Biology Genetics Unit Name: ______

Dihybrid Parent Practice Date: ______Per: ___

Welcome to Planet Xenon! On Xenon, there are aliens with many unique traits listed in the table below. Use this table to answer the following questions.

Trait / Dominant Allele / Recessive Allele
Hair Length / Long (L) / Short (l)
Lip Color / Green (G) / Blue (g)
Hair Type / Mohawk (M) / Spiked hair (m)
Number of Eyes / Three eyes (T) / One eye (t)
Nose Type / Big nose (B) / Little nose (b)
Eye Color / Red (R) / Pink (r)

1.  A heterozygous long haired alien with one eye meets a pretty alien who is homozygous both short hair and three eyes.

a.  What are the genotypes of each alien? ______x ______

b.  What are the allele combinations each alien could pass on to their kids?
______and ______

2.  A homozygous green lip and homozygous little nose alien is married to a heterozygous green lip and heterozygous big nosed alien.

a.  What are the genotypes of each alien? ______x ______

b.  What are the allele combinations each alien could pass on to their kids?
______and ______

3.  An alien with one eye and spiked hair is dating an alien who is heterozygous for three eyes and also has spiked hair.

a.  What are the genotypes of each alien? ______x ______

b.  What are the allele combinations each alien could pass on to their kids?
______and ______

4.  Marty is an alien with heterozygous for both red eyes and three eyes. Her husband Max has the exact same genotype.

a.  What are the genotypes of each alien? ______x ______

b.  What are the allele combinations each alien could pass on to their kids?
______and ______

The results in the Punnett Square below are the possibilities that could result from a mating of an alien who is heterozygous for Mohawk hair and his three eyes with a spiked hair alien who is also heterozygous for three eyes.

mT / mt / mT / mt
MT / MmTT / MmTt / MmTT / MmTt
Mt / MmTt / Mmtt / MmTt / Mmtt
mT / mmTT / mmTt / mmTT / mmTt
mt / mmTT / mmtt / mmTT / mmtt

5.  What are the possible phenotypes of the offspring?

Hair Type Number of Eyes

______& ______

______& ______

Hair Type Number of Eyes

______& ______

______& ______

A newly wedded alien couple are dreaming of their future family, and wondering what their children might look like. The future father is homozygous for his big nose, but heterozygous for red eyes, while the future mother is heterozygous for her big nose and has pink eyes. Use the Punnett Square to determine the possible phenotypes for their children.

6.  Genotype of the father: ______Genotype of the mother:______

Br / br / Br / br
BR / BBRr / BbRr / BBRr / BbRr
Br / BBrr / Bbrr / BBrr / Bbrr
BR / BBRr / BbRr / BBRr / BbRr
Br / BBrr / Bbrr / BBrr / Bbrr

7.  How many offspring could have a big nose and red eyes?______

8.  How many offspring could have a little nose and red eyes?______

9.  How many offspring could have a big nose and pink eyes?______

10.  How many offspring could have a small nose and pink eyes?______

In the Punnett below, determine where each parent’s gametes are listed. The mother is heterozygous for both long hair and green lips whereas the father has short hair and is heterozygous for green lips.

11.  Genotype of the father: ______Genotype of the mother:______

lG / lg / lG / lg
LG / LlGG / LlGg / LlGG / LlGg
Lg / LlGg / Llgg / LlGg / Llgg
lG / llGG / llGg / llGG / llGg
lg / llGg / llgg / llGg / llgg