Question

Which of the following is odd regarding the conversion of auxillary bud into tendril
1. Cucumber
2. Pumpkin
3. Watermelon
4. Bougainvellea

Answer 1

Correct Answer - Option 4 : Bougainvellea

Explanation:

• All organisms show some changes in their morphological structures to adapt to their surrounding environmental conditions. Angiosperms plants also show some changes in their morphology to adjust with their surroundings. 
• Plants show modifications in their vegetative structures like root, stem, leaves, etc. Generally, modifications are not observed in reproductive parts of plants like flowers, seeds, fruit. 
• The stem or its aerial part modify to carry out specialized functions. They develop modifications for this purpose. modified stems are called metamorphosed stems.
• One of such modifications is stem tendrils. Tendrils are thin, wiry, coiled, photosynthetic, leafless coiled structures. These tendrils give additional support to developing plants. Tendrils also have adhesive glands for fixation.
• Tendrils are of two types-  1. If the tendrils develop from apical buds, they are called apical tendrils. Further growth is carried out by the axillary bud. Such a branching pattern is known as a dichotomous pattern.
• Stem tendrils which develop from axillary buds, are slender and spirally coiled and help plants to climb such as in gourds (cucumber, pumpkins, watermelon) and grapevines.
• Axillary buds of stems may also get modified into woody, straight and pointed thorns. Thorns are found in many plants such as Citrus, Bougainvillea.
• Thereby, Bougainvillea is odd regarding the conversion of axillary bud into a tendril, as in Bougainvillea it develops into a thorn.