Question

A. Differentiate between analogous and homologous structures.
B. Select and write analogous structures from the list given:
 (i) Wings of butterfly and birds
 (ii) Vertebrate hearts
 (iii) Tendrils of bougainvillea and Cucurbita
 (iv) Tubers of sweet potato and potato.

Answer 1

Hint: Study of similarities and differences in the anatomy such as the body structure of two or more than two species is called comparative anatomy.

Complete answer:

Analogous Structure	Homologous Structure
They show superficial resemblance morphology	These have similar morphology.
They show similar functions.	They differ in functions.
Analogous organs show convergent evolution.	Homologous organs show divergent evolution.
These organs do not share similar ancestors	These organs show common ancestors.
Examples like- Wings of birds, insects, etc.	Examples like- Forelimbs of bats, whales, etc.

(b) (i) Wings of butterflies and wings of birds are an example of the analogous structure as they both are similar in function i.e. used for flying but they differ in origin and structural details. Wings of birds are originated from forelimbs while the wings of a butterfly are extensions of the integument.
 (iv) Tubers of sweet potato and potato are an example of the analogous organs or structures. They both have similar functions that are the storage of food in the form of starch. They differ in structural origin because sweet potato is a root tuber while potatoes are stem tuber.
While part (ii) Vertebrate hearts and (ii) Tendrils of bougainvillea and Cucurbita both are examples of homologous organs or structures because they share similar structures but differ in function.
Note: The comparative study in biology is important to understand the areas of variations that gave rise to evolution. Evolution in organisms occurs for helping them to survive in the environment.