Stem Types and Modifications Practice Questions
20 free Stem Types and Modifications practice questions for the NCERT Biology. Tap an option to answer — you get instant feedback, the correct answer, and a detailed explanation for every question.
The stem develops from which part of the embryo of a germinating seed?
- A Radicle, which gives rise to the root
- B Plumule, which gives rise to the shoot
- C Cotyledon, which stores seed nutrients
- D Endosperm, which nourishes the embryo
Correct answer: Plumule, which gives rise to the shoot
The stem is the ascending part of the plant axis that develops from the plumule of the embryo. In contrast, the root system develops from the radicle.
The regions of the stem where leaves are borne are called ______ while the portions between them are called ______.
- A Nodes, Internodes
- B Internodes, Nodes
- C Buds, Axils
- D Axils, Buds
Correct answer: Nodes, Internodes
Nodes are the specific points on the stem where leaves are attached. The spaces or segments of the stem between two successive nodes are referred to as internodes.
Which of the following is an example of an underground stem modified for food storage?
- A Carrot (modified tap root)
- B Sweet potato (modified adventitious root)
- C Potato (modified stem tuber)
- D Radish (modified tap root)
Correct answer: Potato (modified stem tuber)
Potato is a modified underground stem (tuber) used for storing food and perennation. Carrot, sweet potato, and radish are all modified roots.
Slender and spirally coiled structures that develop from axillary buds and help plants climb are called:
- A Leaf thorns
- B Stem tendrils
- C Phylloclades
- D Stem bulbils
Correct answer: Stem tendrils
Stem tendrils are slender, spirally coiled modifications of axillary buds found in plants like gourds (cucumber, pumpkin, watermelon) and grapevines. They coil around external supports to help the plant climb.
Thorns, which are woody, straight, and pointed modifications of axillary buds, are found in which of the following plants?
- A Opuntia and Euphorbia
- B Citrus and Bougainvillea
- C Cucumber and Watermelon
- D Strawberry and Jasmine
Correct answer: Citrus and Bougainvillea
In plants like Citrus and Bougainvillea, axillary buds lose their ability to grow into branches and instead become woody, pointed thorns. These thorns protect the plant from browsing animals.
In arid regions, some plants modify their stems into flattened or fleshy cylindrical structures containing chlorophyll to perform photosynthesis. These are called:
- A Leaf phyllodes
- B Stem cladodes
- C Phylloclades
- D Stem thorns
Correct answer: Phylloclades
Phylloclades are stem modifications found in xerophytic plants like Opuntia (flattened) and Euphorbia (cylindrical). They contain chlorophyll and take over the function of leaves, which are often reduced to spines to conserve water.
Underground stems of some plants like _______ spread to new niches and when older parts die, new plants are formed.
- A Potato and Ginger
- B Grass and Strawberry
- C Citrus and Bougainvillea
- D Banana and Pineapple
Correct answer: Grass and Strawberry
Grasses and strawberry possess underground stems that spread to new areas (runners). This serves as a method of vegetative propagation where the death of the parent allows the new niche colonization to continue.
A slender lateral branch arises from the base of the main axis and after growing aerially for some time, arches downwards to touch the ground in:
- A Mint and Jasmine plants
- B Pistia and Eichhornia
- C Grass and Strawberry
- D Banana and Pineapple
Correct answer: Mint and Jasmine plants
This growth pattern describes a stolon. In plants like mint and jasmine, a slender lateral branch arises from the base of the main axis, grows aerially for a period, and then arches downward to touch the ground, where it roots and produces a new daughter plant.
In aquatic plants like Pistia and Eichhornia, a lateral branch with short internodes and each node bearing a rosette of leaves and a tuft of roots is called a/an:
- A Runner
- B Sucker
- C Stolon
- D Offset
Correct answer: Offset
An offset is a short, thick lateral branch commonly found in aquatic rosette plants. It facilitates rapid vegetative propagation across the water surface.
Which of the following plants propagate through suckers, where lateral branches originate from the underground portion of the main stem and come out obliquely upward?
