Biological Science 6th Edition by Scott Freeman,Kim Quillin,Lizabeth Allison,Michael Black,Greg Podgorski,Emily Taylor,Jeff Carmichael

Exercise 4

What evidence suggests that changes in the way the PHAN gene is expressed could be partly responsible for evolutionary changes in leaf shape?
A) If PHAN gene expression is manipulated experimentally, individuals produce leaf types found in different species.
B) Experiments have shown that PHAN plays a role in establishing the upper-lower surface axis in leaves.
C) Sequencing studies and other data have shown that PHAN encodes a regulatory transcription factor.
D) All plant species surveyed to date have a gene homologous to PHAN.