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Andrianopoulos/Friel/McCloud/McHugh/Shoub
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Date _______________ Per. 1 2 3 4 5 6 7 8
Gregor Mendel
“Father of Genetics”
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Genetics
January 3, 2012— February 8, 2012
Week 1
Monday, Jan. 2
Tuesday, Jan. 3
Wednesday, Jan. 4
Thursday, Jan. 5
Friday, Jan. 6
Winter Break - No School!!!
Discuss Genetics Critical Learning Standards (pkt. p. 5-6)
Genetics Grabber - Blue People of Troublesome Creek (show picture)
Begin reading Article (pkt. p. 7-13)
Homework
 Finish Article and Answer Questions (pkt. p. 7-13)
Meiosis PPT or Note Sheet
Begin Everything I want to know about Meiosis (pkt. p. 15-16)
Homework
 Read Ch. 11.4 (textbook p. 275-278)
 Complete Everything I want to know about Meiosis (pkt. p. 15-16)
Check Homework
Introduction to Genetics PPT
Homework
 Read Ch. 11.1 (textbook p. 262-266)
 2CN (pkt. p.17-20)
Basic Genetics: Writing Keys and Genetics Vocab (pkt. p. 21-25)
Homework
 Practice Writing Genotypes for Dominant and Recessive Alleles (pkt. p. 1215)
Week 2
Monday, Jan. 9
Tuesday, Jan. 10
Wednesday, Jan. 11
Review Homework
Assign Genetic Frayer Cards
Lab: Determination of Genotype and Phenotype in Human Traits
Homework
 Work on Genetic Frayer Cards
Gather Class Data for Bar Graph
Finish Lab Discussion Questions
Homework
 Finish Graph Lab Discussion Questions
 Study – Quiz tomorrow on genetic keys and vocabulary!
Genetics Quiz #1
Introduce Genetic Crosses (PPT)
Model Monohybrid Crosses: Punnett Square Exercises (pkt. p. 27)
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Thursday, Jan. 12
Friday, Jan. 13
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Homework
 Monohybrid Practice Problems (pkt. p. 28-30)
Review Genetics Quiz #1
Go over Homework
Genetics Video
Homework
 STUDY FOR FINALS!
Review for Finals
Homework
 STUDY FOR FINALS!
Finals Week
Monday, Jan. 16
Tuesday, Jan. 17
Wednesday, Jan. 18
No School – Martin Luther King Jr. Day
Review for Finals
Homework
 STUDY FOR FINALS!
FINALS Periods 1-3
Thursday, Jan. 19
FINALS Periods 4-6
Friday, Jan. 20
FINALS Periods 7-8
Week 3
Monday, Jan. 23
Tuesday, Jan. 24
Wednesday, Jan. 25
Thursday, Jan. 26
No School – Teacher Institute
Welcome Back to 2nd Semester
Check Schedules/Seating Chart
Review Monohybrid Crosses
Create a Kid Lab (pkt. p. 31-15)
Homework
 Read Ch. 11.3 (textbook p. 270-274)
 2 CN (pkt. p 37-40)
Finish Create a Kid Lab (pkt. p. 25-29)
Homework
 Study – Quiz tomorrow on Monohybrid Crosses
Genetics Quiz #2
Teach Incomplete Dominance and Codominance (PPT option)
Practice Problems (pkt. p. 41 and 44)
Homework
 Incomplete Dominance Practice Problems (pkt. p. 42-43)
 Codominance Practice Problems (pkt. p. 45-46)
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Friday, Jan. 27
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Review Genetics Quiz #2
Review Homework
Blood Type Lab
Homework
 Work on Genetics Frayer Cards
Week 4
Monday, Jan. 30
Tuesday, Jan. 31
Wednesday, Feb. 1
Thursday, Feb. 2
Friday, Feb. 3
Teach Multiple Allele Problems (PPT)
Multiple Allele Practice Problems (pkt. p. 47-48)
Homework
 Finish Multiple Allele Practice Problems (pkt. p. 49-50)
Review all problems
Work day on Practice Problems
Homework
 Work on Genetics Frayer Cards
 Study - quiz on Codominance/Incomplete Dominance/Multiple Alleles
Quiz #3
Introduce Pedigrees and Sex Linkage (PPT)
Practice Problems (pkt. p. 51 and 53-54)
Homework
 Pedigree Practice Problems (pkt. p. 52)
 Sex Linkage Practice Problems (pkt. p. 55-57)
Pedigree Activity on CF (pkt. p. 59-60)
Homework
 Finish Pedigree Activity and answer Analysis Questions (pkt. p. 59-60
Work on Genetics Study Guide
Homework
 Genetics Study Guide – due Tuesday
Week 5
Monday, Feb. 6
Tuesday, Feb. 7
Review Genetics Concepts - Reebop Lab
Homework
 Finish Reebop Analysis Questions
Check Study Guide
Review Genetics Unit
Homework
 Study – Genetics Test Tomorrow
Wednesday, Feb. 8
Genetics Test
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Course: S137 Biology
Unit: Genetics
Time Frame: Semester 1/2 – 4 weeks
Course Critical Learning Standard:
V. Genetics
a. Meiosis
1. Genetic Variation
2. Haploid vs. Diploid
b. Simple Dominance
1. Monohybrid Cross
2. Genotype/Phenotype
c. Incomplete Dominance vs. Simple Dominance
d. Pedigrees
1. Identifying individuals
2. Genotypes/phenotypes based on diagram
e. Multiple Alleles
1. Blood Typing
f. Sex Linked Traits
Learning Targets- students will be able to show mastery of identified Critical Learning Standard through the
following:
1. I can explain the phases of meiosis, as well as explain how meiosis creates haploid cells.
2. I can explain a simple dominance genetics problem using the Punnett square method.
3. I can explain the difference between genotype and phenotype.
4. I can explain the difference incomplete dominance and simple dominance.
5. I can explain the importance of a pedigree, as well as identify an individual’s genotype and
phenotype based on analysis of the pedigree.
6. I can complete multiple allele problems using the human blood typing as an example.
7. I can complete sex linked genetic problems using both Punnett squares and pedigrees.
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Objectives
Book
Ch.
Target
Meiosis
11-4
1
Simple
Dominance
Incomplete
Dominance
vs.
Simple
Dominance
11-1
&
11-2
2 and 3
11-3
4
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Date _______________ Per. 1 2 3 4 5 6 7 8
Formative
Assessment #1
 Everything I want to
Know about Meiosis
 2 CN
 2 CN
 Writing Genotypes for
Dominant and
Recessive Alleles
 Lab: Determination of
Genotypes &
Phenotypes in Human
Traits
 Lab: Create a Kid
 Incomplete Dominance
Practice Problems
Formative
Assessment #2
 Quiz #1*
 Quiz #2*
 Quiz #3*
Pedigrees
14-1
5
Multiple
Alleles
11-3
6
Quiz
Score
Reinforcement
Activity
 Practice
Problems
(remediation
packet)
 Practice
Problems
(remediation
packet)
 Pedigree Practice
Problems
 Pedigree Activity on
CF
 Blood Type Lab
 Multiple Allele
Practice Problems
 Sex Linkage Practice
Sex Linked
14-2
7
Problems
Traits
*Remediation required if you do not meet a 70% on Formative Assessment.
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THE BLUE PEOPLE OF TROUBLESOME CREEK
The story of an Appalachian malady, an inquisitive doctor, and a paradoxical cure.
by Cathy Trost
©Science 82, November, 1982
Six generations after a French orphan named Martin Fugate settled on the banks of eastern Kentucky's
Troublesome Creek with his redheaded American bride, his great-great-great great grandson was born in a
modern hospital not far from where the creek still runs.
The boy inherited his father's lankiness and his mother's slightly nasal way of speaking.
What he got from Martin Fugate was dark blue skin. "It was almost purple," his father recalls.
