Stem Questions in English

(B) In plants like gourds (cucumber,pumpkins,watermelons),the axillary buds are modified into slender,spirally coiled,sensitive structures known as tendrils. These structures help the plant in climbing.

(D) In $Bougainvillea$,the axillary buds are modified into woody,straight,and pointed structures known as thorns. These thorns provide protection to the plant against browsing or grazing animals.

(B) In $Opuntia$,the stems are modified into flattened,green,succulent structures known as phylloclades,which perform photosynthesis to compensate for the reduction of leaves into spines.

(D) In $Euphorbia$,the stem is modified into a green,fleshy,cylindrical,or flattened structure known as a $Phylloclade$.
This modification allows the plant to perform photosynthesis and store water,which is an adaptation to arid environments.

(B) Phylloclade is a stem modification where the stem becomes green,flattened,and fleshy,capable of unlimited growth to perform photosynthesis (assimilatory function). Examples include $Opuntia$ and $Euphorbia$.

(B) The $Tuber$ of potato is a modified underground stem.
The $Corm$ of Colocasia is a modified underground stem.
The $Rhizome$ of ginger is a modified underground stem.
The $Pitcher$ of $Nepenthes$ is a modification of the leaf,where the leaf lamina is modified into a pitcher-like structure to trap insects.

(C) $Pineapple$ reproduces vegetatively through a modified stem structure known as a $Sucker$.
These suckers grow laterally beneath the soil surface and eventually emerge to form new independent plants,thus aiding in vegetative propagation.
$Vanda$ is an epiphyte with hanging roots that absorb moisture from the atmosphere,not tap roots.
$Jasmine$ propagates via $Stolons$,not offsets.
$Nepenthes$ (Pitcher plant) uses its leaf tip to form a pitcher for trapping insects,not primarily for photosynthesis.

(C) The Assertion is correct because a corm is a condensed form of a rhizome that grows vertically beneath the soil surface.
The Reason is incorrect because a corm typically bears nodes,internodes,buds,and scaly leaves,not green leaves. Green leaves are usually found on the aerial part of the plant,whereas the corm is an underground stem modification.

(B) Epiphytes are plants that grow on other plants for physical support but do not derive any nutrients or water from them. They are not parasitic. Examples include orchids,mosses,and certain ferns.

(B) corm is a short,vertical,swollen,underground plant stem that serves as a storage organ used by some plants to survive winter or other adverse conditions.
It is unbranched and rounded in shape.
Examples of plants that reproduce via corms include Colocasia (also known as taro) and Gladiolus.
In contrast,Ginger is a rhizome,Onion is a bulb,and Potato is a tuber.

(C) corm is a short,vertical,swollen underground plant stem that serves as a storage organ used by some plants to survive winter or other adverse conditions.
It is a modified stem because it possesses nodes and internodes,and it bears scale leaves and axillary buds,which are characteristic features of a stem.
Examples of plants that reproduce via corms include $Colocasia$ and $Amorphophallus$.

(B) The potato tuber is a modified underground stem. The 'eyes' of the potato represent the nodes of the stem. Each eye contains a small scale leaf with an axillary bud. Because these buds arise from the nodes and are capable of developing into new shoots,they are classified as nodal buds. Additionally,since they arise from a location other than the normal terminal position,they are also referred to as adventitious buds in some contexts,but specifically,they are axillary buds located at the nodes. Given the options,the correct classification for the buds on a potato tuber is nodal and axillary bud.

(B) In $Opuntia$,the leaves are modified into spines to reduce water loss through transpiration as an evolutionary adaptation.
Consequently,the stem takes over the function of photosynthesis.
The stem of $Opuntia$ is green,fleshy,and flattened (phylloclade),which allows it to perform photosynthesis efficiently.

(A) $\rightarrow$ In ginger,the edible part is a modified stem known as a rhizome,which stores food.
$\rightarrow$ In onion,the edible part consists of fleshy,succulent leaves that store food. The stem is reduced to a disc-like structure,and the leaves are arranged in a concentric manner.

(B) The $stem$ is the ascending part of the axis bearing branches,leaves,flowers,and fruits.
It develops from the plumule of the embryo of a germinating seed.
The $stem$ is characterized by the presence of nodes and internodes.
Nodes are the regions of the $stem$ where leaves are born,while internodes are the portions between two nodes.

(A) In a developing seed,the embryo consists of a radicle and a plumule.
$1$. The $Radicle$ is the embryonic root that develops into the root system.
$2$. The $Plumule$ is the embryonic shoot that develops into the stem and leaves of the plant.
$3$. Therefore,the stem develops from the $Plumule$.

(C) The stem is the ascending part of the axis bearing branches,leaves,flowers,and fruits. The stem bears nodes and internodes. The region of the stem where leaves are born is called nodes,while internodes are the portions between two nodes. Therefore,leaves originate from the nodes of the stem.

(B) The image shows ginger (rhizome),Colocasia (corm),and potato (tuber). These are all modified stems that have evolved to store food materials. While they can also perform vegetative propagation,their primary and most characteristic function as modified stems in this context is the storage of food.

(C) potato is a modified underground stem known as a tuber.
It is classified as a stem because it exhibits characteristic stem features such as the presence of nodes and internodes.
The 'eyes' of the potato are actually axillary buds,and it also possesses terminal buds,which are characteristic features of a stem.
While it stores food and grows underground,these features are secondary to the presence of buds,which confirms its identity as a stem.

(D) In many plants,the young stem is green and contains chlorophyll,allowing it to perform photosynthesis. Additionally,in xerophytic plants like $Opuntia$ (prickly pear),the stem becomes flattened and fleshy,taking over the function of photosynthesis because the leaves are modified into spines to reduce water loss. Therefore,both young stems and the stems of $Opuntia$ perform photosynthesis.

(C) Stem tendrils are slender,spirally coiled structures that help plants in climbing. They develop from the axillary buds of the stem. Examples include plants like gourds (cucumber,pumpkins,watermelons) and grapevines. Therefore,the correct option is $C$.

(B) In plants like $Pistia$ and $Eichhornia$ (water hyacinth),the stem is modified into an offset.
These plants grow in aquatic environments.
The stem is short,and each node bears a rosette of leaves and a tuft of roots,which helps in vegetative propagation.

(D) The image shows a plant with tendrils. Tendrils are slender,spirally coiled structures that help plants in climbing. In plants like cucumbers,pumpkins,and watermelons (members of the Cucurbitaceae family),the axillary buds develop into tendrils. Therefore,the correct option is $D$ (Cucumber).

(B) The stem of a plant is generally green when it is young because it contains chlorophyll and performs photosynthesis.
As the plant matures and grows older,the stem undergoes secondary growth,develops bark,and turns brown in color due to the deposition of lignin and other substances.

(A) In $Opuntia$ (prickly pear cactus),the leaves are modified into spines to reduce water loss through transpiration and provide protection against herbivores. The stem becomes flattened,fleshy,and green to perform photosynthesis,as it takes over the function of the leaves in arid environments.

(B) rhizome is a modified underground stem that grows horizontally (prostrate) beneath the soil surface.
It is characterized by being thick,fleshy,and branched.
It possesses distinct nodes and internodes,where nodes often bear scale leaves and axillary buds.
The apical bud of a rhizome typically remains underground to facilitate continuous horizontal growth,not above the ground.
Therefore,the statement that the apical bud remains above the ground is incorrect.