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Name ___________________________________ Per. ________ Test Date ___________

Unit 9- Human Genetics

| | |Fri 2/9 |

| | |Test- Unit 8 |

| | |Pedigree POGIL- Due @ end|

| | |of class on 2/16 |

|Mon 2/12 |Wed. 2/14 |Fri 2/16 |

|Pg. 1-5 Karyotype notes |Karyotype Lab |Pg. 6-9 Pedigree |

| | |POGIL due @ end of class |

|Mon 2/19 |Wed 2/21 |Fri. 2/23 |

|Pg. 10-12 Sex-Linked |Quiz |Pg. 13-14 Blood type |

|Pedigree |Royal Gene Lab |notes |

|Mon 2/26 |Wed. 2/28 |Fri. March 2nd |

|Counselor pull outs |PSAT |TEST OVER UNIT 9- HUMAN |

|Test Review |Test Review/ Edpuzzle/ |GENETICS |

|Edpuzzle videos |Quizalize | |

| |Thurs. 2/8 |

| |Test Unit 8- Mendel & Genetics |

| |Pedigree POGIL- Due Thurs 2/15 |

|Tues 2/13 |Thurs. 2/15 |

|Pg. 1-5 notes & Karyotype Lab |Pg. 6-9 pedigree notes |

| |POGIL due @ end of class |

|Tues 2/20 |Thur. 2/22 |

|Pg. 10-12 Sex-linked notes |Quiz |

|Royal Gene Lab |Pg. 13-14 Blood Type notes |

|Tues 2/27 |Thurs. March 1st |

|Counselor pull outs |TEST OVER UNIT 9- HUMAN GENETICS |

|Test Review | |

|Edpuzzle videos | |

UNIT 9 – HUMAN GENETICS

I. HUMAN GENETICS (pp. 311-313)

A. Human Somatic Cells

• _body__ cells are _diploid___ or _2n___.

• Each cell contains _46___ chromosomes, or _23___ pairs of chromosomes.

o Of the 23 pairs 22 are homologous ,contain the same genes in the same order, and are called autosomes.

o The 23rd pair of chromosomes are the sex chromosomes.

▪ Female= XX

▪ Male = XY

Human Gametes

a. Gametes are _haploid_, or _n__, and contain _23___ chromosomes.

b. Female gametes are _egg__ cells made in the ovaries in the process of meiosis

c. Male gametes are _sperm___cells made in the testes in the process of meiosis

d. Egg cells can only contain an X chromosome

e. Sperm cell produced has a _50__% chance of containing a Y and a _50__% chance of containing a X.

o the _male___ determines the sex of the offspring.

C. Analyzing Human Chromosome Numbers

1. Nondisjunction - Abnormal numbers of chromosomes in gametes result in genetic disorders called number disorders.

• Nondisjunction, which means _”not coming apart”.

• A chromosome pair fails to separate correctly in _anaphase so the gametes produced have an abnormal _number of chromosomes.

• Number disorders are not inherited; therefore, they cannot be predicted with _Punnett squares.

2. Karyotypes

• A photograph of _chromosome pairs__.

• Cells are stopped during mitosis and are stained, photographed and the photograph is enlarged.

• The chromosomes are cut out and arranged in _homologous pairs in size order, with the sex chromosomes making up the 23rd pair.

• Used to detect number disorders and to determine the _gender__ of an unborn child.

• Do not detect abnormal genes; therefore, a normal karyotype does not guarantee a _normal child!

II. HUMAN GENETIC DISORDERS – NUMBER DISORDERS (pp. 313-314)

A. Autosomal Number Disorders

• Most are _lethal____.

• The only autosomal number disorder that allows survival into adulthood is _Down syndrome____.

[pic]

1. Down syndrome

• Known as _trisomy 21 because there are _3 chromosomes at the __21st_ position, instead of _2___.

• Individuals have characteristic facial features; growth, behavior, and mental development are all affected.

• There is also a higher risk of _congenital____ heart defects.

• The incidence of babies with Down syndrome is much higher in _older__ mothers.

B. Sex Chromosome Number Disorders

1. Turner Syndrome

• Called _45 X0

▪ Because individuals lack 2nd sex chromosome

• Female, typically _short____ in stature, underdeveloped sexually, _sterile, with a normal life expectancy.

2. Klinefelter Syndrome

• Called _47 XXY___.

• Symptoms do not appear until _puberty_ at which time affected _males show poor sexual development and infertility.

• Treated with _testosterone___. Normal life expectancy.

