There Are Cases,particularly in Fruit Flies,in Which a Normal Body

Multiple Choice

There are cases,particularly in fruit flies,in which a normal body part grows in the wrong spot.For instance,legs on the head growing instead of antennae,or a second set of wings behind the normal pair.What can explain this?

A) These are due to the reappearance of stem cells,which are totipotent.
B) These are due to misregulation of hormones from environmental contamination with pesticides.
C) These occur as a result of mutations in homeotic genes,which normally act to direct development along the anterior-posterior axis.
D) These naturally occur sometimes in animals that have metamorphic development,due to different organization of homeotic gene expression in larvae versus adults.