Doctors were so astonished by the color of Benjy Stacy's skin that they raced him by ambulance from the
maternity ward in the hospital near Hazard to a medical clinic in Lexington. Two days of tests produced no
explanation for skin the color of a bruised plum.
A transfusion was being prepared when Benjy's grandmother spoke up. "Have you ever heard of the blue
Fugates of Troublesome Creek?" she asked the doctors.
"My grandmother Luna on my dad's side was a blue Fugate. It was real bad in her," Alva Stacy, the boy's father,
explained. "The doctors finally came to the conclusion that Benjy's color was due to blood inherited from
generations back."
Benjy lost his blue tint within a few weeks, and now he is about as normal looking a seven-year-old boy as you
could hope to find. His lips and fingernails still turn a shade of purple-blue when he gets cold or angry a quirk
that so intrigued medical students after Benjy's birth that they would crowd around the baby and try to make
him cry. "Benjy was a pretty big item in the hospital," his mother says with a grin.
Dark blue lips and fingernails are the only traces of Martin Fugate's legacy left in the boy; that, and the
recessive gene that has shaded many of the Fugates and their kin blue for the past 162 years.
They're known simply as the "blue people" in the hills and hollows around Troublesome and Ball Creeks. Most
lived to their 80s and 90s without serious illness associated with the skin discoloration. For some, though, there
was a pain not seen in lab tests. That was the pain of being blue in a world that is mostly shades of white to
black.
There was always speculation in the hollows about what made the blue people blue: heart disease, a lung
disorder, the possibility proposed by one old-timer that "their blood is just a little closer to their skin." But no
one knew for sure, and doctors rarely paid visits to the remote creekside settlements where most of the "blue
Fugates" lived until well into the 1950s. By the time a young hematologist from the University of Kentucky
came down to Troublesome Creek in the 1960s to cure the blue people, Martin Fugate's descendants had
multiplied their recessive genes all over the Cumberland Plateau.
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Madison Cawein began hearing rumors about the blue people when he went to work at the
University of Kentucky's Lexington medical clinic in 1960. "I'm a hematologist, so something
like that perks up my ears," Cawein says, sipping on whiskey sours and letting his mind slip
back to the summer he spent "tromping around the hills looking for blue people."
Cawein is no stranger to eccentricities of the body. He helped isolate an antidote for cholera, and he did some of
the early work on L-dopa, the drug for Parkinson's disease. But his first love, which he developed as an Army
medical technician in World War II, was hematology. "Blood cells always looked so beautiful to me," he says.
Cawein would drive back and forth between Lexington and Hazard an eight-hour ordeal before the tollway was
built and scour the hills looking for the blue people he'd heard rumors about. The American Heart Association
had a clinic in Hazard, and it was there that Cawein met "a great big nurse" who offered to help.
Her name was Ruth Pendergrass, and she had been trying to stir up medical interest in the blue people ever
since a dark blue woman walked into the county health department one bitterly cold afternoon and asked for a
blood test.
"She had been out in the cold and she was just blue!" recalls Pendergrass, who is now 69 and retired from
nursing. "Her face and her fingernails were almost indigo blue. It like to scared me to death! She looked like she
was having a heart attack. I just knew that patient was going to die right there in the health department, but she
wasn't a'tall alarmed. She told me that her family was the blue Combses who lived up on Ball Creek. She was a
sister to one of the Fugate women." About this same time, another of the blue Combses, named Luke, had taken
his sick wife up to the clinic at Lexington. One look at Luke was enough to "get those doctors down here in a
hurry," says Pendergrass, who joined Cawein to look for more blue people.
Trudging up and down the hollows, fending off "the two mean dogs that everyone had in their front yard," the
doctor and the nurse would spot someone at the top of a hill who looked blue and take off in wild pursuit. By
the time they'd get to the top, the person would be gone. Finally, one day when the frustrated doctor was idling
inside the Hazard clinic, Patrick and Rachel Ritchie walked in.
"They were bluer'n hell," Cawein says. "Well, as you can imagine, I really examined them. After concluding
that there was no evidence of heart disease, I said 'Aha!' I started asking them questions: 'Do you have any
relatives who are blue?' then I sat down and we began to chart the family."
Cawein remembers the pain that showed on the Ritchie brother's and sister's faces. "They were really
embarrassed about being blue," he said. "Patrick was all hunched down in the hall. Rachel was leaning against
the wall. They wouldn't come into the waiting room. You could tell how much it bothered them to be blue."
After ruling out heart and lung diseases, the doctor suspected methemoglobinemia, a rare hereditary blood
disorder that results from excess levels of methemoglobin in the blood. Methemoglobin which is blue, is a
nonfunctional form of the red hemoglobin that carries oxygen. It is the color of oxygen-depleted blood seen in
the blue veins just below the skin.
If the blue people did have methemoglobinemia, the next step was to find out the cause. It can be brought on by
several things: abnormal hemoglobin formation, an enzyme deficiency, and taking too much of certain drugs,
including vitamin K, which is essential for blood clotting and is abundant in pork liver and vegetable oil.
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Cawein drew "lots of blood" from the Ritchies and hurried back to his lab. He tested first for abnormal
hemoglobin, but the results were negative.
Stumped, the doctor turned to the medical literature for a clue. He found references to methemoglobinemia
dating to the turn of the century, but it wasn't until he came across E. M. Scott's 1960 report in the Journal of
Clinical Investigation (vol. 39, 1960) that the answer began to emerge.
Scott was a Public Health Service doctor at the Arctic Health Research Center in Anchorage who had
discovered hereditary methemoglobinemia among Alaskan Eskimos and Indians. It was caused, Scott
speculated, by an absence of the enzyme diaphorase from their red blood cells. In normal people hemoglobin is
converted to methemoglobin at a very slow rate. If this conversion continued, all the body's hemoglobin would
eventually be rendered useless. Normally diaphorase converts methemoglobin back to hemoglobin. Scott also
concluded that the condition was inherited as a simple recessive trait. In other words, to get the disorder, a
person would have to inherit two genes for it, one from each parent. Somebody with only one gene would not
have the condition but could pass the gene to a child.
Scott's Alaskans seemed to match Cawein's blue people. If the condition were inherited as a recessive trait, it
would appear most often in an inbred line.
Cawein needed fresh blood to do an enzyme assay. He had to drive eight hours back to Hazard to search out the
Ritchies, who lived in a tapped-out mining town called Hardburly. They took the doctor to see their uncle, who
was blue, too. While in the hills, Cawein drove over to see Zach (Big Man) Fugate, the 76-year-old patriarch of
the clan on Troublesome Creek. His car gave out on the dirt road to Zach's house, and the doctor had to borrow
a Jeep from a filling station.
Zach took the doctor even farther up Copperhead Hollow to see his Aunt Bessie Fugate, who was blue. Bessie
had an iron pot of clothes boiling in her front yard, but she graciously allowed the doctor to draw some of her
blood.
"So I brought back the new blood and set up my enzyme assay," Cawein continued. "And by God, they didn't
have the enzyme diaphorase. I looked at other enzymes and nothing was wrong with them. So I knew we had
the defect defined.''
Just like the Alaskans, their blood had accumulated so much of the blue molecule that it over- whelmed the red
of normal hcmoglobin that shows through as pink in the skin of most Caucasians.
Once he had the enzyme deficiency isolated, methylene blue sprang to Cawein's mind as the "perfectly obvious"
antidote. Some of the blue people thought the doctor was slightly addled for suggesting that a blue dye could
turn them pink. But Cawein knew from earlier studies that the body has an alternative method of converting
methemoglobin back to normal. Activating it requires adding to the blood a substance that acts as an "electron
donor." Many substances do this, but Cawein chose methylene blue because it had been used successfully and
safely in other cases and because it acts quickly.
