Question

Thorn of Bougainvillea and tendril of Cucurbita are example of?

• A. Vestigial organ
• B. Homologous organ
• C. Analogous organ
• D. Retrogressive organ

Answer 1

The correct option is B

Homologous organ

The correct option is B.

The explanation of the correct option:

1. Homologous organs are defined as organs that originate from the same origin but perform different tasks.
2. Examples of homologous organs include the thorns of bougainvillea and the tendrils of cucumbers.
3. Cucurbita tendrils and Bougainvillea thorns are both modified axillary buds, their functions are different from one another.
4. The thorn serves as a defense against grazing animals. The tendrils aid in providing support when climbing. They are anatomically similar but vary in function. As a result, they are homologous.

The explanation of incorrect options:

Option (A):

1. Vestigial organs are organs that are present but of no use.
2. Cucurbita tendrils and Bougainvillea thorns both are useful as Cucurbita tendrils help in climbing whereas Bougainvillea thorns prevent wild animals.
3. Hence, it is an incorrect option.

Option (C):

1. Analogous organs are defined as structures that have different origins but perform the same function.
2. Cucurbita tendrils and Bougainvillea thorns have same origin i.e. Axillary buds.
3. Hence, it is an incorrect option.

Option (D):

1. Organs that are lost after development are called retrogressive organs.
2. Cucurbita tendrils and Bougainvillea thorns are not retrogressive organs as they persist throughout the plant life.
3. Hence, it is an incorrect option.

Final answer: Therefore, the thorn of Bougainvillea and tendril of Cucurbita are examples of homologous organs.