Name: _______________________________
Dolphin Genetics Activity
All photos taken by Jessica Conway under GA LOC permit No. 16104
Standard B-4.6: Predict the inherited traits by using the principals of Mendelian
genetics (including segregation, independent assortment, and dominance).
Background:
Bottlenose dolphins can either have rounded dorsal fins or pointed dorsal fins.
Dolphins with rounded fins have the genotype Rr or RR. Dolphins with pointed dorsal fins
have the genotype rr. Baby dolphins all have floppy fins when they are born, but as they
grow their fin will resemble their genotype.
Dolphins can become ill and die from lungworm parasites, similar to heartworms in
dogs. Some dolphin genotypes are immune to this parasite. Dolphins with pointed fins get
this parasite and dolphins with rounded fins do not. A population of dolphins cannot
survive if more than 60% of individuals are infected.
Scenario:
Its spring and all the baby dolphins are being born. There has been an outbreak of
lungworms in a small dolphin population in North Inlet. Your class is hired by the National
Marine Fisheries Service to figure out if this population will survive the outbreak. To do
that, you need to predict the genotypes of the baby dolphins being born by using punnett
squares and your knowledge of genetics.
Activity:
1. You will receive a dolphin card containing a picture of your dolphin, its mating symbol
and genotype. You will have to find the classmate who has the same mating symbol as you.
These two dolphins will produce offspring. Use your dolphin card to fill out the information
below:
Your dolphin’s genotype:_________________________
Your dolphin’s phenotype: ________________________
Your partner’s genotype: ___________________________
Your partner’s phenotype: ___________________________
2. Will your dolphin or your partner’s dolphin be infected by lungworms? How do you
know?
3. Perform a punnett square below to predict the genotype of your calf.
3. What is the probability of that your calf will have a rounded fin?
4. What is the probability that your calf will have a pointed fin?
5. What is the predicted genotype of your calf? (If the probabilities are equal, you can pick
one at random)
6. What is the phenotype of your calf? (If the probabilities are equal, you can pick one at
random)
7. Will your calf be infected with lungworms? How do you know?
Now lets look at the whole population by analyzing the class’ data. One person from your
group can record your data on the board.
8. Use the data on the board to fill out the bar graph below:
100
80
60
40
20
Genotype
8. Based on your graph, will the dolphin population survive? Why or why not?
End of activity questions:
1. In Labrador Retrievers, black is the dominant gene and brown is the recessive gene.
Indicate which of the following genotypes will be black and which will be brown:
BB _________________ Bb __________________ bb ___________________
2. If two black labs (both genotypes BB) mated, what is the probability that there will be a
brown puppy in the litter? Perform a punnet square to answer.
3. For each phenotype, give the genotypes that are possible for a dolphin fin.
Rounded fins (R) are dominant to pointed fins (r)
Round = _________________________ Pointed = _____________________________
4. There are 200 dolphins living in a cove. 50 of those dolphins have the recessive genotype.
A disease breaks out that only affects the dolphins with the recessive trait. The population
cannot survive if more than 60% of the population is affected. Will this population survive?
Why or why not?
Name: __________________________________
Pre MacMod
(1a). A person with brown eyes (genotype BB) mates with a blue-eyed person (genotype
bb). Which of the following outcomes most accurately describes color of their
children’s eyes? Circle your answer choice.
(a) All of the children will have blue eyes
(b) All of the children will have brown eyes
(c) Half of the children will have blue eyes and half will have brown eyes
(d) Most of the children will have brown eyes but a few may have blue eyes
(e) Most of the children will have blue eyes but a few may have brown eyes.
(1b). Explain your answer choice.
(2).
If possible use the terms dominant and recessive to explain the color of the
children’s eyes.
2. A population cannot survive if more than 60% of the individuals have the genotype bb. If
there are 150 individuals in the population, how many can have the genotype bb without
the population crashing?
Name: ____________________________________
Post MacMod
(1a).
Two bears with black fur mated and produced four offspring. Three of the cubs had
black fur and one cub had brown fur.
(1b). Explain how the cubs could have different colored fur.
(2).
If possible use the terms dominant and recessive to explain the color of the cubs
fur.
2. In a forest, there is a population of 45 bears. 30 of the bears are black and 15 of the bears
are brown. What percentage of the population consists of brown bears?
Teacher notes for dolphin genetics activity:
Each student gets a card with a dolphin, genotype and mating symbol. They will find the
other student in the class with the same mating card. (All of the cards will have a
male/female matching pair). These two will produce a calf. They will predict probability of
offspring by using a punnett square. If the probability is 50/50 they will pick a genotype.
They will then use the class’s data to figure out how much of the population will be affected
by a disease. If more than 60% of the population is affected, it won’t survive. They will use
class data (parent genotypes and their predicted calf genotypes) to make a graph and
interpret it to figure out if the population will survive.
Class data will be put on the smart board using a premade data chart in a powerpoint file.