Cawein packed his black bag and rounded up Nurse Pendergrass for the big event. They went over to Patrick
and Rachel Ritchie's house and injected each of them with 100 milligrams of methylene blue.
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''Within a few minutes. the blue color was gone from their skin," the doctor said. "For
the first time in their lives, they were pink. They were delighted."
"They changed colors!" remembered Pendergrass. "It was really something exciting to
see."
The doctor gave each blue family a supply of methylene blue tablets to take as a daily
pill. The drug's effects are temporary, as methylene blue is normally excreted in the urine. One day, one of the
older mountain men cornered the doctor. "I can see that old blue running out of my skin," he confided.
Before Cawein ended his study of the blue people, he returned to the mountains to patch together the long and
twisted journey of Martin Fugate's recessive gene. From a history of Perry County and some Fugate family
Bibles listing ancestors, Cawein has constructed a fairly complete story.
Martin Fugate was a French orphan who emigrated to Kentucky in 1820 to claim a land grant on the wilderness
banks of Troublesome Creek. No mention of his skin color is made in the early histories of the area, but family
lore has it that Martin himself was blue.
The odds against it were incalculable, but Martin Fugate managed to find and marry a woman who carried the
same recessive gene. Elizabeth Smith, apparently, was as pale-skinned as the mountain laurel that blooms every
spring around the creek hollows.
Martin and Elizabeth set up housekeeping on the banks of Troublesome and began a family. Of their seven
children, four were reported to be blue.
The clan kept multiplying. Fugates married other Fugates. Sometimes they married first cousins. And they
married the people who lived closest to them, the Combses, Smiths, Ritchies, and Stacys. All lived in isolation
from the world, bunched in log cabins up and down the hollows, and so it was only natural that a boy married
the girl next door, even if she had the same last name.
"When they settled this country back then, there was no roads. It was hard to get out, so they intermarried," says
Dennis Stacy, a 51-year-old coal miner and amateur genealogist who has filled a loose-leaf notebook with the
laboriously traced blood lines of several local families.
Stacy counts Fugate blood in his own veins. "If you'll notice," he observes, tracing lines on his family's chart,
which lists his mother's and his father's great grandfather as Henley Fugate, "I'm kin to myself."
The railroad didn't come through eastern Kentucky until the coal mines were developed around 1912, and it
took another 30 or 40 years to lay down roads along the local creeks.
Martin and Elizabeth Fugate's blue children multiplied in this natural isolation tank. The marriage of one of
their blue boys, Zachariah, to his mother's sister triggered the line of succession that would result in the birth,
more than 100 years later, of Benjy Stacy.
When Benjy was born with purple skin, his relatives told the perplexed doctors about his great grandmother
Luna Fugate. One relative describes her as "blue all over," and another calls Luna "the bluest woman I ever
saw."
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Luna's father, Levy Fugate, was one of Zachariah Fugate's sons. Levy married a Ritchie girl and bought 200
acres of rolling land along Ball Creek. The couple had eight children, including Luna.
A fellow by the name of John E. Stacy spotted Luna at Sunday services of the Old Regular Baptist Church back
before the century turned. Stacy courted her, married her, and moved over from Troublesome Creek to make a
living in timber on her daddy's land.
Luna has been dead nearly 20 years now, but her widower survives. John Stacy still lives on Lick Branch of
Ball Creek. His two room log cabin sits in the middle of Laurel Fork Hollow. Luna is buried at the top of the
hollow. Stacy's son has built a modern house next door, but the old logger won't hear of leaving the cabin he
built with timber he personally cut and hewed for Luna and their 13 children.
Stacy recalls that his father-inlaw, Levy Fugate, was "part of the family that showed blue. All them old fellers
way back then was blue. One of 'em I remember seeing him when I was just a boy Blue Anze, they called him.
Most of them old people went by that name the blue Fugates. It run in that generation who lived up and down
Ball [Creek]."
"They looked like anybody else, 'cept they had the blue color," Stacy says, sitting in a chair in his plaid flannel
shirt and suspenders, next to a cardboard box where a small black piglet, kept as a pet, is squealing for his
bottle. "I couldn't tell you what caused it."
The only thing Stacy can't or won't remember is that his wife Luna was blue. When asked ahout it, he shakes his
head and stares steadfastly ahead. It would be hard to doubt this gracious man except that you can't find another
person who knew Luna who doesn't remember her as being blue.
"The bluest Fugates I ever saw was Luna and her kin," says Carrie Lee Kilburn, a nurse who works at the rural
medical center called Homeplace Clinic. "Luna was bluish all over. Her lips were as dark as a bruise. She was
as blue a woman as I ever saw."
Luna Stacy possessed the good health common to the blue people, bearing at least 13 children before she died at
84. The clinic doctors only saw her a few times in her life and never for anything serious.
As coal mining and the railroads brought progress to Kentucky, the blue Fugates started moving out of their
communities and marrying other people. The strain of inherited blue began to disappear as the recessive gene
spread to families where it was unlikely to be paired with a similar gene.
Benjy Stacy is one of the last of the blue Fugates. With Fugate blood on both his mother's and his father's side,
the boy could have received genes for the enzyme deficiency from either direction. Because the boy was
intensely blue at birth but then recovered his normal skin tones, Benjy is assumed to have inherited only one
gene for the condition. Such people tend to be very blue only at birth, probably because newborns normally
have smaller amounts of diaphorase. The enzyme eventually builds to normal levels in most children and to
almost normal levels in those like Benjy, who carry one gene.
Hilda Stacy (nee Godsey) is fiercely protective of her son. She gets upset at all the talk of inbreeding among the
Fugates. One of the supermarket tabloids once sent a reporter to find out about the blue people, and she was
distressed with his preoccupation with intermarriages.
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She and her husband Alva have a strong sense of family. They sing in the Stacy Family Gospel Band and have
provided their children with a beautiful home and a menagerie of pets, including horses.
"Everyone around here knows about the blue Fugates," says Hilda Stacy who, at 26, looks more like a sister
than a mother to her children. "It's common. It's nothing.''
Cawein and his colleagues published their research on hereditary diaphorase deficiency in the Archives of
Internal Medicine (April, 1964) in 1964. He hasn't studied the condition for years. Even so, Cawein still gets
calls for advice. One came from a blue Fugate who'd joined the Army and been sent to Panama, where his son
was born bright blue. Cawein advised giving the child methylene blue and not worrying about it. Note: In this
instance the reason for cyanosis was not methemoglobinemia but Rh incompatibility. This information supplied by John Graves whose
uncle was the father of the child.
The doctor was recently approached by the producers of the television show "That's Incredible." They wanted to
parade the blue people across the screen in their weekly display of human oddities. Cawein would have no part
of it, and he related with glee the news that a film crew sent to Kentucky from Hollywood fled the "two mean
dogs in every front yard" without any film. Cawein cheers their bad luck not out of malice but out of a deep
respect for the blue people of Troublesome Creek.
"They were poor people," concurs Nurse Pendergrass, "but they were good."
References
1. Cawein, Madison, et. al. "Hereditary diaphorase deficiency and methemoglobinemia". Archives of
Internal Medicine, April, 1964.
2. Scott, E.M. "The relation of diaphorase of human erythrocytes to inheritance of methemolglobinemia",
Journal of Clinical Investigation, 39, 1960.
3. Cawein, Madison and E.J. Lappat, "Hereditary Methemoglobinemia" in Hemoglobin, Its Precursors and
Metabolites, ed. by F. William Sunderman, J.B. Lippincott Co., Philadelphia PA, 1964.
Eleanor and Lorenzo Fugate
Family Pedigree
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The Blue People of Troublesome Creek
Directions: Please write all answers in complete sentences.
