The Stem — NEET Biology MCQs with Solutions
Free NEET Biology The Stem MCQs with step-by-step solutions (33 questions). Part of Morphology of Flowering Plants. Practise online on Prepizo — no login needed.
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Questions with solutions
Q1 — The Stem · easy · theory
The stem is distinguished from the root by bearing:
A. Root hairs and a root cap
B. Pneumatophores
C. Only a radicle
D. Nodes, internodes, and buds ✓ Correct
Solution: Stems bear nodes, internodes, leaves and buds, and generally grow away from gravity (negatively geotropic).
Q2 — The Stem · easy · theory
An underground stem modified for food storage, as in potato, is a:
A. Corm
B. Bulb
C. Rhizome
D. Tuber ✓ Correct
Solution: The potato is a stem tuber (with "eyes"/axillary buds); ginger is a rhizome, onion a bulb, colocasia a corm.
Q3 — The Stem · medium · theory
The thorns of Citrus and Bougainvillea are modified:
A. Stipules
B. Roots
C. Leaves
D. Axillary buds (stems) ✓ Correct
Solution: Stem thorns arise in the axil and protect the plant; tendrils of grapevine are also stem modifications.
Q4 — The Stem · medium · theory
A stem tendril helps a weak plant in climbing and arises from the:
A. Axillary bud ✓ Correct
B. Petiole only
C. Leaf apex only
D. Root
Solution: Stem tendrils (e.g. grapevine, cucumber) are modified axillary buds for climbing.
Q5 — The Stem · hard · theory
The phylloclade of Opuntia is a modified stem that is green and flattened to perform photosynthesis because:
A. It stores no water
B. Leaves are reduced to spines to check water loss ✓ Correct
C. Roots are absent
D. It is actually a modified leaf
Solution: In xerophytes like Opuntia, the flattened green stem (phylloclade) photosynthesises while leaves become water-saving spines.
Q6 — The Stem · hard · theory
Runner, stolon, offset and sucker are sub-aerial stem modifications for:
A. Storage of water
B. Support only
C. Vegetative propagation ✓ Correct
D. Respiration
Solution: These sub-aerial stems (e.g. grass runner, mint stolon, water hyacinth offset, chrysanthemum sucker) spread and propagate the plant.
Q7 — The Stem · easy · numerical
Ginger and turmeric are underground horizontal stems that store food and bear nodes, internodes, scale leaves and axillary buds. This modification is a:
A. Rhizome ✓ Correct
B. Corm
C. Bulb
D. Tuber
Solution: Ginger and turmeric are rhizomes — horizontal underground stems with distinct nodes, internodes and scale leaves. A corm is vertical and rounded; a tuber (potato) lacks scale leaves at each node.
Q8 — The Stem · easy · numerical
A grape vine climbs a support using slender, coiled, thread-like structures that arise from axillary buds. These stem tendrils help the plant in:
A. Food storage
B. Vegetative propagation
C. Climbing ✓ Correct
D. Protection
Solution: Stem tendrils, as in grapevine and cucumber, develop from axillary buds and coil around supports, enabling weak-stemmed plants to climb.
Q9 — The Stem · easy · numerical
The "eyes" of a potato that sprout into new shoots are structurally equivalent to:
A. Aerial flower buds that failed to open
B. Nodes bearing axillary buds subtended by scale leaves ✓ Correct
C. Root hairs modified for storage
D. Adventitious roots emerging from internodes
Solution: The potato is a stem tuber; each "eye" is a node with an axillary bud in the axil of a scale leaf. These buds prove the tuber is a stem, not a root.
