Download 1 Chapter 8b : Complex Inheritance NOTES

Chapter 8b Packet
Name ________________________________
Strategies for Success/Schedule
 Ch. 8b Reading Guide using the text. (pg 1-2)
 Use the videos on my website, to listen to the explanation of the notes as well as the problems. Pause the videos as you work out
the problems yourself and CHECK your answers after you have attempted yourself. (p. 3-8, 11)
 You can also use the ppt from my website to fill in the Chapter 8b notes. (p. 3-6)
 Fill in the answers on your own as you get to the problems for each section. (p. 3-8,11)
 Do the Gene Screen app (show me for a quiz grade). (p. 12)
 Complete the Blood- Typing Web Activity and turn in for a grade. (p.12)
 Use the study guides below and the problems from the extra practice (p. 9-10) to prepare for the Quiz
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Day 0- Reading Guide (all)
Day 1- Extra Practice-1-16, 21, 22
Day 2- Extra Practice-18-20, 24, 25
Day 3- Entire Test SG
Day 4- Study for quiz
 Using the videos/text/packet, do the Chapter 8b Extra Practice (p. 9-10) and study this for the Test
Complex genetics problems Quiz study guide (___________________)
Vocabulary
Genetic disorders
Be able to work one problem from
1. Test cross
9. Sickle cell anemia
each example
2. Probability
10. Cystic fibrosis
Test cross
3. Pedigree
11. Hemophilia
Pedigree
4. Sex-linked genes
12. Huntington’s disease
Incomplete dominance
5. Polygenic
13. Tay Sach’s Disease
Codominance (Blood-typing)
6. Incomplete dominance
14. Hypercholesteremia
Sex-linkage Cross
7. Multiple alleles
8. Codominance
Chapter 8b Test Study Guide (_______________)
1. Give the definition to the above vocabulary and diseases.
2. Understand the difference in the various types of inheritance: incomplete dominance, codominance, sex-linkage.
3. Explain what a test cross is and how it can be used to determine if an organism is true-breading.
5. Work out problems accurately that involve incomplete dominance, codominance and sex-linked traits.
6. Understand the difference between autosomal dominant, autosomal recessive and sex-linked traits on a pedigree.
7. Complete a monohybrid cross that goes through two generations.
8. Identify the pattern of inheritance, sex, and genotypes in a pedigree.
9. Complete a dihybrid cross accurately and give the genotypic and phenotypic ratio.
Chapter 8b Reading guide (Sections 3 and 4)
Determining Unknown Genotypes: Page 172-176
1. To determine an unknown genotype, individuals can perform a ________ __________.
2. A test cross, an organism with unknown genotype is crossed with a ____________ recessive individual.
3. The likelihood that a specific event will occur is called ___________________.
4. A family history that shows how a trait is inherited over several generations is called a _________.
5. _____________ are individuals who are heterozygous for an inherited disorder, but do not show symptoms. (They can
pass the allele for the disorder even though they don’t have the disorder.)
6. In a pedigree, a ___________ stands for a male; a _______________ stands for a female.
7. A shaded in shape means that an individual is ____________. A blank one means they are not.
8. Label the following letters on the picture to the right.
__√_a. male who has it
____b. male who doesn’t have it
____c. female who has it
____d. female who doesn’t have it
____e. husband and wife
____f. brother and sister
____g. generation 1
____h. generation 2
a
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9. If a gene is __________________ it will appear in both sexes equally.
10. A _____________________ is a chromosome other than an X or Y chromosome.
11. ______________________ traits are seen more common in males.
12. A ______________________ is located on the X or Y chromosome.
13. Most sex-linked genes are _________________; so males have only ___ copy and females have ____.
14. This means that males only need ___ copy of the recessive gene to have the condition or trait. Females are called
__________ if they have only one copy and can only have the condition or trait if they inherit ___ alleles.
15. Label the following exaples as males or females and if they have the trait, don’t have the trait or are carriers.
R- normal
r- colorblindness
X R X r _________________
X R Y _________________
X R X R _________________
X r Y _________________
r
r
X X _________________
16. If the gene is ___________________ __________________, every individual with the condition will have a
_________ with the condition. If it is ____________________ ___________________ it is not necessary for
someone with the condition to have any parent with the condition.
Complex Patterns of Heredity: Page 177-182
17. When several genes influence a character it is called ___________________ ____________________.
18. These genes may be on the same chromosome or scattered on different _________________________.
19. List 5 examples of polygenic traits in humans. _____________________________________________
_______________________________________________________________________________________
20. In some organisms, an individual shows a ________________ that is in between (intermediate) the two parents. This
is called _____________________ _________________. An example of this is the flower the __________________.