Homework Practice Problems

1. Is this child a Male or a Female? _________ Is this child a Male or a Female? _________

2. What is wrong with this child? ______________ What is wrong with this child? _____________________

3. Male or Female? ___________ Male or Female? ___________

4. What is wrong with this child? ______________ What is wrong with this child? ______________

5. Male or Female? ___________ Male or Female? ___________

6. What is wrong with this child? ______________ What is wrong with this child? _____________

7. Male or Female? ___________ Male or Female? ___________

8. What is wrong? _______________________ What is wrong? _________________

B. Pedigrees (pp. 299-301)

• A diagram that follows the inheritance of a single _trait___ through several _generations_ of a family.

▪ Males are represented by _squares____

▪ Females, by _circles____.

• Individuals with the trait are represented with _shaded____ figures.

• Individuals shown with unshaded figures _do not show the trait___.

• Vertical lines connect _parents____ and _children____.

• Horizontal lines connect _spouses___ or _siblings__.

• Children are placed in _birth order__, from _left___ to _right_____.

1. The following pedigree shows the inheritance of a recessive trait.

a. How many generations are shown in this pedigree? _______________

b. How many children did Parents I1 and I2 have? ________ How many boys? _______ Girls? ________

c. How many children did Parents II1 and II2 have? ________ How many boys? _______ Girls? ________

d. Key: _______________________________________________________________________

e. To solve a pedigree: Label all ________________________________________________ first!

2. Determine the genotype of all individuals in this pedigree showing the inheritance of red hair, a recessive

trait.

Key: _________________________________

3. Determine the genotype of all individuals in the following pedigree showing the inheritance of a dominant trait.

Key: __________________________

Homework Practice Problems:

1. The following pedigree illustrates the inheritance of a recessive trait.

Identify the genotypes of each individual shown in the pedigree.

Key: __________________________________

2. The following pedigree illustrates the inheritance of a dominant trait.

Identify the genotypes of each individual shown in the pedigree.

Key: ________________________________

3. Examine the pedigree below showing the inheritance of albinism, a recessive trait. Identify the genotypes of all individuals

a. Key: ________________________

b. If individual E marries a man with albinism, what is the probability they would have a child with the disorder? Cross: ___________________________

c. Probability: ______________________

d. If this same couple (E x albino male) has a child with normal pigmentation, what is the probability their child is a carrier for albinism? _________________________

4. The following pedigree if for neurofibromatosis, a dominant trait. Identify the genotypes of all individuals.

Key: ___________________________

IV. INHERITED HUMAN GENETIC DISORDERS

A. Gene Mutations

• a change in the DNA sequence of the gene_.

• Causes Inherited human genetic disorders

B. Types of Inherited Genetic Disorders

1. Autosomal Genetic Disorders – Gene mutation is on any chromosome other than _sex chromosomes____.

2. Sex-Linked Disorders – Mutated gene is on the _X__ chromosome

V. GENETIC DISORDERS - AUTOSOMAL DISORDERS (pp. 345-348)

• Most genes are carried on the _autosomes, _44___ chromosomes other than the sex chromosomes.

• Most genetic disorders are _autosomal___ disorders.

• These disorders affect males and females _equally_ and are due to _gene___ mutations.

• Autosomal disorders can be divided into three groups based on the pattern of inheritance.

A. Autosomal Recessive Disorders (pp. 297)

1. Albinism – Characterized by failure to produce pigment, _melanin___. Affected individuals lack coloration in _eyes, _skin, and _hair. Very susceptible to _UV light____. Symptoms appear _at birth; _Normal life expectancy.

2. Cystic Fibrosis – Characterized by excess _mucus production in _lungs_, digestive system. Symptoms appear just after birth and include frequent respiratory infections, poor nutrition. With treatment, patients can survive to young adulthood. Cystic fibrosis is the most common _fatal__ genetic disorder in the _United States___ among Caucasians.

B. Autosomal Co-Dominant Disorders (pp. 303)

1. Sickle cell anemia is an autosomal co-dominant disorder that affects _hemoglobin___ production. Hemoglobin is the protein that binds _oxygen____ to red blood cells.

a. Individuals with the normal genotype, AA, do not have the sickle cell allele and produce only normal Hemoglobin.

b. Individuals that are SS produce abnormal hemoglobin that causes the red blood cells to “sickle” when oxygen availability is decreased;

i. for example, in high altitudes or during periods of stress. Sickled RBCs are more fragile, easily destroyed – results in lack of _energy____ due to decreased _ATP production in cells, blockage of blood vessels, and severe pain. Shortened life expectancy. Most common inherited disease in individuals of _African_ ancestry.

c. Heterozygotes (AS) produce both normal and abnormal hemoglobin and are said to have _sickle cell trait___. They do not show symptoms of the disorder. In certain areas, individuals with sickle cell trait have a benefit over individuals that lack the sickle cell allele because they are resistant to _malaria____. Malaria is a serious, sometimes fatal disease spread by _mosquitoes___ that affects millions of people each year in _Africa__. This increased malarial resistance has resulted in a very high incidence of AS individuals. If two heterozygotes marry and have children, they have a _25__% chance of having a child with sickle cell anemia.

