Question

Identify the correct set of statements:

1. The leaflets are modified into pointed hard thorns in Citrus and Bougainvillea
2. Axillary buds form slender and spirally coiled tendrils in cucumber and pumpkin
3. Stem is flattened and fleshy on Opuntia and modified to perform the function of leaves
4. Rhizophora shows vertically upward growing roots that help to get oxygen for respiration
5. 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

Answer 1

The Correct Option is C

Analyzing the provided statements for correctness:

1. Incorrect: In Citrus, thorns are modified branches, not leaflets. In Bougainvillea, thorns arise from other modifications, thus not applicable as leaflets.
2. Correct: Axillary buds in cucumber and pumpkin are indeed modified into slender, spirally coiled tendrils aiding support and climbing.
3. Correct: In Opuntia, the stem is indeed modified to a flattened, fleshy structure known as a cladode, serving photosynthetic functions usually undertaken by leaves.
4. Correct: Rhizophora, a type of mangrove, has pneumatophores, which are specialized roots growing upward to aid in oxygen intake during respiration.
5. Correct: Subaerial stems like runners in grasses and strawberry facilitate vegetative propagation, enabling new plant growth.

Based on the analysis, the correct combination of statements is: (b), (c), (d) and (e) only.

Answer 2

• Thorns, which are woody, straight, and pointed structures, can also develop from axillary buds on stems. Many plants, including Citrus and Bougainvillea, have thorns.
• Stem tendrils, which are slender and spirally coiled, develop from axillary buds and assist plants in climbing. Examples of plants that use stem tendrils include cucumber, pumpkins, and watermelon.
• In arid regions, some plants modify their stems into flattened structures, such as Opuntia. These structures contain chlorophyll and carry out photosynthesis.
• Rhizophora grows in swampy areas, and many of its roots emerge from the ground and grow vertically upward. These roots, known as pneumatophores, aid in respiration by obtaining oxygen.
• Grass and strawberry underground stems spread to new environments, and new plants are formed through vegetative propagation when older parts die.