1. Who was the first blue person to settle in Kentucky’s Troublesome Creek?
2. How many generations ago did he settle there?
3. What enzyme was missing in their blood?
4. What does this enzyme do in the body?
5. Martin Fugate and his wife had seven children. How many were reported to be blue?
6. How do they account for so many blue people occurring in the Troublesome Creek area?
7. What was the drug given to the Blue Fugates that turned them pink?
8. How many genes did Benjy carry?
9. What does Nurse Pendergrass have to say about the blue people of Troublesome Creek?
10. Is the trait for the blue skin a dominant or recessive gene?
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Date _______________ Per. 1 2 3 4 5 6 7 8
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I Want To Know Everything About Meiosis Worksheet
Directions: Use your PPT notes and Chapter 11.4 in your textbook on Meiosis to fill in the following data table in detail.
Please start off with an immature sex cell that contains 4 chromosomes as its diploid (2n) number. In your drawings,
include and label ALL structures associated with the specific phase of meiosis. To get you started, some structures to
include are: chromatin, chromosomes, cell membrane, nucleus, nucleolus, centrioles, spindle fibers, centromeres, sister
chromatids, chromatids, cytoplasm, nucleoplasm and nuclear membrane. Please include and label other structures
important to the phases of meiosis.
Phase of Meiosis
True Picture
(labeled organelles/ meiotic structures)
List the events that take place
(make a bulleted list)
Interphase
Prophase I
Metaphase I
Anaphase I
Telophase I
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Prophase II
Metaphase II
Anaphase II
Telophase II
Cytokinesis
Describe the main events of meiosis.
__________________________________________________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________
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Chapter _____ Pages ___________
Section or Chapter Title: ______________________
Pre-Reading: Predicting and Inferring
Write THREE SENTENCES that come to mind about the topic:



What is one question you have about the topic that you think will be answered in the reading:

During-Reading:
Key Ideas and Section Heading
Supporting Details (use graphics & pictures as well as text) –
pictures should have meaningful color used
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Key Ideas and Section Heading
Name_______________________________________
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Supporting Details (use graphics & pictures as well as text) –
pictures should have meaningful color used
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Vocabulary Word
Definition (in your own words)
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Picture (with meaningful color
used)
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After Reading: Summarizing
Write a FOUR sentence summary about the reading:
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Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
WRITING KEYS FOR GENOTYPES
Genetic traits are represented in problems with letter symbols. The symbols tell us something about the way the
trait is inherited and how it shows up in offspring. This worksheet will help you to correctly write genetic
symbols. A key helps us to understand the genotype for an organism.
Instructions: A dominant allele is always given a capital letter. The recessive form of an allele is lower case,
but the same letter is used. Two letters are used to write the genotype for a trait. The dominant trait is
usually underlined in a problem. Remember, the genotype represents the alleles present on a pair of
chromosomes: One from each parent organism. That’s why it contains two letters.
Ex. Purple flowers are dominant to white ones in pea plants.
Key: P = purple,
p = white
Write a key for each of the following dominant/recessive allele pairs:
1. There are two common colors of peas; yellow and green.
2. Round peas are dominant to wrinkled ones.
3. Inflated pea pods are dominant to constricted ones.
4. The allele for tall pea plants in dominant to dwarf ones.
5. The color green is dominant to yellow for pea pod color.
6. Black coat color is dominant to white in mice.
7. Widow’s peak hairline is dominant to non-widow’s peak.
8. Free earlobes is dominant to attached earlobes.
9. Tongue rolling is dominant to non-rolling in humans.
10. 11. In humans, the allele for having extra fingers or toes is dominant to the normal number of 5.
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Genetics Vocabulary Practice
CAPITAL letters represent dominant genes.
LOWERCASE letters represent recessive genes.
There are at least 2 genes, therefore 2 letters, for each trait or feature
B = brown eyes
b = no brown eyes
F = freckles
f = no freckles
R = red flower
r = white flower
T = tall plants
t = short plants
G = gray fur
g = albino (white)
L = long tail
l = short tail
Use the above letters to write the correct combinations of genes (genotypes) for each of the following
traits. Hybrid is the same as heterozygous. Pure is the same as homozygous.
1. hybrid tall plant _________
2. pure long tailed _________
3. pure white flowers _________
4. hybrid freckles _________
5. hybrid gray
_________
6. pure short _________
7. pure albino _________
8. hybrid brown _________
9. pure no freckles _________
10. heterozygous freckles _________
What will each of the following gene combinations look like (phenotypes)?
TT
Rr
Ll
Gg
BB
gg
GG
______________________
______________________
______________________
______________________
______________________
______________________
______________________
Tt ______________________
RR ______________________
ll ______________________
Ff ______________________
bb ______________________
Bb ______________________
rr ______________________
Circle the ones that are NOT pure (homozygous):
AA
Aa
bb
CC
Cc
Gg
SS
ss
Ss
tt
rr
Dd
Circle the ones that are NOT hybrid (heterozygous):
AA
Aa
BB
bb
Cc
Oo
LL
MM
TT
Hh
Ww
Ee
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Use the chart on the previous page to answer the following – answer “yes” or “no.”
1. Is it possible to have a hybrid short tail? __________________________________
2. Is it possible to have a hybrid albino? _____________________________________
3. Is it possible to have a hybrid brown? _____________________________________
4. Is it possible to have a pure albino? _______________________________________
5. Is it possible to have a pure hybrid red flower? _____________________________
In humans dark hair (D) is dominant to light hair (d). What will the following phenotypes look like?
1. dd _____________________
7. Dd
_____________________
8. DD ______________________
What 2 genes (genotype) will each feature have?
9. Hybrid dark hair __________
10. Pure light hair
____________
11. Pure dark hair _____________
12. Light hair ____________
If the father has pure dark hair and the mother pure light hair . . .
13. What kind of genes does the father have? __________
14. What kind of genes does the mother have? __________
15. What kind of genes will their children have? __________
16. Is it possible for any one of their children to have light hair? __________
If the father is hybrid dark and the mother is light . . .
17. What kind of genes does the father have? _________
18. What kind of genes does the mother have? _________
19. What possible combinations of genes will their children have? (2 possibilities) _____ ______
If both parents are hybrid. . .
20. What kinds of genes does the father have? ___________
21. What kinds of genes does the mother have? ___________
22. What is the color of the hair of the parents? __________
23. What possible combinations of genes will their kids have? (3 possibilities) _____ _____ _____
24. Is it possible to have kids with both dark and light hair? ________
25. What are the chances of a child having light hair? _________
If some of the offspring have dark hair and some light hair . . .
26. Is it possible that both parents have light hair? _______
27. Is it possible that both parents have dark hair? _______
28. If so, are the parents pure or hybrid? _________
29. Is it possible that one parent have dark hair and one parent be light? _________
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PRACTICE WRITING GENOTYPES FOR DOMINANT & RECESSIVE ALLELES
First, define the following terms. These terms are extremely important in genetics.
Allele
_________________________________________________________________________
Phenotype _________________________________________________________________________
Genotype _________________________________________________________________________
Homozygous ________________________________________________________________________
Heterozygous ________________________________________________________________________
NOTE: Two letters are always used to represent the two alleles that an organism has for each trait.
Homozygous dominant = Two of the same capital letters
Homozygous recessive = Two of the same lower case letters
Heterozygous
= One capital and one lower case letter
Ex. AA
Ex. aa
Ex. Aa
INSTRUCTIONS: Write a key, phenotype, and genotype for each animal or plant. The dominant trait
is underlined.
1. A homozygous black guinea pig. (White coat is recessive to black.)
Key = __________________________
Phenotype = _______________________
Genotype = _________
2. A heterozygous black guinea pig. (Use same key as in #1.)
Phenotype = _______________________
Genotype = _________
3. A white guinea pig. (Use same key as in #1.)
Phenotype = _______________________
Genotype = _________
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4. A homozygous purple-flowered pea plant. (White is recessive to purple.)
