Question: Zebrafish are increased in fish tanks with one family per tank. The mutation spadetail is a recessive lethal. A stock tank for spadetail was made by crossing two carriers. The fish in the stock have grown up, and you are faced with identifying new carriers from the tank using random crosses.?

a. What is the frequency of carriers in a tank?!
b. How do you know when you ID carriers??
c. What can you say about the fish that you don’t ID?!