Inheritance: It Runs In the Family
Introduction
You are going to use an online learning object to explore the heritable
characteristics of fruit flies. A heritable characteristic is one that is passed on
from generation to generation. Fruit flies have heritable characteristics such as
straight wing/curled wing and red eyes/brown eyes that can be easily identified.
You will complete a simulation that will have you examine several combinations
of heritable characteristics to determine whether they are dominant or recessive
traits.
Problem
Inheritance: It Runs In the Family
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Procedure
Test I Pure Red Eyed X Pure Brown Eyed
1.
2.
3.
4.
5.
6.
Click on the diagram above to launch the learning object.
Mouse over the fruit fly (DMG) on the top shelf and follow his
instructions. You will be repeating the steps of his instructions several
times, so try to remember them.
Place a pure red eyed female and a pure brown eyed male in the
breeding vial.
Record your prediction for pure red eyed and pure brown eyed
parents in the Data Table provided.
Follow DMG's instructions and observe the offspring with the
binocular microscope. Separate the offspring into red eyed and
brown eyed groups.
Record your observed count for pure red eyed/pure brown eyed
offspring in the data table.
Test 2 Hybrid Red Eyed X Hybrid Red Eyed
Place a hybrid red eyed female and a hybrid red eyed male in the
breeding vial.
Record your prediction for hybrid red eyed parents in the Data Table
2.
provided.
Follow DMG's instructions and observe the offspring with the
3. binocular microscope. Separate the offspring into red eyed and
brown eyed groups.
Record your observed count for pure red eyed/pure brown eyed
4.
offspring in the data table.
1.
Test 3 Pure Straight Wing X Pure Curled Wing
Place a pure straight wing female and a pure curled wing male in the
breeding vial.
Record your prediction for pure straight wing and pure curled wing
2.
parents in the Data Table provided.
Follow DMG's instructions and observe the offspring with the
3. binocular microscope. Separate the offspring into straight wing and
curled wing groups.
Record your observed count for pure straight and pure curled wing
4.
offspring in the data table.
1.
Inheritance: It Runs In the Family
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Test 4
1.
2.
3.
4.
5.
Hybrid Straight Wing X Hybrid Curled Wing
Place a hybrid straight wing female and a hybrid straight wing male in
the breeding vial.
Record your prediction for hybrid straight wing parents in the Data
Table provided.
Follow DMG's instructions and observe the offspring with the
binocular microscope. Separate the offspring into straight wing and
curled wing groups.
Record your observed count for hybrid straight wing offspring in the
data table.
Complete the inference section at the bottom of the data table.
Observations
Predicted Count
(out of 8)
red eyed
pure red
pure brown
1
brown
eyed
eyed
eyed
red eyed
hybrid red
hybrid red
2
brown
eyed
eyed
eyed
pure straight pure curled straight
3
wing
wing
curled
hybrid
hybrid straight straight
4
straight wing wing
curled
Test
Parent 1
Parent 2
Observed Count
(out of 8)
red eyed
brown
eyed
red eyed
brown
eyed
straight
curled
straight
curled
Analysis
1. What heritable traits of fruit flies are dominant?
What parent combination would produce offspring that all have brown
2.
eyes?
Big DMG has brown eyes and curled wings but his parents and
3. siblings have red eyes and straight wings. Is this possible? What trait
combination of traits in his parents would produce this result?
Extension
You have done four simulations with two heritable traits of fruit flies. You can now
see that the ratio of offspring that result from different combinations of these
traits is predictable. What parent combination might result in an equal number of
offspring having straight and curled wings? Use the Explore mode of the learning
object to set up and test your prediction.
Inheritance: It Runs In the Family
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Credits
The learning object was developed by LearnAlberta and can be found in the
Cyber-Science section for Grade 9.
Inheritance: It Runs In the Family
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