Question

The embryos of fish, chickens, and rabbits have gill slits during their

early development. These homologous structures develop into gills in
fish. However, in chickens and rabbits, they either disappear or
develop into other body parts later in embryonic development. Which
of the statements below best explains the presence of homologous
structures in the embryos of these three different species?

Answer 1

The presence of homologous structures in the embryos of fish, chickens, and rabbits can be explained by the fact that these structures have a common evolutionary origin. While fish retain and develop gills from these structures, chickens and rabbits either lose them or they develop into other body parts later in embryonic development.

Step-by-step explanation:

During embryonic development, the embryos of fish, chickens, and rabbits have gill slits. These structures are homologous, meaning they have a common evolutionary origin. However, while fish retain and develop gills from these slits, chickens and rabbits either lose them or they develop into other body parts later in embryonic development.

This is because evolutionary changes in the genetic code can cause modifications in embryonic development, resulting in different structures in different species.