A Recent Study of the Effects of the General Anesthetic

A recent study of the effects of the general anesthetic isoflurane suggests that it has a direct impact on an organism's biological clock. This study focused on honeybees because their clock genes are similar to those found in mammals. Prior to the start of this study, bees were trained to fly to an artificial flower to obtain sugar water and then return to the hive. In this study, researchers caught the bees as they approached the artificial flower. Half of the bees were anesthetized, and the other half were contained and not allowed to return to the hive immediately. After six hours, when all the anesthetized bees had awoken, both groups of bees were released. Honeybees use the sun to navigate, and their biological clock allows them to correct for the time of day. The bees that were not anesthetized flew directly to the hive, making adjustments for the time of day. However, those that were anesthetized made adjustments as if the time were hours earlier and flew at the wrong angle. Doctors report that people often emerge from general anesthesia disoriented in time and may sleep fitfully for a while afterward. Based on the honeybee study, researchers are looking into ways to keep the internal clock ticking normally even during surgery. Both honeybees and birds have wings for flight; thus, these structures are homologous in the two animal groups.

A) true, because the wings have a similar function and thus must be anatomically similar
B) false, because the wings look very different between the two groups
C) true, because all animals have a common ancestor
D) false, because birds and honeybees do not share a common ancestor from which this trait was derived