Key = ___________________________
Phenotype = _______________________
Genotype = _________
5. A heterozygous purple-flowered pea plant. (Use same key as in #4.)
Phenotype = _______________________
Genotype = _________
6. A white-flowered pea plant. (Use same key as in #4.)
Phenotype = _______________________
Genotype = _________
7. A woman who is homozygous for tongue rolling. (Non-rolling is recessive.)
Key = ___________________________
Phenotype = _______________________
Genotype = _________
8. A man who is heterozygous for tongue rolling. (Use same key as in #7.)
Phenotype = _______________________
Genotype = _________
9. A child who is unable to roll his tongue (non-roller). (Use same key as in #7.)
Phenotype = _______________________
Genotype = _________
10. Cystic fibrosis is a fatal, recessive genetic disease that affects the ability to properly breathe. The normal
condition is dominant. Write a key and genotype for a child with cystic fibrosis.
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Punnett Square Exercise
Steps to Solving Genetics Problems:
1. What genetic relationship is shown? (i.e. complete dominance, incomplete dominance, codominance,
multiple alleles, sex-linked, etc.)
2. Write a key. (Dominant traits are underlined.)
3. Write the cross.
4. Show the Punnett square/ FOIL method.
5. Answer the question(s) and circle.
Practice Problems: Complete all steps for each problem.
1. Cross a heterozygous brown guinea pig with a white one. State the phenotypes and the probabilities for
F1. Also state the genotypes and the probabilities.
2. Cross a homozygous curly haired male with a straight haired female. State the phenotypes and the
probabilities for F1. Also state the genotypes and the probabilities.
3. What is the probability of having a child with straight hair? (Use information from #2).
4. Cross a heterozygous freckled female with a homozygous recessive male. State all the phenotypes and
genotypes resulting from this cross. Also state the probability of having a child with freckles?
5. Cross a heterozygous brown eyed male with a heterozygous brown eyed female. Blue is recessive to
brown eye color. State the genotypic and phenotypic ratios. Also, what is the probability of having a
child with blue eyes?
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Single Trait (Monohybrid) Problems
Steps to Solving Genetics Problems:
1. What genetic relationship is shown? (i.e. complete dominance, incomplete dominance, codominance,
multiple alleles, sex-linked, etc.)
2. Write a key. (Dominant traits are underlined.)
3. Write the cross.
4. Show the Punnett square/ FOIL method.
5. Answer the question(s) and circle.
Practice Problems: Complete all steps for each problem.
1. Cross a homozygous black guinea big with a brown one. State the phenotypes and the probability for
the F1.
2. Cross a man heterozygous for dimples with a woman lacking dimples. State the phenotypes and
probability of each for their children (the F1 generation).
3. Cross a pure (homozygous) short-haired guinea pig with a long-haired guinea pig. What is the
probability of getting long-haired offspring in the F1 generation?
4. Cross a heterozygous yellow pea plant with a green pea plant. What is the probability of getting green
offspring in the F1?
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5. Cross a heterozygous black mare with a heterozygous black stallion. (Chestnut is recessive.) What is
the probability of getting chestnut offspring?
6. A man and wife are known to both be heterozygous for curly hair, a trait dominant to straight hair.
What is the probability that they will have a child with straight hair?
7. Cross a homozygous rough-coated guinea pig with a smooth coated guinea pig. State the phenotypes
and their probabilities for both the F1 and F2 generations.
8. In humans, tongue-rolling is dominant over non-tongue rolling. If a man is a non-tongue roller and his
wife is heterozygous for tongue rolling, predict the phenotypes and their probabilities for their children.
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Single Trait (Autosomal Recessive) Problems 2
Steps to Solving Genetics Problems:
1. What genetic relationship is shown? (i.e. complete dominance, incomplete dominance, codominance,
multiple alleles, sex-linked, etc.)
2. Write a key. (Dominant traits are underlined.)
3. Write the cross.
4. Show the Punnett square/ FOIL method.
5. Answer the question(s) and circle.
Practice Problems: Complete all steps for each problem.
How can two healthy parents produce a child with a genetic disorder? This question can be an agonizing one for
parents who find themselves in such a situation. An understanding of genetics can help explain how this
happens and remove some of the unnecessary guilt they may feel.
Friederich’s ataxia is a hereditary disorder characterized by deformity of the feet, degeneration of the spinal
cord, and an early death (usually before the age of thirty). It is caused by a recessive gene which we designate
as n.
1. Suppose that two parents, the father is homozygous for F, while the mother is heterozygous for this trait.
What are the chances that one of the children of this mating will develop Friederich’s ataxia?
2. Now suppose that both father and mother are heterozygous for this trait. What are the chances that the
first child of this mating will develop the disease? What are the chances that the second, third and fourth
children will develop the disease?
3. Suppose that a child is born with Friederich’s ataxia. What can you say about the genotypes and
phenotypes of the child’s parents?
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Introduction
Heredity is the passing on the traits, or characteristics, from parent to offspring. The genetic makeup of
an individual is known as genotype. The physical traits you can observe in a person are his or her phenotype.
Phenotype is a result of the genotype and the environment.
The units of heredity are called genes. Genes are found on the chromosomes in a cell. An allele is one
of two or more forms of a gene. When the two alleles of a pair are the same, the genotype is homozygous, or
pure. When the two alleles are not the same, the genotype is heterozygous, or hybrid. Specific combinations of
alleles only happen by chance.
Some alleles are expressed only when the genotype is homozygous. These alleles produce recessive
phenotypes. Alleles that are expressed when they are homozygous and heterozygous produce dominant
phenotypes. An allele that codes for a dominant trait is represented by a capital letter, while an allele that codes
for a recessive trait is represented by a lowercase letter.
In humans, the sex of a person is determined by the combination of two sex chromosomes. People who
have two X chromosomes (XX) are females, while those who have one X and one Y chromosome (XY) are
males.
In this investigation, you will see how different combinations of alleles produce different characteristics.
Problem
To demonstrate the principles of Mendelian genetics and sex determination, including the concepts of
allele, phenotype, genotype, dominant, recessive, homozygous and heterozygous by creating a simulated kid.
Pre-Lab Discussion
1. Why is the coin flip used to represent the selection of alleles?
2. What is heredity?
____________________________________________________________________________________
____________________________________________________________________________________
3. Define the following vocabulary terms:
a. Allele ________________________________________________________________________
______________________________________________________________________________
b. Phenotype _____________________________________________________________________
______________________________________________________________________________
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c. Genotype _____________________________________________________________________
______________________________________________________________________________
d. Dominant _____________________________________________________________________
______________________________________________________________________________
e. Recessive _____________________________________________________________________
______________________________________________________________________________
f. Homozygous __________________________________________________________________
______________________________________________________________________________
g. Heterozygous __________________________________________________________________
______________________________________________________________________________
h. Chromosome __________________________________________________________________
______________________________________________________________________________
i. Gene _________________________________________________________________________
______________________________________________________________________________
Materials: (per pair)
 2 Coins
Procedure:
1. Determine which partner will toss for the female and which will toss for the male. Remember that there
are two genes per trait.
2. Have the partner who is representing the male (dad) flip a coin to determine the sex of the offspring. If
the coin lands heads up, the gene passed is X, and your kid will be female. If the coin lands tails up, the
gene passes is Y, and your kid will be male. Record the sex of your kid in your data table.
3. For all the coin tosses you will now make, heads will represent the dominant allele (capital letter) and
tails will represent the recessive allele (lower case letter).
4. You and your partner should now flip your coins at the same time to determine the phenotype of the rest
of the traits on the data table. After each flip, record the gene passed from the mom and dad, as well as
the genotype and phenotype of your kid.
Note: The coins should be flipped only once for each trait.
5. Now the fun part…Draw a picture of the facial features of your kid! Use the recorded traits to help
determine what each trait should look like.