C. Autosomal Dominant Disorders (pp. 298)

1. Huntington’s Disease – Fatal genetic disorder in which symptoms do not show until _30s to 40s___.

Characterized by deterioration of _nervous system_____.

2. Achondroplasia - _Dwarfism___

Homework Practice Problems:

Complete the following autosomal crosses:

1. Is Huntington’s dominant, recessive, or co-dominant? ___________________

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2. If a male heterozygous for Huntington’s and a homozygous recessive female having a child with Huntington’s?

a. Phenotypic ratio: ______________________

b. Genotypic ratio: _______________________

3. The following pedigree illustrates the inheritance of a Huntington’s Identify the genotypes of each individual shown in the pedigree.

Key: ________________________________

4. Is Sickle Cell dominant, recessive, or co-dominant? ___________________

If you cross a man who is heterozygous (have both sickle cell and normal cell) with a woman who does not have sickle cell.

5. What percent of the offspring will have sickle cell? _______________

6. What fraction of the offspring will have both sickle cell and normal cells? __________________

7. Is Cystic Fibrosis dominant, recessive, or co-dominant? ___________________

8. If you cross two heterozygous parents for Cystic Fibrosis what is the chance of having a child with Cystic Fibrosis? ______

9. The following pedigree illustrates the inheritance of a Cystic Fibrosis. Identify the genotypes of each individual shown in the pedigree.

Key: ________________________________

VI. GENETIC DISORDERS - SEX-LINKED DISORDERS

A. Sex-Linked Inheritance (pp.305-308)

• “Sex-linked” if it is located on a sex chromosome (_X__ or _Y__).

• In humans, sex-linked genes are almost always located on the larger _X___ chromosome.

o The _Y chromosome is much smaller and carries only a few genes related to male _sexual development.

o Females have __2__ X chromosomes;

o Males have _one____.

• Females will only show recessive traits located on the X chromosome if they are _homozygous recessive.

• Males will always show a recessive trait located on the X chromosome because he only has one X.

This results in _males___ having a much higher incidence of sex-linked disorders.

1. Genotypes for sex-linked traits are written using the X and Y chromosomes to show path of inheritance.

• Example, male-pattern baldness is a sex-linked recessive trait. If H = normal head of hair and h = baldness, bald male = _Xh Y_____; bald female = _ Xh Xh ___.

o Females can be __carriers___ for sex-linked recessive disorders = XH Xh The defective allele does not show!

o Males _cannot_____ be carriers for sex-linked traits because their 2nd sex chromosome is the _naked Y_!

2. Sex-Linked Punnett Squares –

• In sex-linked traits, probabilities for male and female offspring must be calculated separately because traits are _inherited differently___.

If a man with a full head of hair marries a woman who is heterozygous, what is the probability they would have a son who would go bald? A daughter?

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Key: ______________________________________

Cross: _____________________________________

Probability of bald daughter = ___________ Probability of bald son = ____________________

B. Sex-Linked Disorders – All of these disorders are sex-linked _recessive_____.

1. Color Blindness – Inability to differentiate and distinguish _colors_____.

2. Hemophilia – Missing an enzyme required for normal _blood clotting_____ - results in _uncontrolled bleeding_. Treated with blood transfusions, injections of missing factor.

3. Duchenne’s Muscular Dystrophy – Symptoms develop at _3 – 6 years______. Muscles _weaken, break down, leading to eventual death. No available _treatment____ or _cure_. Death usually occurs before adulthood.

C. Examples

1. A colorblind female marries a man with normal vision. What is the probability of colorblind children?

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Key: ______________________________________

Cross: _____________________________________

Probability of colorblind daughter = _________ Probability of colorblind son = __________

2. A genetics counselor interviews a couple with a family history of hemophilia to evaluate the possibility

of offspring with the disorder. The woman does not have hemophilia, but states that her father had

the disorder. The man is normal.

Key: ___________________________________________

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Cross: ___________________________________

Probability of daughter with hemophilia = ___________ Probability of son with hemophilia = __________

3. The following pedigree shows the path of inheritance of hemophilia through several generations. Identify the

genotypes of each individual.

[pic]

Key: ________________________________________________________________

Homework Practice Problems:

1. A hemophiliac man marries a woman who is a carrier of the hemophiliac condition. Draw a Punnett square representing the offspring of this marriage.