Q10 — The Stem · medium · numerical
Match the sub-aerial stem with its plant: (i) Runner (ii) Sucker (iii) Offset (iv) Stolon — with (p) Chrysanthemum/mint (q) grass/Oxalis (r) aquatic Eichhornia/Pistia (s) jasmine, arising as a slender lateral branch that arches and roots. The correct match is:
A. (i)-p, (ii)-q, (iii)-r, (iv)-s
B. (i)-q, (ii)-r, (iii)-p, (iv)-s
C. (i)-r, (ii)-p, (iii)-q, (iv)-s
D. (i)-q, (ii)-p, (iii)-r, (iv)-s ✓ Correct
Solution: Runners creep along the ground in grasses/Oxalis (q); suckers grow up from underground bases in Chrysanthemum/mint (p); offsets are found in aquatic Eichhornia/Pistia (r); stolons arch out and root as in jasmine (s).
Q11 — The Stem · medium · numerical
Which pair of stem modifications is correctly grouped as both being protective (defensive) modifications?
A. Tendril of passion flower and thorn of Bougainvillea
B. Phylloclade of Opuntia and tuber of potato
C. Rhizome of ginger and corm of Colocasia
D. Thorns of Duranta and thorns of Citrus ✓ Correct
Solution: Thorns are woody, pointed axillary-bud modifications for protection; both Duranta and Citrus bear stem thorns. Tendrils are for climbing and phylloclades/rhizomes are for photosynthesis/storage.
Q12 — The Stem · medium · numerical
In xerophytes like Opuntia the stem becomes green, flattened and fleshy while the leaves are reduced to spines. This flattened photosynthetic stem of unlimited growth is termed a:
A. Phylloclade ✓ Correct
B. Phyllode
C. Bulbil
D. Cladode
Solution: A phylloclade is a flattened or cylindrical green stem of indefinite growth taking over photosynthesis (Opuntia). A cladode is a similar but short, one-or-two-internode green stem (Asparagus); a phyllode is a modified petiole.
Q13 — The Stem · easy · theory
Which is correctly matched?
A. Onion – Bulb ✓ Correct
B. Chlamydomonas – Conidia
C. Ginger – Sucker
D. Yeast – Zoospores
Solution: Onion is a bulb (condensed underground stem); ginger is a rhizome, Chlamydomonas reproduces by zoospores, and yeast by budding.
Q14 — The Stem · easy · theory
Rhizome of ginger is a modification of stem because -
A. It stores food material
B. It bears adventitious roots
C. It bears nodes and internodes ✓ Correct
D. It is underground
Solution: Presence of nodes, internodes and scale leaves with axillary buds identifies the rhizome as a stem, not a root.
Q15 — The Stem · easy · theory
Thorns and spines are -
A. Storage organs
B. Respiratory organs
C. Defensive organs ✓ Correct
D. Both defensive and respiratory organs
Solution: Thorns and spines are protective/defensive structures that guard the plant against grazing.
Q16 — The Stem · easy · theory
In onion the swollen underground structure is -
A. Tuber
B. Bulb ✓ Correct
C. Rhizome
D. Root
Solution: Onion is a bulb, a condensed underground stem with fleshy scale leaves.
Q17 — The Stem · medium · theory
Vegetative propagation in mint occurs by :-
A. Sucker ✓ Correct
B. Offset
C. Runner
D. Rhizome
Solution: Mint spreads vegetatively through suckers, lateral branches arising from the underground stem base.
Q18 — The Stem · medium · theory
Vegetative propagation in Pistia occurs by :
A. Stolon
B. Runner
C. Sucker
D. Offset ✓ Correct
Solution: The aquatic Pistia propagates by offsets, short runners bearing a rosette of leaves.
Q19 — The Stem · easy · theory
Which one of the following is a xerophytic plant in which the stem is modified into a flat, green and succulent structure?
A. Casuarina
B. Acacia
C. Opuntia ✓ Correct
D. Hydrilla
Solution: In Opuntia the stem becomes a flat, green, fleshy phylloclade that performs photosynthesis.
Q20 — The Stem · easy · theory
The "eyes" of the potato tuber are :-
A. Flower buds
B. Root buds
C. Axillary buds ✓ Correct
D. Adventitious roots
Solution: The eyes of a potato are axillary buds seated at the nodes, confirming it is a stem tuber.
