Question

Which among the following sets has homologous organs?
A) Hands of man, monkey and kangaroo and trunk of elephant
B) Hind limbs of grasshopper, horse and bat
C) Both A and B
D) Mouth parts of cockroach, mosquitos and honey bees.

Answer 1

Hint:Homologous organs are the organs of closely related organisms with similar basic structure and same origin but may perform different functions. These organs are formed as a result of divergent evolution or adaptive radiation.

Complete answer:
During evolution of organisms, different types of descendants may evolve from a common ancestor. This phenomenon is called divergent evolution. Homologous organs have the same origin as in the stage of embryonic development, the development patterns will be similar. Note that they will have different external forms in most cases as they will not look similar in external appearance. Examples of homologous organs are the forelimbs of mammals. We can see that the forelimbs of animals like whales, bats, cheetah, humans etc have the same basic structure but different functions.

Another example for homologous organs are mouthparts of cockroaches, mosquitoes and honey bees. They are closely related organisms as they all belong to the same phylum Arthropoda. Mouth parts of these organisms have the same basic structure but widely differ in their functions.Thorn of bougainvillea and tendril of cucurbita are also considered as homologous in nature.

Hence the correct answer is option ‘D’.

Note:Organs that have the same functions but have different origin and structure are called analogous organs. Know that these are the result of convergent evolution. Examples for convergent evolution are wings of butterfly and bird, sweet potato and potato for food storage etc. Know that evolution of different groups of organisms in the same direction by acquiring same adaptations and morphological features is called convergent evolution.