Question

Choose the correct answers from the alternatives given .
The gill slits of reptile and bird embryos are

• A. vestigial structures
• B. support for ontogeny recapitulates phylogeny
• C. homologous structures
• D. evidence for the degeneration of unused body parts

Answer 1

The correct option is C homologous structures

If two or more species share a unique physical feature, such as a complex bone structure or a body plan, they may all have inherited this feature from a common ancestor. Physical features shared due to evolutionary history (a common ancestor) are said to be homologous.

Some homologous structures can be seen only in embryos. For instance, all vertebrate embryos (including birds, reptiles) have gill slits and a tail during early development. Homologous embryonic structures reflect that the developmental programs of vertebrates are variations on a similar plan that existed in their last common ancestor.

So, the correct option is 'homologous structures'.