Final answer:
The statement is true; homeobox genes, or Hox genes, were first discovered in the fruit fly and are responsible for the proper development of organs, which can result in drastic changes like legs growing in place of antennae when mutated.
Step-by-step explanation:
True: Homeobox genes, specifically known as Hox genes in fruit flies (Drosophila melanogaster), were discovered to play a crucial role in determining the placement and development of organs. When these genes mutate, they can cause one organ to develop into a completely different organ, as observed in fruit flies where a mutation in a Hox gene resulted in a leg developing where an antenna should have. The mutation of Hox genes is a fascinating event that can lead to significant and sometimes bizarre changes in an organism's body plan. Hox genes are highly conserved across different species and provide critical instructions during the embryonic stage. They code for transcription factors that bind to DNA, controlling the activation of other genes necessary for proper development. This regulation is vital for organismal development, so that body structures, such as limbs or antennae, form in appropriate locations.