Question

Give any two striking similarities in the structure of embryos of all vertebrates.

Answer 1

1. All vertebrate embryos develop a notochord at an early stage. The notochord is partly or fully replaced by the vertebral column in the adult vertebrates.
2. All vertebrate embryos develop gill-clefts. In adults, these gill-clefts close in amphibians, reptiles, birds, and mammals, though they are functional in some aquatic vertebrates.