Name:_______________________________________
Period:__________
PUNNETT SQUARES: ALIEN ENCOUNTER
ATTENTION: There has been a security briefing in Area 51, the United States’ contained secret
laboratory. We are not sure if someone let the experiments out or if the experiments let
themselves out, but never mind that, we’ve got bigger problems on our hands! Our country’s
secret projects are on the loose, most of them are weird and unknown aliens and monsters;
some which were brought to Earth through asteroids from outer space and others born from a
test tube. These creatures are not friendly, stable or safe.
MISSION: The scientists at Area 51 are sworn to secrecy about their work and experiments.
However, due to the current situation, they are disclosing the list of monsters and aliens to you,
a National Scientist. The President of the United States has appointed you to predict the worst
offspring imaginable should 2 of these monsters reproduce. You have 20 minutes, good luck.
DIRECTIONS:
1.) Pick two monsters from the list below: Circle the two you choose
-Kirby, Chicken Little
-Green Man
-Experiment 626 aka Stitch
-Chewbacca
-Smirf
-Toy Story Aliens
-Neytiri, Avatar
2.) Decide which alleles are dominant and recessive between the two monsters (at least two
traits must have dominant-recessive alleles). You need to cross four traits (5 for extra credit)
Trait
Eye color
# of eyes
Skin color
Skin/fur/hair
Number of
fingers
Antennae
DOMINANT
Symbol
3.) Cross each pair of traits in a Punnett Square
4.) Create you monster! Draw on attached sheet
Recessive
Symbol
Cross #1
Trait you are crossing: _________________________
DOMINANT allele: ___________ symbol: _____
Recessive allele:___________ symbol : _____
Outcome after cross:
______% dominant
______% recessive
______% dominant-recessive
Appearance: allele with highest percentage after cross
Cross #2
Trait you are crossing: _________________________
DOMINANT allele: ___________ symbol: _____
Recessive allele:___________ symbol : _____
Outcome after cross:
______% dominant
______% recessive
______% dominant-recessive
Appearance: allele with highest percentage after cross
Cross #3
Trait you are crossing: _________________________
DOMINANT allele: ___________ symbol: _____
Recessive allele:___________ symbol : _____
Outcome after cross:
______% dominant
______% recessive
______% dominant-recessive
Appearance: allele with highest percentage after cross
Cross #4
Trait you are crossing: _________________________
DOMINANT allele: ___________ symbol: _____
Recessive allele:___________ symbol : _____
Outcome after cross:
______% dominant
______% recessive
______% dominant-recessive
Appearance: allele with highest percentage after cross
** If you want to do a fifth cross for extra credit, complete it on the bottom of the front page **