Stem and leaf, and how each is modified — practice questions

Question 1 · difficulty L1 · recall

Which underground stem modification is found in potato?

• A. Tuber
• B. Rhizome
• C. Corm
• D. Bulb

Question 2 · difficulty L2 · understanding

How can a potato tuber be recognised as a stem rather than a root?

• A. It bears nodes and buds called eyes
• B. It absorbs water from the soil
• C. It stores starch
• D. It grows below ground

Question 3 · difficulty L3 · understanding

Bulliform cells are responsible for

• A. Inward curling of leaves in monocots.
• B. Protecting the plant from salt stress.
• C. Increased photosynthesis in monocots.
• D. Providing large spaces for storage of sugars.

Question 4 · difficulty L3 · understanding

Which of the following statement is not correct?

• A. The rhizome is thick, prostrate and branched
• B. Rhizome is a condensed form of stem
• C. The apical bud in rhizome always remains above the ground
• D. The rhizome is aerial with no distinct nodes and internodes

Question 5 · difficulty L3 · understanding

Identify the correct set of statements: (a) The leaflets are modified into pointed hard thorns in Citrus and Bougainvillea (b) Axillary buds form slender and spirally coiled tendrils in cucumber and pumpkin (c) Stem is flattened and fleshy in Opuntia and modified to perform the function of leaves (d) Rhizophora shows vertically upward growing roots that help to get oxygen for respiration (e) Subaerially growing stems in grasses and strawberry help in vegetative propagation Choose the correct answer from the options given below:

• A. (b) and (c) only
• B. (a) and (d) only
• C. (b), (c), (d) and (e) only
• D. (a), (b), (d) and (e) only

Question 6 · difficulty L3 · application

A climbing plant bears a slender coiled structure arising from an axillary bud and used for support. Which organ has been modified?

• A. Stem
• B. Root
• C. Leaflet
• D. Stipule

Question 7 · difficulty L3 · application

In a desert plant, leaves are reduced to spines while a green flattened stem performs photosynthesis. What is the main adaptive advantage of this arrangement?

• A. Reduced water loss while maintaining photosynthesis
• B. Increased transpiration and cooling
• C. Greater dependence on leaf stomata
• D. Elimination of the need for chlorophyll

Question 8 · difficulty L4 · analysis

Organ X is green, flattened, bears nodes and performs photosynthesis; organ Y is a leaf modified into a spine. Which observation most strongly supports the conclusion that X is a stem?

• A. Presence of nodes and axillary buds
• B. Green colour
• C. Exposure to sunlight
• D. Ability to photosynthesise