Q21 — The Stem · easy · theory
An example of edible underground stem is :
A. Carrot
B. Sweet potato
C. Groundnut
D. Potato ✓ Correct
Solution: Potato is a stem tuber, an edible underground stem; carrot and sweet potato are roots.
Q22 — The Stem · easy · theory
Which of the following is not a stem modification?
A. Thorns of Citrus
B. Flattened structures of Opuntia
C. Pitcher of Nepenthes ✓ Correct
D. Tendrils of cucumber
Solution: The pitcher of Nepenthes is a modified leaf; the others are all stem modifications.
Q23 — The Stem · easy · theory
Stems modified into flat green organs performing the functions of leaves are known as :-
A. Scales
B. Phylloclades ✓ Correct
C. Cladodes
D. Phyllodes
Solution: Flattened green photosynthetic stems are called phylloclades (e.g., Opuntia).
Q24 — The Stem · easy · theory
Function of stem is to :-
A. Bear leaves/branches, conduct water, minerals and food, and store food ✓ Correct
B. Only bear leaves and branches
C. Only conduct water and minerals
D. Only store food
Solution: The stem bears leaves/branches, conducts water, minerals and food, and can store food.
Q25 — The Stem · medium · theory
Assertion (A): Generally, dicotyledonous plants have tap roots and reticulate venation while monocotyledonous plants have fibrous roots and parallel venation. Reason (R): Morphological features of the stem such as nodes and internodes, multicellular hairs and positively phototropic nature help to differentiate the stem from roots.
A. Both assertion and reason are true, but reason is not the correct explanation of assertion ✓ Correct
B. Both assertion and reason are false
C. Assertion is true, but reason is false
D. Both assertion and reason are true and reason is the correct explanation of assertion
Solution: Both statements are individually true, but the stem features do not explain the root/venation differences between dicots and monocots.
Q26 — The Stem · hard · theory
Statement I: Opuntia and Euphorbia found in arid regions contain chlorophyll in their roots and carry out photosynthesis. Statement II: Stem tendrils found in gourds and grapevines are slender, spirally coiled and help plants to protect themselves from grazers.
A. Both statements I and II are correct
B. Only statement I is correct
C. Both statements I and II are incorrect ✓ Correct
D. Only statement II is correct
Solution: In Opuntia/Euphorbia the flattened green STEM (not root) does photosynthesis, and stem tendrils help in climbing, not protection from grazers.
Q27 — The Stem · medium · theory
Green leaf-like stem branches of one internode length are called
A. Phylloclades
B. Cladodes ✓ Correct
C. Bulbils
D. Phyllodes
Solution: A cladode is a green, flattened stem branch of one internode length; a phylloclade has many internodes.
Q28 — The Stem · hard · theory
Match the columns and select the correct combination. a. Underground stem, b. Stem tendril, c. Stem thorn, d. Flattened stem, e. Fleshy cylindrical stem; p. Euphorbia, q. Opuntia, r. Potato, s. Citrus, t. Cucumber
A. a-r, b-t, c-s, d-q, e-p ✓ Correct
B. a-q, b-r, c-s, d-t, e-p
C. a-r, b-s, c-t, d-p, e-q
D. a-p, b-q, c-r, d-t, e-s
Solution: Potato=underground stem, Cucumber=stem tendril, Citrus=stem thorn, Opuntia=flattened stem, Euphorbia=fleshy cylindrical stem.
Q29 — The Stem · hard · theory
How many plants among Canna, Oxalis, Eichhornia, Ginger, Garlic, Lemon, Wheat, Gladiolus and Saffron have underground modified stems?
A. Four
B. Three
C. Six
D. Five ✓ Correct
Solution: Canna (rhizome), Ginger (rhizome), Garlic (bulb), Gladiolus (corm) and Saffron (corm) are underground stem modifications = five.
Q30 — The Stem · medium · theory
In ginger, vegetative propagation occurs through the
A. Offsets
B. Runners
C. Bulbils
D. Rhizome ✓ Correct
Solution: Ginger propagates vegetatively by its underground stem, the rhizome.