- A Mint and Jasmine
- B Banana and Chrysanthemum
- C Opuntia and Euphorbia
- D Pistia and Eichhornia
Correct answer: Banana and Chrysanthemum
Suckers are lateral branches that grow horizontally under the soil before emerging obliquely upward to give rise to leafy shoots. This mode of propagation is seen in banana, pineapple, and chrysanthemum.
Which of the following is NOT a function of the stem?
- A Spreading out branches bearing leaves, flowers, and fruits
- B Conduction of water, minerals, and photosynthates
- C Absorption of water and minerals from the soil
- D Storage of food and vegetative propagation
Correct answer: Absorption of water and minerals from the soil
Absorption of water and minerals is the primary function of the root system. The stem is responsible for conduction, support, and sometimes storage or protection.
Zaminkand and Colocasia are examples of underground stems modified for:
- A Providing climbing supports
- B Performing photosynthesis
- C Perennation and storage
- D Protection from grazers
Correct answer: Perennation and storage
The corms of Zaminkand and Colocasia are underground stems modified to store food and nutrients. They also serve as organs of perennation, enabling the plant to survive unfavorable growing conditions.
Which part of the Opuntia plant is modified to perform the function of leaves?
- A Root
- B Stem
- C Flower
- D Bud
Correct answer: Stem
In Opuntia, the stem becomes flattened, green, and fleshy (phylloclade). It contains chlorophyll and carries out photosynthesis because the leaves are modified into spines.
Stem tendrils in gourds are homologous to _______ in Citrus.
- A Leaves
- B Roots
- C Thorns
- D Flowers
Correct answer: Thorns
Both stem tendrils in gourds and thorns in Citrus are modifications of the axillary bud. Because they share the same embryonic origin, they are considered homologous structures.
A student identifies an underground stem that grows horizontally and has distinct nodes and internodes. This structure is a:
- A Stem tuber
- B Scaly bulb
- C Rhizome
- D Solid corm
Correct answer: Rhizome
A rhizome, such as in ginger or turmeric, is an underground stem that grows horizontally. It is distinguished from roots by the presence of nodes, internodes, and scale leaves.
The fleshy cylindrical stem modification seen in Euphorbia is technically a:
- A Stem cladode
- B Leaf phyllode
- C Phylloclade
- D Stem thorn
Correct answer: Phylloclade
Euphorbia possesses a fleshy cylindrical phylloclade. Like the flattened phylloclade of Opuntia, it is a stem modification that enables photosynthesis and water storage in arid climates.
In which plant does the lateral branch grow aerially for a period before arching down to the soil?
- A Fragaria
- B Chrysanthemum
- C Jasmine
- D Eichhornia
Correct answer: Jasmine
Jasmine (and mint) produce stolons. These lateral branches grow into the air initially but eventually bend back to the ground to root and form new plants.
Which of the following represents the correct set of plants with underground stem modifications for food storage?
- A Potato, Ginger, and Turmeric
- B Ginger, Apple, Mango, and Potato
- C Colocasia, Radish, Beetroot, and Ginger
- D Potato, Carrot, Sweet Potato, and Turnip
Correct answer: Potato, Ginger, and Turmeric
Potato, ginger, and turmeric are classic examples of underground stems modified for food storage. The other options incorrectly include true roots such as carrot, radish, and turnip, which are root modifications, not stem modifications.
Identify the modification where the stem is reduced and leaves become fleshy for food storage.
- A Food tuber
- B Scaly bulb
- C Solid corm
- D Rhizome
Correct answer: Scaly bulb
In a bulb (like onion or garlic), the stem is highly reduced to a disc-like structure. The storage function is performed by the fleshy scale leaves attached to this reduced stem.
Axillary buds are located at the:
- A Tip of the stem
- B Base of the root
- C Axil of the leaves
- D Center of the internode
Correct answer: Axil of the leaves
Axillary buds are found in the axil—the angle between the upper side of a leaf and the stem. They have the potential to form branches or flowers.