Question

Describe the differences between Homologous and heterologous organs with suitable examples.

Answer 1

Hint: When a gene is expressed in diverse species types or cell types from which it originated, then such type of expression is called heterogeneous expressions, while genes expressed in the same species type are called homologous expressions.

Complete Answer:

Sl.No	Homologous organs	Heterologous organs
1.	The morphological characters vary.	The morphological character shows similarities.
2.	Internal structures are found to be identical.	Internal structures are found to be dissimilar.
3.	They are developed in associated organisms.	They are developed in unassociated organisms.
4.	Similarities are found in the various phases of development.	Differences are found in the different phases of development.
5.	They execute diverse functions.	They exhibit the same functions.
6.	The developmental pattern is similar in them.	The developmental pattern is different.
7.	These organs demonstrate adaptive radiation.	These organs exhibit convergent evolution.

Moreover, identical traits could be either homologous or heterologous. The homologous organs share alike embryonic sources, while heterologous organs have similar functions. For instance, the bones found in the front flipper sections of whales are found to be identical with the bones present in the human arm. These arrangements do not appear under the types of heterologous traits. The heterologous organs exert the same functions but necessarily do not have the similar morphological features. The heterologous organs vary in anatomy and development source they do not associate from a common inherited origin.

Note: Heterologous organs are the contrary of the homologous organs that exhibit similar functions but originate from different ancestral origins. The wings of birds, insects and bats are some of the appropriate examples of the heterologous trait.