FR FR red flowers
Fw Fw white flowers
FRFw pink red flowers flowers
21. Genes with ______ or more alleles are said to have ________________ alleles. _________ types are determined in
this way. The three alleles are I A,I B , and i. Which two are dominant? ________ _________. Since neither are
dominant over each other A and B are said to be ___________________. Even though there are 3 alleles possible,
each individual can only have _____ of these alleles. How many different blood types are there? _____ What is the
genotype of an individual with type O? ____
22. If two dominant alleles are exprexssed at the same time, both characteristics are displayed and this is called ______.
This is different from incomplete dominance because ________ traits are displayed. What is the genotype of an
individual with type AB blood? ________________________
23. Sometimes an organisms ____________ (the way it looks) depends on the environmental conditions. ____________
flowers can vary depending on the pH of the soil. If the soil is acidic it will bloom _______; neutral to basic  _____.
24. The artic fox produces enzymes that control the pigment depending on the ___________. If it is warmer its coat is
____________; if it is colder it does not produce any pigments and its coat is ______________.
25. Changes in genetic material are called ___________. Harmful effects produced by thes are called _____________.
26. Some mutations are carried by ___________________ alleles (This means you have to have 2 of them; if you have
one you are a ________________). That means two normal people can produce a can have a child with the_______.
27. Write the correct genetic disorders from pages 180-181 in the blanks below.
_______________________a. A sex-linked recessive genetic disorder that impairs the bloods ability to clot.
_______________________b. Fatal, recessive disorder that causes the airways of the lungs to be clogged
with thick mucus, as well as liver ducts and the pancreas.
_______________________c. A recessive genetic disorder that produces a defective hemoglobin protein in
the red blood cells.
_______________________d. A recessive disorder that is a defective form of brain enzyme and causes
death in young children.
_______________________e. An autosomal dominant disorder that causes deterioration of the brain tissue,
but doesn’t hit until the 30’s or 40’s.
_______________________f. A dominant disorder that causes excessive cholesterol in the blood leading to
heart disease.
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Chapter 8b : Complex Inheritance NOTES
Types:
1. _______________________
2. _______________________ 3. _______________________
4. _______________________
Incomplete Dominance
Definition: ________________________________________________________________________
Analogy: Mixing together paint
Codominance
Definition: __________________________________________________________
Analogy: Mixing together pebbles
Multiple Alleles
Definition: ____________________________________________________
An example is ____________________ groups in humans.
Blood type, for example is determined by _____ alleles
A is ________________
B is ________________
O is ________________
Alleles
(Genotype)
Blood Type
(Phenotype)
Polygenic Traits
Definition:
_______________________________________________________
Ex: _____________________________
Practice: Codominance and Incomplete Dominance
1. Practice setting up keys for the phenotypes listed in each set. Remember that the "medium" trait must always be heterozygous.
a) Birds can be blue, white, or white with blue-tipped feathers. ______________________________________
b) Flowers can be white, pink, or red. ___________________________________________________________
c) A Hoo can have curly hair, spiked hair, or a mix of both curly and spiked._____________________________
d) A Sneech can be tall, medium, or short.________________________________________________________
e) A Bleexo can be spotted, black, or white._______________________________________________________
2. Now, can you figure out in the above list, which of the letters represent codominant traits and which are incomplete.
Codominant _____________ Incompletely Dominant _______________
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3. In some chickens, the gene for feather color is controlled by codominance. The allele for black is B and the allele for white is W.
The heterozygous phenotype is known as erminette.
a. What is the genotype for black chickens? ____
b. What is the genotype for white chickens? ____
c. What is the genotype for erminette chickens? ____
d. If two erminette chickens were crossed, what is the probability that:
They would have a black chick? ____%
They would have a white chick? ____%
e. A black chicken and a white chicken are crossed. What is the probability that they will have erminette chicks? ____%
4. In snapdragons, flower color is controlled by incomplete dominance. The two alleles are red (r) and white (w).
The heterozygous genotype is expressed as pink.
a. What is the phenotype of a plant with the genotype rr? ___________
b. What is the phenotype of a plant with the genotype ww? ___________
c. What is the phenotype of a plant with the genotype rw? ___________
d. A pink-flowered plant is crossed with a white-flowered plant.
