What are homologous organs ? Give one example. Can the wings of a butterfly and the wings of a bat be regarded as homologous ?

Structures which have a common basic structure but perform different functions are called homologous structures. e.g. fore limbs of reptiles, amphibians and mammals. Yes, they have common ancestor but variously...

(b)An example of homologous organs is our teeth and an elephant’s tusks.

Wings of a butterfly are composed of membrane, while wings of a bat are composed of bony skeleton. Hence, these are not homologous organs rather analogous organs.

A group of organic compounds having the same functional group and similar structures in which the successive members differ by CH2 group is called homologous series. Alkynes:C3H4,  C4H6,  C5H8 Alkenes: C3H6, C4H8,  C5H10

Organisms bearing both the sex organs in the same individual are called bisexual. Example, Hydra, Mustard.

The wings of a butterfly, and the wings of a bat cannot be considered as homologous organs because they have different basic designs even though they perform similar functions, they are therefore...

Analogous organs are those organs which have different structural designs and origin but perform similar functions. Homologous organs are those which have the same basic structural design and origin but perform...

D. forelimbs of a cow, a duck and a lizard

Analogous organs: Those organs which have different basic structural designs and origin, but perform similar functions are called analogous organs.  Homologous organs: Those organs which have the same basic structural design...

d. cell-mediated immune response