Download Name __Date_____________ “Practice Makes Perfect! ” Punnett

Name _________________________________________________________Per________Date_____________
“Practice Makes Perfect! ” Punnett Squares
Please answer on your own sheet of paper!
You must include a key for each problem, a cross for each Punnett square, and you must show all work!
Once Upon A Time….
1. Snow White has a special fondness for apples. Her favorites are the true-breeding red delicious apples
produced by the seven dwarfs. Doc, the scientist of the group, has recently tried crossing the red delicious
apples loved by Snow White, with a true-breeding group of golden delicious apples. In apples, red color is
dominant and golden is recessive.
a. Construct a Punnett square to show F1. What are the expected genotype and phenotype ratios?
b. Construct a Punnett square to show F2. What are the expected genotype and phenotype ratios?
c. If Doc collects a dozen apples from the F2 generation for Snow White, how many red and how many
golden apples would be in the basket?
2.
Cinderella is so happy! She is marrying her Prince Charming and preparations are underway for the wedding
ceremony. She wants everything to be perfect, right down to the flowers. Her favorite colors are pink and red,
but alas – only pink roses are available. Not only is Cinderella an excellent housekeeper, she also has a
background in Biology, so she directs the palace gardeners to cross pink roses with pink roses. She knows that
roses show incomplete dominance and that pink roses have a heterozygous genotype, while one homozygous
genotype shows red roses and the other homozygous genotype shows white roses.
a. Construct a Punnett square for the cross of pink roses X pink roses.
b. What is the expected phenotype ratio? Will Cinderella have pink and red roses for her wedding?
3.
Sleeping Beauty is known throughout the kingdom for her beautiful homozygous ruby red lips and golden hair.
The prince that has awakened her from her slumber has heterozygous red lips and heterozygous black hair. Red
lips are dominant and pink lips are recessive. Black hair is dominant and blonde hair is recessive.
a. Construct a dihybrid cross to determine what their children might look like.
b. What are the expected genotype and phenotype ratios?
4.
A missing persons report has been filed on a young woman named Rapunzel, rumored to have been kidnapped
and held captive in a tower. When detectives storm and search the tower, Rapunzel is gone, but they find a
footprint left behind. The footprint clearly shows a loop pattern on the big toe. A loop pattern is a recessive
trait. Detectives question Rapunzel’s family to determine if the footprint might belong to Rapunzel. The
investigation provides the following information:
Rapunzel’s dad does not have the foot loop (not fruit loop, but foot loop!) pattern
Rapunzel’s mom does not have the foot loop pattern
Rapunzel’s sisters do not have the foot loop pattern
Rapunzel’s brother does have the foot loop pattern
a. What is the genotype of Rapunzel’s mother? Rapunzel’s father?
b. Construct a Punnett square to determine if the footprint could belong to Rapunzel.
c. What is the probability that Rapunzel has a foot loop pattern?
More Practice…..
5. In monsters, eye color is a trait that exhibits co-dominance. Monsters that are RR have red eyes, those that are
YY have yellow eyes, and monsters that are heterozygous have red AND yellow freckled eyes. If a yellow-eyed
monster marries a monster with red AND yellow freckled eyes, what are the expected genotype and phenotype
ratios of their mini-monsters (children)?
Mortimer and Matilda Monster have three children, Mavis has red AND yellow freckled eyes, Mabel has red
eyes, and Mort Jr. has yellow eyes. Use the phenotypes of the children to determine the genotypes of the
parents, Mortimer and Matilda.
6. Count Dracula is looking for a mate. He comes from a pure-line family with the dominant trait of very sharp
fangs. It is important to Dracula to find a wife who shares the same family background. In the world of
vampires, not only are sharp fangs considered extremely attractive, their ability to survive depends on them! 
He has met someone that he thinks could be the vampire of his dreams (or would that be nightmares?!). Dolly
has fangs as sharp as razor blades, but Dracula wants to make sure they have no chance of producing baby
vampires with dull fangs. When Dracula visits Dolly’s house, he snoops and discovers the highly-prized
certificate of pure-line sharp fangs awarded to Dolly’s father, but he is horrified to discover that Dolly’s mother
has dull fangs!
a. What are the genotypes of Dolly’s parents?
b. What is Dolly’s genotype?
c. Construct a Punnett square to determine the expected genotypes and phenotypes if Dolly and
Dracula marry and have children.
7. In ghosts, white color is dominant over gray color, and a rounded-head is dominant over a pointed head. If a
gray ghost with a pointed head marries a ghost heterozygous for body color and head shape, determine the
expected genotype and phenotype ratios in the ghostettes (little ghosts) produced.
Matching
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Combination of alleles that contains a dominant and recessive
Study of heredity
Haploid reproductive cells
Humans have 23 pairs of these
Unit on a chromosome; contains a unique sequence of DNA
that results in a trait
Type of allele that is always expressed when present
Separation of alleles when homologous pairs separate
Having two of the same alleles
Traits passed on from parents to offspring
Outward appearance of an organism
Characteristic that distinguishes one individual from another
Different forms of a gene
Type of allele that is masked when there is only one present
Genetic composition of an organism
Exchange of genetic information in prophase I of meiosis
Fertilized ova
Cell that contains pairs of chromosomes, 2n
A.
B.
C.
D.
E.
F.
G.
H.
I.
J.
K.
L.
M.
N.
O.
P.
Q.
R.
Allele
Chromosomes
Crossing over
Diploid
Dominant
Gamete
Gene
Genetics
Genotype
Haploid
Heredity
Heterozygous
Homozygous
Law of segregation
Phenotype
Recessive
Trait
Zygote
Name the Process – Identify each characteristic as occurring in mitosis, meiosis, or both.
_____________________18. Homologous pairs join together
_____________________19. Produces gametes
_____________________20. DNA thickens, coils, and condenses
_____________________21. Produces clone cells that are 2n
_____________________22. Only occurs in testes and ovaries
_____________________23. In humans, produces cells with 23 chromosomes
_____________________24. Sister chromatids pulled apart by shortening of kinetochore microtubules
_____________________25. Occurs to replace old and worn out cells
_____________________26. Two cell divisions
_____________________27. DNA replication occurs