elastic rebound. I know this because I learned it in 8th grade. :)
Answer: option c - in the coding region of the Pitx1 gene
Explanation:
Note that there is LACK OF SPINE, not the presence of defective spine; so, an heritable mutation must have occurred in the coding region of pix1 gene of freshwater sticklebacks resulting in absolute LACK OF SPINE
During interphase, cell growth occurs