The abdominal segments of Drosophila have no appendages. Loss of function of bithorax genes results in appendages forming in these abdominal segments. Therefore, __________.
A)bithorax mutations are necessarily recessive
B)bithorax genes normally activate appendage-forming genes
C)ultrabithorax usually acts to oppose bithorax genes
D)bithorax normally activates a gene that negatively regulates appendages in the abdomen
E)expression of bithorax wild-type genes suppresses all appendage formation

Question

Quizplus · Accepted Answer

Bithorax genes normally function to suppress appendage formation in the abdomen, so their loss of function leads to appendage formation.

The Abdominal Segments of Drosophila Have No Appendages