Question

explain homologous organ analogous organ and fossil

Answer 1

homologous organs- organs which have the same structure and origin but different functions. eg the Forelimbs of humans, frogs, lizards, birds . Human being use it for holding, frogs use it for leaping, lizards use it for crawling and birds use it for flying.
analogous organs- organs which have same function but different structure and origin.
eg birds and butterfly both of them use it for flying but birds are vertebrate while butterfly are invertebrate.
fossil- remains or remanants of past organisms. sometimes they r found in the form of impressions.

Answer 2

Those organs which have the same basic structure and but different than functions are called homologous organs , Analogous organs are the organs which have different basic structure but have similar appearance and perform similar functions are known as Analogous organs, Fossils are the remains of dead animals or plants that lived in the remote past are known as Fossils