試題詳解

10. A genetic change that caused a certain Hox gene to be expressed along the tip of a vertebrate limb bud instead of further back made possible the evolution of the tetrapod limb. This type of change is an illustration of ________.
(A) heterochrony, a change in the timing of developmental events
(B) allopolyploidy, an increase in chromosome number
(C) paedomorphosis, or retention of ancestral juvenile structures in an adult organism
(D) a change in a homeotic developmental gene that altered the spatial organization of body parts
(E) allopatric speciation