You have already been given the genotypes of all the individuals involved. The easiest way to find out which cross will produce the fewest offspring with the undesirable trait is to perform two punnett squares, crossing the bull with each of the cows. Below are two blank squares for you to try the crosses and compare the offspring. You will not be able to use superscripts on these tables so use XN, Xn, and Y in your notation.

Your punnett squares should look similar to the one below. If they do not, review the material on gamete formation and how to set up the punnett square and try again. The cross with cow 1 is given first

	Xn	Y
XN	XNXn	XNY
XN	XNXn	XNY

	Xn	Y
XN	XNXn	XNY
Xn	XnXn	XnY

Now count up how many of each genotype and phenotype you have in the male offspring and in the female offspring from both crosses.

---

Return to the question page to select the correct answers.