Question

Homologous organs are
A. Dissimilar origin and dissimilar structure.
B. Dissimilar origin but similar functions
C. Similar origin with similar or dissimilar functions
D. Similar origin with dissimilar functions

Answer 1

Hint: Homologous organs are unique organs and have an alternate aim, perform different functions, and have the same origin. Example- arms of humans. That means they may have similar origins but have dissimilar functions.

Complete answer:
Homologous structures are organs or skeletal elements of animals and organisms. These organs show similarity in their connection to a common ancestor by virtue. Though, these structures do not look exactly the same or perform the same function. The most important character as hinted by their name is that they are structurally similar.

Examples of Homologous Structures
The arm of a human, the leg of a dog, the wing of a bird or a bat, and the flipper of a dolphin or whale. These are homologous organs because they are different and have a different purpose, but they are similar and share common traits.

> Option A- Dissimilar origin and dissimilar structure
This is not correct because homologous organs have similar origin.

> Option B- Dissimilar origin but similar functions
This option is wrong because homologous organs have similar origin with dissimilar functions.

> Option C- Similar origin with similar or dissimilar functions
This is incorrect because homologous organs surely have dissimilar functions. They never have similar functions.

> Option D- Similar origin with dissimilar functions
This is the correct option because homologous organs have similar origins with dissimilar functions.

Hence, the correct answer is option (D).

Note: Homologous organs exhibit the same structural plan whereas analogous organs exhibit different structures in different animals. Homologous organs perform different functions and analogous organs always perform the same functions.