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Data Table:
Trait
Sex of Kid
Gene from Mom
Gene from Dad
Genotype and Phenotype of Kid
X
Shape of face (R or r)
Cleft of chin (C or c)
Texture of hair (H or h)
Widow’s peak (W or w)
Spacing of eyes (E or e)
Shape of eyes (A or a)
Position of eyes (S or s)
Size of eyes (L or l)
Length of eyelashes (L or l)
Shape of eyebrows (B or b)
Position of eyebrows (N or n)
Size of nose (L or l)
Shape of lips (T or t)
Size of ears (L or l)
Size of mouth (L or l)
Freckles (F or f)
Dimples (D or d)
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Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Names of Parents: __________________________ and __________________________
Sex of Child: __________________________
Name of Child: __________________________
Draw a picture of the face of your kid using all of the characteristics that were determined in this lab. Label the
genotypes for all the trails that are included.
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Analysis and Conclusion
1. Calculating: What percent chance did you and your partner have of “producing” a male offspring? A
female offspring? Explain your answer.
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
2. Predicting: Would you expect the other pairs of students in your class to have an offspring similar to
yours? Explain your answer.
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
3. Inferring: What are the possible genotypes of the parents of a child who has wavy hair (Cc)?
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
4. Drawing Conclusions: Do you think that anyone in your class has all the same genetic traits that you
have? Explain your answer.
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
5. Drawing Conclusions: How might it be possible for you to show a trait when none of your relatives
shows it?
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
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Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Chapter ___________ Pages___________________
Section or Chapter Title: ______________________
Pre-Reading: Predicting and Inferring
Write THREE SENTENCES that come to mind about the topic:



What is one question you have about the topic that you think will be answered in the reading:

During-Reading:
Key Ideas and Section Heading
Supporting Details (use graphics & pictures as well as text) –
pictures should have meaningful color used
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Biology S137
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Key Ideas and Section Heading
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Supporting Details (use graphics & pictures as well as text) –
pictures should have meaningful color used
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Biology S137
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Vocabulary Word
Definition (in your own words)
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Picture (with meaningful color
used)
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Biology S137
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Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
After Reading: Summarizing
Write a FOUR sentence summary about the reading:
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Biology S137
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Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Incomplete Dominance
Introduction:
Some genes don’t show dominant/recessive phenotypes. When two different alleles for a trait are present in an
individual, the individual will show a blending of the two traits. This “blending” is called incomplete
dominance. Therefore, each genotype has its own phenotype and no allele can be hidden by another allele.
Steps to Solving Genetics Problems:
1. What genetic relationship is shown? (i.e. complete dominance, incomplete dominance, codominance,
multiple alleles, sex-linked, etc.)
2. Write a key.
3. Write the cross.
4. Show the Punnett square/ FOIL method.
5. Answer the question and circle.
Practice Problems: Complete all steps for each problem.
1. Red snapdragons have the genotype RR and white ones have the genotype rr. When pure breeding red
and white snapdragons are crossed, the offspring are all pink. Set up a Punnett square or use FOIL
method for this cross showing the F1 generation. Show the phenotypes, genotypes and their
probabilities for the F1 generation.
2. Cross two pink snapdragons. Offspring from this cross represent the F2 generation. Show the
phenotypes, genotypes and their probabilities for the F2 generation.
3. Write a general concluding statement that sums up incomplete dominance.
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Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Incomplete Dominance 2
In some cases, one allele is not completely dominant over the other allele. Instead, the genes seem to “blend”
together. This is called incomplete dominance.
Steps to Solving Genetics Problems:
1. What genetic relationship is shown? (i.e. complete dominance, incomplete dominance, codominance,
multiple alleles, sex-linked, etc.)
2. Write a key.
3. Write the cross.
4. Show the Punnett square/ FOIL method.
5. Answer the question and circle.
Practice Problems: Complete all steps for each problem.
1. In cattle, the gene for red coat color, R, is incompletely dominant to the gene for white coat color, r. The
heterozygous condition results in roan colored cattle. A red bull is crossed with a white cow. Show the
genotypic and phenotypic ratios of the offspring.
2. Cross a roan bull with a roan cow. Show the genotypic and phenotypic ratios of the offspring.
3. In guinea pigs, the gene for yellow coat color is incompletely dominant to the gene for white coat color.
The heterozygous condition results in cream-colored guinea pigs. Cross a cream-colored guinea pig
with a white colored one. Show the genotypic and phenotypic ratios of the offspring.
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Date _______________ Per. 1 2 3 4 5 6 7 8
4. In four o’clocks (flowers), the gene for red flowers, R, is incompletely dominant to the gene for white
flowers, r. The heterozygous condition results in pink flowers.
a. A gardener crosses two red four o’clocks. What are the expected genotypic and phenotypic
ratios among the offspring?
b. What are the expected genotypes and phenotypes resulting from crossing two pink four
o’clocks?
c. Why is it impossible to develop a strain of pure of breeding four o’clocks?
5. In Andalusian Fowl (a breed of bird), the gene for black plumage , B, is incompletely dominant to the
gene for white plumage, b. The heterozygotes have blue plumage. List the genotypic and phenotypic
ratios expected from crossing:
a. Black x Blue
b. Blue X Blue
c. Blue X White
d. Black X White
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Codominance
Example: MN Blood Group
Example: MN Blood Group
Mendel’s original work seemed to show that there were two types of genes: dominant and recessive. We have
learned that this description is overly simple. There are also cases when both alleles of a homologous pair are
expressed in the offspring. A case of this kind is referred to as codominance.
An example of codominance is found in the MN blood group in humans. The two alleles for this blood group,
M and N are codominant, with MM producing type M blood, NN producing type N, and MN producing type
MN.
Steps to Solving Genetics Problems:
1. What genetic relationship is shown? (i.e. complete dominance, incomplete dominance, codominance,
multiple alleles, sex-linked, etc.)
2. Write a key.
3. Write the cross.
4. Show the Punnett square/ FOIL method.
5. Answer the question and circle.
Practice Problems: Complete all steps for each problem.
1. Suppose that a person who is homozygous for the M blood type marries a person who is homozygous
for the N type. Show the phenotypic and genotypic ratios of the F1 generation.
2. Now show the phenotypic and genotypic ratios of the F2 generation.
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Date _______________ Per. 1 2 3 4 5 6 7 8
Codominance
Example: Sickle Cell Anemia
The genetic disease “sickle-cell anemia,” in humans, is caused by two codominant alleles. Two normal genes
(NN) produce normal red blood cells. Two sickle cell genes (SS) cause the disease to occur. Individuals
afflicted with this disease have “sickled” red blood cells that are unable to carry oxygen properly. The
heterozygous (NS) is not fatal and seems to offer protection against malaria infection.
Steps to Solving Genetics Problems:
1. What genetic relationship is shown? (i.e. complete dominance, incomplete dominance, codominance,
multiple alleles, sex-linked, etc.)
2. Write a key.
3. Write the cross.
4. Show the Punnett square/ FOIL method.
5. Answer the question and circle.
Practice Problems: Complete all steps for each problem.
1. If a man and women are tested and found to be carriers of the sickle allele, what is the probability that
they will have a child who has sickle-cell anemia?
2. Show a cross between a man who has sickle cell anemia and a woman who is a carrier of the trait. What
percentage of the offspring will have the trait?
3. Show a cross between a normal male and woman who has sickle cell anemia. What percentage of their
offspring will have sickle cell anemia?
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Date _______________ Per. 1 2 3 4 5 6 7 8
Codominance
Example: Thalassemmia
An anemic condition in humans called thalassemmia is controlled by codominant alleles. Homozygotes for the
defective allele (TT) have a severe anemia (thalassemmia major), whereas heterozygotes (NT) have mild
anemia (thalassemmia minor). Normal individuals are homozygous (NN) and do not have anemia.
Steps to Solving Genetics Problems:
1. What genetic relationship is shown? (i.e. complete dominance, incomplete dominance, codominance,
multiple alleles, sex-linked, etc.)