What is the probability of producing a pink-flowered plant? ____%
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Multiple Allele Traits: Blood Type
Blood type exhibits codominance and multiple alleles. The chart below shows the phenotype and genotype of blood types.
Phenotype
Type A
Type B
Type AB
Type O
Genotype
IAIA or IAi
IBIB or IBi
IAIB
ii
AA or Ao
BB or Bo
AB
oo
Blood Type is controlled by 3 alleles: A, B, O. A & B are codominant, O is recessive.
1. a)
b)
c)
d)
What are the two genotypes possible for a person who has A blood? ___________
What genotype does a person with AB blood have? _______________
What genotype does a person with O blood have? _____________
What are the two genotypes possible for a person who has B blood? ___________
2. A man with type AB blood is married to a woman also with type AB blood.
What blood types will their children have and in what proportion? ____________________
3. A man has type B blood (homozygous) is married to a woman with type O blood.
What blood type will all of their children have? _______________
What is the genotype of the children? _____________
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4. A woman with type A blood (heterozygous) is married to a type B person (heterozygous). What
proportion of their children with have: A blood? ____ B blood? ____ O blood? _____
5. A woman with type A blood is claiming that a man with type AB blood is the father of her child who is also
type AB. Could this man be the father of the child? __________
Show the possible crosses; remember that the woman can have
homozygous or heterozygous genotypes.
6. A man with type AB blood is married to a woman with type O blood. They have two natural children
and one adopted child. Jane has type A blood, Bobby has type B blood, and Grace has type O blood.
Which child was adopted? _________________
7. A heterozygous type B man and a type AB woman want to have a child.
a. What are the chances that they will have a type B child?
_______
b. What are the chances that their child will be a type O? ________
c. Other than a blood type B, what other blood types could their child have? ____
d. The child is type AB. Could this child be from the man and woman? __________
8. A type AB man and type O woman decide to have a child.
What are the chances that they will have a type O baby? ________
What are the chances that their second child will have type B blood? __________
9. A type A woman and a type B man have a type O child.
a. What was the genotype of the man? _______
b. What was the genotype of the woman? ________
c. What are the chances that this couple will have a type AB child? ________
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Chapter 8: Notes- Sex-Linked Inheritance
Which Chromosome Determines our Sex?
–
Introduction: A human has _______ pairs of homologous chromosomes
 Pairs 1-22 are called __________________ – chromosomes not involved in determining sex
 Pair 23 – _______________________
How is Sex Determined?
–
–
•
•
Sex chromosomes are ____ and _____
Females are _______, Males are _______
Females can only make eggs with the X chromosome
Males make sperm with the X or Y chromosome,
so it is the ________ that determines the sex of a baby
Discovery of Sex-Linked Genes
– Discovered in fruit flies (drosophila melanogaster) by ________________________________
– Eye color is sex-linked in fruit flies. He discovered that alleles for eye color is carried on the __ chromosome
ONLY!
– NO ALLELES ON THE _______ CHROMOSOME
Why Fruit Flies?
•
Fruit Flies are ________________________________________________________________________
Sex-Linked Traits
–
Traits that are controlled by the sex chromosomes
 Colorblindness – ________________________________________________________
 Hemophilia – ___________________________________________________________
Example: H = Normal
h = hemophilia
– Important Rule: _____________________________________________________________
Female Genotypes
–
–
________________ : Normal Female (Homozygous Dominant))
________________ : Normal Female Carrier (Heterozygous)
________________ : Female with hemophilia (Homozygous Recessive
–
Male Genotypes
–
________________ : normal male without hemophilia
_________________: male with hemophilia
Sex-linked traits occur more in males than females because
– Males only need _________ “bad” gene on the X chromosome
–
But females need _________ “bad” genes on ________ X chromosomes
–
Sex-linked Practice Problems
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Tips: Sex linked traits are carried only on the X chromosome. Females are XX, Males are XY.
females can be homozygous dominant, recessive, or carriers XDXD or XdXd or XDXd
males only have one allele for the trait so they may only be XDY or XdY
1.
In the canary bird, green feathers are the result of the dominant gene “G” and the cinnamon color is the result of the recessive gene.
This is an example of sex-linked inheritance.
WRITE THE GENOTYPE FOR THE FOLLOWING:
a. A pure green female __________________
b. A cinnamon female ___________________
d. A green male _________________
c. A cinnamon male ____________________
e. A hybrid green female ________________
2.
If a pure dominant female was crossed with a cinnamon male, could any of the male offspring be cinnamon?
