Chapter 1, Problem 16P

A single zebrafish gene function was inactivated completely by mutation, and a zebrafish with this mutation had none of its normal horizontal stripes. For each of the following statements, indicate whether the statement is certainly true, certainly untrue, or if there is insufficient information to decide.

a.	The normal gene function is required for the viability of the zebrafish.
b.	The normal gene function is required for the formation of stripes.
c.	The normal gene function is required to make the pigment deposited in the stripes.
d.	The gene is required in zebrafish only for stripe formation.