2. Write a key.
3. Write the cross.
4. Show the Punnett square/ FOIL method.
5. Answer the question and circle.
Practice Problems: Complete all steps for each problem.
1. Show a cross between a man that is homozygous for thalassemmia and a woman that does not have
anemia. What are the percentages of all phenotypes and genotypes?
2. What are the genotypic and phenotypic ratios for the F2 generation?
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Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Multiple Alleles
Example: ABO Blood Type
Multiple alleles is a condition where more than two alleles exist for the same gene. The only example we will
see in this class is human blood types. In the ABO blood group system, there are three alleles that determine
blood type. The A allele produces A markers on red blood cells. The B allele produces B markers on red blood
cells. The O allele actually does produce a marker, but we don’t test for it. It is recessive to both A and B. The
A and B alleles are codominant (equally strong) to each other. Use the following key when solving any blood
type genetics problem:




AA/AO= A blood type
BB/BO= B blood type
AB = AB blood type
OO= O blood type
A person can only possess two alleles for blood type at a time! Since the gene for blood type exists on
chromosome pair #9, you have one allele on each member of pair #9 for a total of two. These alleles may be
the same or different.
Steps to Solving Genetics Problems:
1. What genetic relationship is shown? (i.e. incomplete dominance, codominance, dominant/recessive,
multiple alleles, sex-linked, etc.)
2. Write a key.
3. Write the cross.
4. Show the Punnett square/ FOIL method.
5. Answer the question and circle.
Practice Problems: Complete all steps for each problem.
1. A man who is homozygous for type A blood marries a woman who is type O. Predict the possible
genotypes , phenotypes and their ratios for children they may have later.
2. Two parents who both have type B blood have a child who has type O blood. How is this possible?
Show your work.
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Biology S137
Andrianopoulos/Friel/McCloud/McHugh/Shoub
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
3. Show how it might be possible for a type A man and a type B woman to have a type O baby.
4. A type AB man marries a type B woman whose mother had type O blood. Show the possible genotypes,
phenotypes and their probabilities for children the couple may have.
5. Show all the possible genotypes, phenotypes and their probabilities for children of a couple who are
both type AB. What is the probability of this couple having a type O child?
6. A man who has blood type A marries a woman who has blood type O. The man’s father had blood type
O. What are the genotypic and phenotypic ratios for their children?
7. A woman with blood type AB marries a man with blood type B. The man’s mother had blood type O.
What are the possible blood types of their children? (Give percentages.)
8. A man and woman have children with the following blood types: A, B , AB and O. What are the
genotypes of the parents?
9. Can a woman with blood type A and a man with blood type O have children with AB blood? Why or
why not?
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Biology S137
Andrianopoulos/Friel/McCloud/McHugh/Shoub
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Multiple Alleles 2
Steps to Solving Genetics Problems:
1. What genetic relationship is shown? (i.e. incomplete dominance, codominance, dominant/recessive,
multiple alleles, sex-linked, etc.)
2. Write a key.
3. Write the cross.
4. Show the Punnett square/ FOIL method.
5. Answer the question and circle.
Practice Problems: Complete all steps for each problem.
1. Make the proper key and list the six possible genotypes for blood types. Then write the phenotype for
each genotype.
2. Suppose a man with blood type A, whose father was type O, marries a woman with type AB blood.
What blood types can be expected in their children? Show all work and give genotypic and phenotypic
ratios.
3. In the family represented by this pedigree, the blood types of the parents are different. Each of the four
children has a blood type that is different from the other children . Give the genotype and phenotypes
of all six individuals.
4. If a mother and child are both type O, which blood type cannot be present in the father?
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Biology S137
Andrianopoulos/Friel/McCloud/McHugh/Shoub
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
5. In 1945, in a greatly publicized trial, a California jury decided that Charles Chaplin had fathered Joan
Barry’s daughter, Carol Ann. This decision cost Chaplin about $100,000 for attorney’s fees. In
addition, the accused, Chaplin, was instructed by the judge to pay a large sum each week for the support
of Carol Ann until she reached the age of 21. Blood groups were not admissible as evidence in
California courts for cases dealing with disputed parentage at the time of the suit. However, the blood
groups of the three individuals are as follows:
Blood
Group
Charles
O
Chaplin
Joan Barry
A
Carol Ann
B
a. Do you think Charles Chaplin was the father of Carol Ann? ___________
b. Give reasons for the above answer.
c. Give the genotype of Joan Barry: __________
d. Give the possible genotypes of the father of Carol Ann: ______________
e. Give the genotype of Carol Ann: ______________
6. Suppose two newborn babies are mixed up in a hospital. From determining the blood types of the
parents and babies the problem was solved. Explain how. What was the genotype of each person?
Baby 1
Baby 2
Mrs. Brown
Mr. Brown
Mrs. Smith
Mr. Smith
Blood
Type
O
A
B
AB
B
B
Genotype
SUPER CHALLENGE
7. In mice, there are 3 alleles for coat color. The three coat colors are listed in order of dominance.
 A1 –yellow (most dominant)
 A2 –gray
 a - black
What kinds of offspring will result from the following crosses? Give genotypic and phenotypic ratios.
a. A1a XA1a
b. A1A2 X A1a
c. A2a X A1a
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Biology S137
Andrianopoulos/Friel/McCloud/McHugh/Shoub
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Problem 1: The following pedigree is for albinism. Albinism is an autosomal recessive trait.
The filled in squares and circles represent: _______________________________________
 Number the generations and people within each generation.
 Write all possible genotypes for each individual below their symbol.
 Shade individuals who are known carriers.
 Circle individuals for whom you do not have enough information to determine their true genotype.
KEY:
Problem 2: The following pedigree traces red-green colorblindness, a sex-linked recessive trait.
The filled in squares and circles represent: _______________________________________
 Number the generations and people within each generation.
 Write all possible genotypes for each individual below their symbol.
 Shade individuals who are known carriers.
Circle individuals for whom you do not have enough information to determine their true genotype.
KEY:
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Biology S137
Andrianopoulos/Friel/McCloud/McHugh/Shoub
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
MORE SEX-LINKED PEDIGREE PRACTICE. . . . . . . . .
Problem 3: The following pedigree is for red-green colorblindness.
The filled in squares and circles represent: _______________________________________
 Number the generations and people within each generation.
 Write all possible genotypes for each individual below their symbol.
 Shade individuals who are known carriers.
 Circle individuals for whom you do not have enough information to determine their true genotype.
KEY:
Problem 4: The following pedigree is for hemophilia.
The filled in squares and circles represent: _____________________________________________
 Number the generations and people within each generation.
 Write all possible genotypes for each individual below their symbol.
 Shade individuals who are known carriers.
 Circle individuals for whom you do not have enough information to determine their true genotype.
KEY:
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Biology S137
Andrianopoulos/Friel/McCloud/McHugh/Shoub
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Sex Linkage
This situation involves the sex chromosomes – pair number 23 in humans. Pair 23 in women consists of two X
chromosomes. Males have one X and one Y chromosome. Sex-linked genes are carried on the X chromosome.
In humans, sex-linked refers to X-linked. The Y-chromosome contains genes for male characteristics and
determines the sex of the individual. Hereditary illnesses such as color blindness and hemophilia are carried on
the X chromosome. Most sex-linked diseases are recessive.
Because males have an X and a Y chromosome, any recessive disease gene on the X chromosome will show
itself. A woman has two X chromosomes, and may carry (hide) a sex-linked recessive gene if her other X
chromosome is normal. A woman who is heterozygous for a sex-linked gene is termed a CARRIER. Males
cannot be carriers of sex-linked traits. They either show the trait or they don’t.