Make sure you work a punnett square to show your answers.
3.
Cross a cinnamon female with a green male.
Would any of the offspring be green?
Would any of the females be pure dominant? _________, What would be the phenotypic ratio? ___________
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Genetics: X Linked Genes
In fruit flies, eye color is a sex linked trait. Red is dominant to white.
1. What are the sexes and eye colors of flies with the following genotypes:
XRXr
_________________
X R Y _________________
R
R
X X
_________________
X r Y _________________
2. What are the genotypes of these flies:
white eyed, male ____________
white eyed, female ___________
red eyed female (heterozygous) ________
red eyed, male ___________
3. Show the cross of a white eyed female X r X r with a red-eyed male X R Y .
4. Show a cross between a pure red eyed female and a white eyed male.
What are the genotypes of the parents:
___________& _______________
How many are:
white eyed, male___
white eyed, female ___
red eyed, male ____
red eyed, female ____
5. Show the cross of a red eyed female (heterozygous) and a red eyed male. What are the genotypes of the parents?
___________ & ________________
How many are:
white eyed, male___
white eyed, female ___
red eyed, male ____
red eyed, female ____
Math: What if in the above cross, 100 males were produced and
200 females.
How many total red-eyed flies would there be?____
In humans, hemophilia is a sex linked trait.
Females can be normal, carriers, or have the disease.
Males will either have the disease or not (but they won’t ever be carriers)
6. Show the cross of a man who has hemophilia with a woman who is a
carrier.
What is the probability that their children will have the disease?
__________
= female, normal
= male, normal
= female, carrier
= male, hemophiliac
= female, hemophiliac
7. A woman who is a carrier marries a normal man. Show the cross. What is the probability that their children will
have hemophilia? _______________ What sex will a child in the family with hemophilia be? _________________
8. A woman who has hemophilia marries a normal man. How many of their children will have hemophilia, and
what is their sex?________________________
9. In cats, the gene for calico (multicolored) cats is codominant. Females that receive a B and an O gene
have black and orange splotches on white coats. Males can only be black or orange, but never calico.
Here’s what a calico female’s genotype would look like. X B X O
Show the cross of a female calico cat with a black male
What percentage of the kittens will be black and male? _________
What percentage of the kittens will be calico and male? _________
What percentage of the kittens will be calico and female? _________
10. Show the cross of a female black cat, with a male orange cat.
What percentage of the kittens will be calico and female? _____
What color will all the male cats be? _________________
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14. Individuals who lack an enzyme needed to form the skin pigment melanin are called albinos.
Normal skin pigmentation is dominant.
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Use D to represent the gene for normal skin and dd to represent the genotype for albinism. Where you cannot be sure
whether an individual with the dominant trait is heterozygous or homozygous, show the genotype as D-
1. In the pedigree above, if individuals 6 and 7 have another child, what is the chance that it will be an albino?
____________________________________________________________
2. What gender is individual 3 of generation II? ____________________
3. What relationship do individuals 6 & 7 of generation II share? _____________________________
4. If Individual 2 of generation III married a man who was homozygous for normal skin, what would be the probability of
them having an albino child? _________________
15. Individuals who can taste the chemical phenylthiocarbamide, PTC, have the dominant gene, A. Those with the
recessive genes, aa, cannot taste it. Remember: People with the trait are shaded.
Use “A” to represent the gene for a PTC taster, a dominant trait. Use “aa” for the PTC nontaster, the recessive trait
1. In the pedigree above, if individuals 4 and 5 in generation II have another child, what is the probability that it will be a
taster? _______________________________________
2. If individual 8 in generation II married a man with genotype AA, what is the probability that she will have a non-taster
child? _____________________________________
3. What relationship do individuals 3 & 4 of generation 2 from Figure 3 have? ________________
Chapter 8 Complex Genetics Extra Practice
Match the following vocabulary with the correct definition.
