Homologous and vestigial organs that is option number 1 is the correct answer.
Homologous organs have a common origin and are built on the same basic fundamental principle but they have variant appearance and perform different functions as well. At the same time, Vestigial organs had important functions in the animals' ancestors and basically dont have much to do now.
Therefore option number 1 is correct.
Thank you.
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile