What are Groups and Sub-groups?
- Appearance and function are the two different criteria based on which similarities are identified between two
- A particular living species that share many characteristics with humans is in close relation with
- Characteristics which can classify most of the living organisms are called Groups. They contain distant
- Within the groups, there are closely related organisms which share many characteristics. These organisms are classified into categories called Sub-groups.
What is the difference between a close relative and a distant relative?
- An organism sharing about 70% of its characteristics with another organism is its close relative because it shares many more common characteristics with the other
- An organism sharing only 25% of its characteristics with another organism is its distant relative because it shares fewer characteristics with the
What are Homologous organs and Analogous organs?
- Homologous organs – If two organs share the same physical appearance but are slightly modified, they are called Homologous organs.
For example,
The arm of a human, the leg of a dog, and the wing of a bird are homologous structures. They are different and have a different purpose, but they all are similar and share common traits.
Homologous organs
- Analogous organs – The organs that have the same functions but are different in their appearance are called Analogous organs.
For example,
The wing of a bat and the wing of a bird are analogous. They appear different externally and the internal skeleton is also different but both are used for flying.
