Jones
Biology
Name:
Period:
Date:
Genetics Problem Set 2
Bikini Bottom Genetics

Determine the genotype of the parents based on the percentage of the offspring’s phenotypes
and remember, nature does not give numbers. Example: 7 out of 12 is about half.
1.
Being a square sponge in Bikini Bottom is a dominant trait. SpongeBob Squarepants, of course, is
square. He meets SpongeSusie Roundpants. (Do I have to explain? ) They have eight little sponge
offspring and all their kids have SpongeBob’s square phenotype.
a. What is the probable genotype of SpongeBob? __________
b. What is the genotype of SpongeSusie? _________
c. What are the genotypes of their offspring? __________
d. What is the phenotypic ratio? ______________________
2. Patrick, though he is pretty stupid, is a catch with the ladies. While playing “hooky” in the fishing
lines, he meets his true love Patricia. Patrick expresses dominance with his pink body color and
Patricia is purple. They have six kids; half of the kids are pink and half of them are purple.
a. What is the probable genotype of Patrick? __________
b. What is the probable genotype of Patricia? _________
c. What are the genotypes of the offspring? ____________________
d. What is the phenotypic ratio? _______________________
3. Mr. Krabs can’t get enough of Mrs. Puff. He even can’t control spending his hard earned money on her.
In crabs and puffer fish, right-handedness is due to a dominant allele. If Mr. Krabs is right-handed,
whose mother is left-handed, has offspring with Mrs. Puff who is left-handed, what will the results be
for their offspring?
a. What is the probable genotype of Mr. Krabs? _________
b. What is the probable genotype of Mrs. Puff? _________
c. What are the possible genotypes of their offspring? _________________
d. What is the genotypic ratio? _____________________
4. Plankton even has some happiness in Bikini Bottom despite his inability to get his hands on the Krabby
Patty recipe. Plankton produce a lot of offspring at once to ensure their success for survival in the
sea. Plankton’s wife is a computerized robot so the odds for the offspring’s survival vary. They have
100 computerized-plankton offspring. 78 of their kids have are evil and 22 of their kids are kind to
others. Considering the gene for “evilness” is dominant, answer the following questions.
a. What is the probable genotype of Plankton? ___________
b. What is the probable genotype of his robotic wife? __________
c. What are the possible genotypes of their offspring? ________________________
d. What is the genotypic ratio? ___________________________
e. What is the phenotypic ratio? __________________________
5. Everyone is Squidward’s family has light blue skin. He found a soul mate named Squidrina who is
sophisticated enough to marry. She even plays the clarinet. Squidrina has light blue skin. Her
mother has light green skin and her father has light blue skin.
a. What is probable genotype of Squidward? ___________
b. What is the probable genotype of Squidrina? ___________
c. What are the probable genotype(s) of their future offspring? __________________
d. What are the probable phenotype(s) of their
future offspring? _______________________
6. Well, 7 years has passed and Mr. Krabs and Mrs. Puff didn’t work out. The fact that they were two
different species complicated things. Mr. Krabs moved on and married his own kind, another crab.
They had a baby and Mr. Krabs has been upset since he saw his baby that had short eye stalks. Mrs.
Krabs claims that the hospital goofed up and mixed up their baby with someone else’s baby. Mr. Krabs
is homozygous dominant for his tall eye stalks while his wife also expresses tall eye stalks. Her dad
has short eye stalks.
a. What is the genotype of Mr. Krabs? __________
b. What is the genotype of Mrs. Krabs? _________
c. What are possible genotypes of the offspring they would produce? ___________________
d. What is the possible phenotypes of the offspring they would produce? ____________________
e. Did the hospital make a mistake? Explain your answer.