Name_______________
Date________ Period __
a. when an individual displays a phenotype that is intermediate (in between) the 2 parents
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b. genes with 3 or more alleles
c. family history that shows how a trait is inherited over several generations
d. when several genes influence a character
e. when an individual has the dominant phenotype, but their genotype is unknown
____1. Barr Bodies
____2. Codominance
____3. Incomplete dom
____4. Multiple alleles
____5. Pedigree
____6. Polygenic
____7. Probability
____8. Sex-linked genes
____9. Test cross
Match the following genetic disorders with its correct definition.
a. autosomal dominant disorder that causes brain, muscle deterioration in adults
____10. Cystic fibrosis
____11. Duchene’s Musc Dystrophy b. sex-linked, recessive genetic disorder that impairs blood clotting
c. sex-linked, recessive genetic disorder causes muscle weakness in children
____12. Hemophilia
d. recessive genetic disorder that causes defective hemoglobin molecules,
____13. Huntington’s disease
heterozygous individuals do not get malaria
____14. Hypercholesteremia
____15. Sickle cell anemia
e. recessive genetic disorder that causes deterioration of nervous system; death
____16. Tay Sach’s Disease
f. recessive genetic disorder that clogs the organs with mucus, no cure
g. autosomal dominant disorder that causes excessive cholesterol in blood
17.In a dihybrid cross of panthers, black fur (B) is dominant to
blue fur and big feet (F) are dominant to little feet. How many
offspring have blue fur with big feet? ____________
BBFF
BBFf
BbFF
BbFf
BBFf
BBff
BbFf
Bbff
BbFF
BbFf
bbFF
bbFf
18. A man with blood type A and a woman with blood type B
have a child with blood type O. The genotypes of the man, woman, and child respectively must be
_________
________
BbFf
Bbff
bbFf
bbff
__________
19.
In 1910, Thomas Morgan discovered traits linked to sex chromosomes in the
fruit fly. The Punnett square shown to the right shows the cross between
red-eyed females and white-eyed males. Fruit flies usually have red eyes.
If a female and male offspring from the cross shown to the right are allowed
to mate, what would the offspring probably look like? ____________________________
20. A woman carrying the gene for hemophilia marries a man who is a hemophiliac.
What percentage of their children can be expected to have hemophilia? ___________
21. Test Cross
What is a test crossed used for? Explain the procedure with the following example. A breeder has purchased a
“supposedly” purebred black coated dog. The gene for black coat is B, and the gene for white is b. When the owner’s
dog is crossed with a homozygous recessive dog, half of the offspring are black and the other are white. Explain why the
owner is upset at his purchase in biological terms, using a Punnett
square to support your answer.
22. Four o’clock plants
Red flowers- FR FR
Cross Parents: white flowers x pink flower
P genotypes ___ FW FW ________ X __ FRFW _______
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White Flowers- FW FW
Incomplete Dominance: Pink flowers (FRFW)
F1 genotype & ratio:________________________
F1 phenotype & ratio:_______________________
23. Blood Types (Codominance)
Given the following blood types of the parents complete the table.
(you will need to do work on a separate piece of paper)
All possible
Blood Type of
All possible
genotypes of children
parents
genotypes of parents
A
and
B
AB
and
O
All possible blood
types of children
Blood types not
possible for children
24. Next to each pedigree, tell if it autosomal dominant, autosomal recessive or sex-linked.
Also write the genotypes under each shaded individual.
25. Sex-linked traits:
A. In humans, normal color vision (N) is dominant over color blindness (n). A man and a woman
produced two colorblind sons and two daughters with normal color vision. The parental
genotypes must be _______________________
B. If a colorblind man marries a normal (homozygous) woman what are the probability for the children? ___________
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Genetic Crosses that Involve 2 Traits
In rabbits, grey hair is dominant to white hair.Also in rabbits, black eyes are dominant to red eyes.
These letters represent the genotypes of the rabbits:
GG = gray hair
Gg = gray hair
gg = white hair
BB = black eyes
Bb = black eyes
bb = red eyes
1. What are the phenotypes (descriptions) of rabbits that have the following genotypes:
Ggbb ____________________ ggBB ________________________
ggbb ____________________ GgBb _________________________
2. A male rabbit with the genotype GGbb is crossed with a female rabbit with the genotype ggBb The square is set up
below. Fill it out and determine the phenotypes and proportions in the offspring.
How many out of 16 have grey fur
and black eyes? ________
How many out of 16 have grey fur
and red eyes? ________
How many out of 16 have white fur
and black eyes? ________
How many out of 16 have white fur
and red eyes? ________
3. A male rabbit with the genotype GgBb is crossed with a female rabbit with the genotype GgBb The square is set up
below. Fill it out and determine the phenotypes and proportions in the offspring.
How many out of 16 have grey fur
and black eyes? ________
How many out of 16 have grey fur
and red eyes? ________
How many out of 16 have white fur
and black eyes? ________
How many out of 16 have white fur
and red eyes? ________
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4. Show the cross between a ggBb and a GGBb. You'll have to set the square up yourself!
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