Name ________________________
Period_____
Date_________
Dragon Genetics
In dragons, the ability to breathe fire is a
recessive trait (dd). Homozygous dominant
dragons (DD) cannot produce fire or smoke at
all. Heterozygous dragons (Dd) can produce
smoke, but no fire.
1. Cross a fire breathing dragon with a
homozygous dominant dragon. Use a Punnett
square to support your answer.
What are the resulting genotypes? Give the
percentages.
What are the resulting phenotypes? Give the percentages.
2. Cross two smoke-producing only dragons (Dd). Use a Punnett square to support your
answer.
What percentage of the offspring can produce fire?
What percentage of the offspring can’t produce fire?
3. In dragons, the presence of horns (H) is dominant over no horns (h). If a heterozygous
horned dragon mates with a homozygous hornless dragon, what are the offspring’s
genotypes and phenotypes?
What are the resulting genotypes? Give the percentages.
What are the resulting phenotypes? Give the percentages.
4. In fire breathing dragons, the color of their fire is an inherited trait. Orange fire (B) is
dominant over blue fire (b). If a dragon with blue fire mates with a homozygous dragon
with orange fire, what percentage of the offspring would breathe orange fire
What percent of the offspring would breathe blue fire?
What percent of the offspring would breathe
orange fire?
5. Wing length in dragons is an inherited trait. Long wings (L) are dominant over short
wings (l). Based on the Punnett Square below, determine the parents’ genotypes and
phenotypes.
LL
Ll
Ll
ll
Parent’s Genotypes
Parents’ Phenotypes
Extra Credit
Imagine that you are a dragon breeder. You decide that you want a fire breathing dragon
that breathes blue fire, has horns and has long wings. Based on the information below, write the
possible genotypes for each of your desired phenotypes.
Create Punnett Squares for two of the traits listed above to show what the parental
genotypes could be to produce the desired trait. There can be more than one possibility for each
parental genotype- choose only one for the Punnett Square. Write the two traits you choose next
to Trait 1 & Trait 2.
Optional: Draw a picture of your dragon!
Information
- The inability to breathe fire (D) is dominant over breathing fire (d). Fire breathing is a
recessive trait in dragons.
- Homozygous dominant dragons (DD) cannot produce fire or smoke at all. Heterozygous
dragons (Dd) can produce smoke, but no fire.
- Having horns (H) is dominant over not having horns (h).
- Orange fire (B) is dominant over blue fire (b)
- Long wings (L) are dominant over short wings (l).
Desired Offspring Phenotypes
Fire breathing
Blue fire
Horned
Long Wings
Possible Genotype(s) For Offspring
________________
________________
________________
________________
Punnett Squares
Indicate a possible parental genotype for each parent that would produce a dragon with
all the desired traits.
Trait 1:
Trait 2:
Extra Credit
Imagine that you are a dragon breeder. You decide that you want to breed the two
dragons that you have, but you aren’t sure what the offspring will look like. You want to breed a
heterozygous long winged male that is heterozygous for breathing orange fire with a
heterozygous long winged female that is heterozygous for breathing orange fire. Create a
dihybrid Punnett Square to determine the offspring’s genotypes and phenotype ratios.
Create Punnett Squares for two of the traits to show what the parental genotypes could
possibly be to produce the desired trait. Write the two traits you choose next to Trait 1 & Trait 2.
Optional: Draw a picture of your dragon!
Information
- Orange fire (B) is dominant over blue fire (b)
- Long wings (L) are dominant over short wings (l).
Male Gametes
Female Gametes
Phenotypic Ratios: How many, out of 16:
_______________
Breathe orange fire
& have long wings
_______________
Breathe orange fire
& have short wings
_______________
Breathe blue fire
& have long wings
_______________
Breathe blue fire
& have short wings