Question

1. rudolph, the red - nosed reindeer has two black - nosed parents. draw a punnett square that describes how two black - nosed reindeer can have a red - nosed baby write the probabilities of each phenotype in the space provided.

red - nose ___%.
black - nose ___%.

1. mendel knows how important it is for santa’s reindeer to fly. prancer can fly, but her mate is a heterozygous non - flyer named larry. draw a punnett square to show the probability that their offspring will be able to fly?

flyer ___%.
non - flyer ___%.

1. santa recently learned of two islands where the first magical reindeer came from. all of the reindeer on one island were purebred for tall antlers and all of the reindeer on the other island had pure short antlers. he brought all of these reindeer together in the north pole and they produced over 1,000 baby reindeer! when santa saw that all of the babies had tall antlers, he was scared that short - antlered reindeer would go extinct. use two punnett squares to show santa that just because all had tall antlers, it didn’t mean that the short - antlered reindeer were extinct. explain your answer in the space provided.
2. in the space to the right, draw a reindeer with the following genotype:

aa nn ff

Explanation:

Step1: Analyze Question 21

We have two black - nosed parents (genotype Bb each, since they can have a red - nosed offspring which is a recessive trait, so red - nosed is bb). The Punnett square is set up with one parent's alleles (B and b) on the top and the other parent's alleles (B and b) on the side.

• The Punnett square has four cells: BB, Bb, Bb, bb.
• The phenotype for BB and Bb is black - nosed (since B is dominant), and bb is red - nosed.
• Number of black - nosed genotypes: 3 (BB, Bb, Bb), number of red - nosed genotypes: 1 (bb).
• Probability of red - nose: $\frac{1}{4}=25\%$, probability of black - nose: $\frac{3}{4} = 75\%$.

Step2: Analyze Question 22

Prancer can fly, let's assume the allele for flying is F (dominant) and non - flying is f (recessive). Larry is heterozygous non - flyer? Wait, no, the problem says Larry is a heterozygous non - flyer? Wait, re - reading: Prancer can fly, her mate Larry is a heterozygous non - flyer? Wait, no, maybe Prancer is homozygous dominant (FF) or heterozygous? Wait, the Punnett square drawn has one parent with alleles f and f (Larry, non - flyer, but heterozygous? Wait, no, the Punnett square has f on the side (two f's) and F and f on the top. Wait, maybe Prancer is FF (can fly, dominant) and Larry is Ff? No, the Punnett square shows the side as f and f, top as F and f. Wait, the offspring are Ff, ff, Ff, ff. So flyer (Ff) and non - flyer (ff). Number of flyer genotypes: 2, non - flyer: 2. So probability of flyer: $\frac{2}{4}=50\%$, non - flyer: $\frac{2}{4}=50\%$.

Step3: Analyze Question 23

First island reindeer: purebred tall (TT), second island: purebred short (tt).

• Generation 2: Cross TT and tt. The Punnett square gives all Tt (tall antlers, since T is dominant).
• Generation 3: Cross two Tt reindeer. The Punnett square has alleles T and t on top and T and t on the side. The genotypes are TT, Tt, Tt, tt. So in generation 3, we have a tt (short antlers) genotype, which means short - antlered reindeer are not extinct.

Answer:

• Question 21: Red - nose: 25%, Black - nose: 75%
• Question 22: Flyer: 50%, Non - flyer: 50%
• Question 23: In generation 2, all offspring are Tt (tall antlers). In generation 3, crossing Tt x Tt gives TT, Tt, Tt, tt. So short - antlered (tt) reindeer can appear in generation 3, so they are not extinct.