Question

Which one of the following are analogous structures?

• A. Gills of prawn and lungs of man
• B. Thorns of Bougainvillea and tendrils of Cucurbita
• C. Flippers of dolphin and legs of horse
• D. Wings of bat and wings of pigeon

Answer 1

The Correct Option is A

To understand which option represents analogous structures, we must first define what analogous structures are. In biology, analogous structures are those that perform similar functions but have evolved separately and do not share a common ancestor. These structures arise due to convergent evolution, where species of different lineages come to resemble each other because they have adapted to similar environments or ecological niches.

1. Option 1 - Gills of prawn and lungs of man:

   Both gills and lungs are organs used for breathing, although they function in different environments. Gills are used for extracting oxygen from water, while lungs are used for air. Despite serving a similar function, these structures evolved differently in invertebrates and vertebrates. Hence, they are analogous structures.

2. Option 2 - Thorns of Bougainvillea and tendrils of Cucurbita:

   Thorns and tendrils, although serving different functions, are modifications of branches or leaves. These structures arise from the same developmental pathways but are adapted differently. Therefore, they are an example of homologous structures, not analogous.

3. Option 3 - Flippers of dolphin and legs of horse:

   Flippers and legs have different functions (swimming vs. running), but they have evolved from a common limb structure in mammals. Therefore, they are homologous structures, not analogous.

4. Option 4 - Wings of bat and wings of pigeon:

   While both are used for flying, bat wings and pigeon wings are different structurally; one has evolved from mammalian forelimbs, while the other evolved in birds. However, they are still considered homologous because they share a common ancestral root feature. Thus, they are not analogous structures.

The correct answer is Gills of prawn and lungs of man as they perform similar functions but have arisen through different evolutionary paths, classifying them as analogous structures.