrect.

(D) Epiphytic plants,such as orchids,grow on other plants for support but do not derive nutrients from them. They possess specialized aerial roots known as epiphytic roots. These roots contain a spongy,multi-layered tissue called velamen,which is capable of absorbing moisture and water vapours directly from the atmosphere.

(A) The cell wall of root hairs is composed of two layers: the outer layer is made of pectin, which is sticky and helps in soil particle adhesion, while the inner layer is composed of cellulose, which provides structural strength. Therefore, $Statement-I$ is correct, and $Statement-II$ is incorrect because the inner layer is made of cellulose, not chitin.

$(D)$ Root hairs are unicellular, tubular extensions of the epidermal cells of the root.
They are colorless, delicate, and thin-walled structures.
Root hairs are short-lived and unbranched.
Therefore, $Statement-I$ is correct because root hairs are indeed colorless and delicate.
$Statement-II$ is incorrect because root hairs are short-lived and unbranched, not long-lived and branched.

(B) The structure of a typical root consists of four distinct regions:
$1$. Root cap region.
$2$. Region of meristematic activity.
$3$. Region of elongation.
$4$. Region of maturation (which includes root hairs).

(B) The root tip is divided into three distinct zones: the meristematic zone,the zone of elongation,and the zone of maturation.
$1$. The meristematic zone is responsible for cell division.
$2$. The zone of elongation is responsible for the growth of the root in length.
$3$. The zone of maturation is the region where cells differentiate and mature.
Root hairs are unicellular extensions of epidermal cells (epiblema) found specifically in the zone of maturation. These hairs are responsible for the absorption of water and minerals from the soil.

(C) Root hairs are tubular extensions of the epidermal cells of the root.
The cell wall of a root hair is differentiated into two layers:
$1$. The outer layer is composed of pectin,which is a sticky substance that helps in the adhesion of the root hair to soil particles.
$2$. The inner layer is composed of cellulose,which provides structural strength and rigidity to the root hair.
Since both statements accurately describe the composition of the root hair cell wall layers,both Statement-$I$ and Statement-$II$ are correct.

(D) The correct answer is $D$.
In plants,lateral roots are endogenous in origin,meaning they arise from internal tissues.
Specifically,they originate from the pericycle,which is a layer of cells located just inside the endodermis in the root.
The pericycle cells undergo division to form the root primordium,which eventually pushes through the cortex and epidermis to emerge as a lateral root.

(C) The correct answer is $C$. In angiosperm roots,the vascular bundles are radial,not collateral.
In a radial arrangement,$Xylem$ and $Phloem$ are present in separate bundles along different radii.
In contrast,a collateral arrangement (found in stems) involves $Xylem$ and $Phloem$ being arranged together in a single bundle along the same radius.

(C) Root hairs are unicellular extensions of the epidermal cells (epiblema) found in the region of maturation of the root. They are responsible for the absorption of water and minerals from the soil.