The expression of the Pax-6 gene when vertebrate and fruit fly versions of the gene are exchanged between these animal groups illustrates __________.

• A. that the same gene can have very different functions in different types of animals
• B. that some coding genes have products other than proteins in different types of animals
• C. that the mechanisms of gene expression vary among different animal groups
• D. that a gene that plays a major role in the development of one type of organism often has a reduced role in another
• E. the common ancestry in the evolution of these animal groups

Answer: (E)

Verified step by step guidance

1. Begin by understanding the role of the Pax-6 gene. Pax-6 is a highly conserved gene involved in eye development across various species, including vertebrates and fruit flies.
2. Consider the concept of evolutionary conservation. This refers to genes that have remained relatively unchanged throughout evolution, indicating their importance in fundamental biological processes.
3. Examine the idea of common ancestry. The fact that Pax-6 can function similarly in both vertebrates and fruit flies suggests that these organisms share a common ancestor, from which they inherited this gene.
4. Reflect on the implications of gene exchange experiments. When the Pax-6 gene from one species is introduced into another, and it still functions, it demonstrates the evolutionary conservation and shared ancestry of these species.
5. Conclude that the expression of Pax-6 in different species illustrates the common ancestry in the evolution of these animal groups, as the gene retains its function across diverse organisms.