If you know that a Hox gene, AbdB, is expressed in the most posterior part of the abdomen in a Drosophila embryo, which of the following conclusions about a homologous gene in humans would most likely be correct?
A) There is no homologous gene to abdB in humans, because the evolutionary distance between humans and flies is so great.
B) The homologous gene to abdB exists in humans, but it is expressed only in adults, not in human embryos.
C) The homologous gene to abdB exists and is expressed in the head of human embryos.
D) The homologous gene to abdB exists and is expressed throughout the human embryo in roughly equal amounts.
E) The homologous gene to abdB exists and is expressed near the tail of the human embryo.

Question

Quizplus · Accepted Answer

The expression of abdB in the most posterior part of the abdomen in a Drosophila embryo suggests that it plays a role in specifying posterior identity. If a homologous gene exists in humans, it would likely also play a role in specifying posterior identity. Therefore, it is most likely that the homologous gene to abdB exists and is expressed near the tail of the human embryo.

If You Know That a Hox Gene, AbdB, Is Expressed