To remind ourselves that certain traits are sex-linked, we write the genotypes for sex-linked traits using an X
with a letter representing the particular gene we are concerned about:
Example: XAXa or XAXA or XaXa or XAY or XaY
Steps to Solving Genetics Problems:
1. What genetic relationship is shown? (i.e. complete dominance, incomplete dominance, codominance,
multiple alleles, sex-linked, etc.)
2. Write a key.
3. Write the cross.
4. Show the Punnett square/ FOIL method.
5. Answer the question and circle.
Practice Problems: Complete all steps for each problem.
1. What is the probability of children being color blind if a normal visioned man marries a woman who is
a carrier for color blindness? Show your work. Let’s start you off with a key. . .
Key: XN = normal vision gene
Xn = color blind gene
2. Hemophilia, or bleeder’s disease, is inherited as a sex-linked recessive trait. What is the probability that
the children will have hemophilia if the mother is a hemophilic, but the father is normal? Show your
work.
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Biology S137
Andrianopoulos/Friel/McCloud/McHugh/Shoub
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
3. A hemophilic man marries a normal non-carrier woman. What is the probability that they will have a
hemophilic son or daughter? Show your work.
4. In Drosophila (fruit flies) eye color is inherited as a sex-linked trait. White eyes are recessive to red
eyes. What would be the expected phenotypes and their probabilities in the offspring of a white-eyed
female mated to a red-eyed male?
5. In cats, the gene for fur color is sex-linked. The two alleles for color may be responsible for either black
or orange fur. Calico is a mixture of black and orange. What is the probability that a black female and
an orange male can produce male-calico kittens? What is the probability that they will have femalecalico kittens? Show your work.
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Biology S137
Andrianopoulos/Friel/McCloud/McHugh/Shoub
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Sex Linkage 2
To remind ourselves that certain traits are sex-linked, we write the genotypes for sex-linked traits using an X
with a letter representing the particular gene we are concerned about:
Example: Example: XAXa or XAXA or XaXa or XAY or XaY
Steps to Solving Genetics Problems:
1. What genetic relationship is shown? (i.e. complete dominance, incomplete dominance, codominance,
multiple alleles, sex-linked, etc.)
2. Write a key.
3. Write the cross.
4. Show the Punnett square/ FOIL method.
5. Answer the question and circle.
Practice Problems: Complete all steps for each problem.
1. Suppose a man having hemophilia survives to have children, and his wife is a carrier of the gene for the
disease. What are the probable phenotypes of their daughters? Any carriers? What are the probable
phenotypes of their sons?
2. A normal visioned man marries a woman who is a carrier of colorblindness. What are the probable
phenotypes of their sons? Of their daughters? Are any of the daughters carriers?
3. As long as dad is not a hemophiliac, what will the phenotype of all his daughters be?
4. As long as mom is neither colorblind nor a carrier, what will the phenotype of all her sons be?
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Biology S137
Andrianopoulos/Friel/McCloud/McHugh/Shoub
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
5. In the pedigree below, shaded figures indicate individuals having hemophilia. Identify (circle) those
women who must be carriers of the gene for hemophilia.
6. In fruit flies, red eyes are dominant to white eyes. The genes for red or white eyes are carried on the Xchromosomes. What would be the expected offspring for each of the following crosses:
a. red-eyed male X white-eyed female
b. white-eyed male X homozygous red-eyed female
c. white-eyed males X heterozygous female
7. A normal visioned man marries a normal visioned woman whose father was colorblind. They have two
daughters who grow up and marry. The first daughter has five sons, all normal visioned. The second
daughter has two normal visioned daughters and a colorblind son. Diagram the family history
(pedigree), including the genotypes of all the individuals mentioned.
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Biology S137
Andrianopoulos/Friel/McCloud/McHugh/Shoub
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
8. In the accompanying human pedigree a certain character is presented by the solid squares and circles.
Answer the following questions about this character (trait):
a. Could the character be due to a simple dominant gene?
b. Could the character be due to a simple recessive gene?
c. Could the character be due to a recessive sex-linked gene?
9. In the accompanying human pedigree a certain character is presented by the solid squares and circles.
Answer the following questions about this character (trait):
a. Could the character be due to a simple dominant gene?
b. Could the character be due to a simple recessive gene?
c. Could the character be due to a recessive sex-linked gene?
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Biology S137
Andrianopoulos/Friel/McCloud/McHugh/Shoub
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Introduction: Cystic Fibrosis (CF) is the most common lethal genetic disorder among the Caucasian population
in the United States. Found on chromosome #7, CF is a recessive condition that cases that mucus lining of the
lungs to get too thick. As a result, the gas exchange process is inhibited. To facilitate the breathing process,
excessive mucus can be loosened by clapping the back. Extensive research has been done to improve the
quality of life for CF patients. Many CF patients today are prescribed antibiotics to control persistent infections
of the lung lining as well as other drugs, which try to the mucus that accumulates.
According to your statistical reports, about 1 in 5 Caucasians is a carrier of CF and 1 in 2,500 births will
have CF. Individuals with CF are usually diagnosed by age 2. Most children with cystic fibrosis are fairly
healthy until they reach adolescence or adulthood. They are able to participate in most activities and should be
able to attend school. Many young adults with cystic fibrosis finish college or find employment. Lung disease
eventually worsens to the point where the person is disabled. Today, the average life span for people with CF
who live to adulthood is approximately 35 years, a dramatic increase over the last three decades. Death is
usually caused by lung complications.
Directions: The following is a description of a family tree for the Walters family of Waterloo, Washington.
Many members of the Walters family have CF. Your assignment is to construct a family tree using the
information below. Indicate whether the individuals are afflicted with CF, carriers, or “normal”.
Remember…CF is a recessive genetic disorder. Good luck!
Relationships:
1. Mark and Marge are married and have four children: Martha, Matthew, Dave, and Donald.
2. Martha is married to Paul.
3. Matthew is married to Mary.
4. Dave is married to Diane and they have two kids: Lynne and Luke
5. Donald is married to Denise and they also have two kids: Nathan and Natalie
6. Martha and Paul have three kids: Samuel, Samantha, and Seth.
7. Matthew and Mary have two kids: Johanna and John.
8. Samuel is married to Sheila and they have two boys.
9. Samantha is married to Doug.
10. Seth is not married.
11. Johanna, Seth’s cousin, is also single.
12. John is married to Jessica and they have four boys.
13. Lynne is not married.
14. Luke is married to Leslie and they have a boy and a girl.
15. Nathan is married to Valerie.
16. Natalie, Nathan’s sister, is married to Vincent.
17. Nathan and Valerie have three boys.
18. Mark and Marge are both carriers of CF.
19. Mark and Marge’s daughter, Martha is afflicted.
20. Mark and Marge’s son Dave is a carrier.
21. Donald’s wife has CF.
22. John is not afflicted and not a carrier, but his wife, Jessica, has CF.
23. Luke carries the CF gene.
24. Luke’s cousins, Nathan and Natalie, are also carriers of CF.
25. Nathan’s wife, Valeria, has CF.
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Biology S137
Andrianopoulos/Friel/McCloud/McHugh/Shoub
Name_______________________________________
Date _______________ Per. 1 2 3 4 5 6 7 8
Analysis Questions:
1. What is the chance that Samuel and Sheila’s girls are CF carriers?
2. What is the chance that John and Jessica’s boys have CF? Are normal? Are carriers?
3. Nathan and Valerie’s first boy has CF. What is the chance that he received two recessive alleles for CF?
4. Nathan and Valerie’s other boys are both carriers. What is the chance that each is a carrier?
5. Samantha and Doug are thinking about having children. So are Natalie and Vincent. All are concerned
about the frequency of CF in the family and don’t want their children to have CF. Will any of Samantha
and Doug’s children have CF? Why or why not? SHOW YOUR WORK!
6. Will any of Natalie and Vincent’s children have CF?
7. Seth, who is not married, is also worried about the frequency of CF in the family. Is there any way he
can be certain his kids won’t have CF?
59