Why do negative essay results not always mean the molecule is absent

The similarities of organisms in which two areas numbered above provide the best evidence for common ancestry between organisms in both locations?

The wings of insects, birds, and bats evolved independently but carry out similar functions. this is an example of a. analogous structures. b. embryonic structures. c. vestigial structures. d. homologous structures.

Where can dna be found in a prokaryotic cell