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a. What percentage of the offspring will be a hemophiliac? ___________

b. Is it possible for these parents to produce an offspring that is neither a carrier nor a hemophiliac? ______________

c. If so, would this individual be male of female? ___________

d. What would be the genotype of this individual? __________

e. Is it possible to have a female hemophiliac? _____________

2. In the case of the sex-linked gene responsible for hemophilia, a hemophiliac father never transmits hemophilia to his son. Explain why: ______________________________________________________________________________________

3. Red-green color blindness is also a sex-linked recessive trait in humans. Using B as the superscript for normal vision and b for color blindness, give the genotypes for the following:

a. A normal female:____________________ d. A normal male: _____________________

b. A carrier female: ____________________ e. A color blind male: __________________

c. A color blind female: _________________

4. A color blind male x a female carrier

Percent of boys who will be color blind: ___________

Fraction of girls who will be color blind: _____________

5. Normal vision male x color blind female:

Percent of boys who will be color blind: ___________

Fraction of girls who will be carriers: _____________

6. The following pedigree shows the path of inheritance of hemophilia through several generations. Identify the genotypes of each individual.

a. Key: ________________________

7. If individual III-2 marries an unaffected woman whose dad had hemophilia, what is the probability that their son will be hemophilic? _______________ What about their daughter? _______________

8. If individual III-3 marries a non-hemophilic male, what is the probability that they will have hemophilic daughters? _____ sons? _____

ANALYSIS OF HUMAN INHERITANCE

A. Punnett Squares & Multiple Alleles (pp. 304)

1. multiple alleles; _more than 2____ alleles.

• An example of this is ABO blood groups. There are _3____ alleles for this gene. Two of the alleles, _A__ and B are co-dominant, meaning __they always show if present. The third allele, o, is recessive, meaning it will only show if the genotype is _ii_.

• Each individual inherits 2_alleles for this gene, one from __mom____ and one from __dad_____.

The possibilities for blood group genotypes and phenotypes are:

|Phenotype |Genotype |

|Type A blood |IA IA or IA i |

|Type B blood |IB IB or IB i |

|Type AB blood |IA IB |

|Type O blood |i i |

1. A couple preparing for marriage have their blood typed. Both are AB. They ask you what types of blood their children may have. What would you tell them?

Cross: __________________________________

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Phenotype Ratio: ________________________________________

2. An old, rich couple dies in an accident. Soon a man shows up to claim their fortune, saying he is the long-lost son who ran away with a circus as a boy. Other relatives say he is lying. Hospital records show the couple'’ blood types were AB and O. The claimant is O.

Cross: __________________________________

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Is he an imposter? _______________

2. 2 different couples gave birth at the same time. One baby has blood type O and the other baby has blood type A. The nurses can not remember which baby goes with which parents. The first set of parents, the Lam’s have blood type A & blood type B. The second set of parents, the Buck’s have blood type A and blood type AB. Which baby belongs to which parent?

Lam’s: baby with blood type __________ Buck’s: baby with blood type __________

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Homework Practice Problems:

1. A person with type A blood (unknown genotype) marries a person with type O blood. What blood types are possible among their children. (Show 2 crosses)

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_____________________________

2. Two people with type O blood have three children. How many of those three children also have type O blood? _____________________________

3. A woman with blood type B marries a man with blood type O. Is it possible to have a child with blood type A?

__________________

4. Mom has blood type AB and child has blood type A what could dad be? (list all that apply) _________________________

5. Ralph has type B blood and his wife Rachel has type A blood. They are very shocked to hear that their baby has type O blood, and think that a switch might have been made at the hospital. Can this baby be theirs? _____________

6. Explain why or why not (use a Punnett square to help).

_________________________________________________

_________________________________________________

7. Both mom and dad have blood type AB. What are the possible outcomes of the children? ___________________

Alice has type A blood and her husband Mark has type B blood.

Their first child, Amanda, has type O blood.

Their second child, Alex, has type AB blood.

8. What is Alice’s genotype? _____________

9. What is Mark’s genotype? _____________

10. Candace has type B blood. Her husband Dan has type AB blood. Is it possible for Candace and Dan to have a child that has O blood? ___________

11. Explain why or why not (use a Punnett square to help).

_________________________________________________

_________________________________________________

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Prior Knowledge Needed

• Review what somatic cells are and where you would find them.

• Review what gametes are and where you would find them, and where they are made.

• Basic Genetic Vocab

• Punnett Squares

Looking at Human Chromosomes & What can go wrong:

• Identify how karyotypes are used to study genetic disorders

• Analyze different karyotypes to identify if it is a normal vs disorder

• Understand how nondisjunction is related to Down Syndrome and other abnormal Chromosomal numbers disorders

•

Using Punnetts & Pedigrees for autosomal disorders:

• Understand and be able to predict “Non-Mendelian” genetics including incomplete dominance, codominance, multiple alleles and sex-linked. Using both Punnetts and Pedigrees.

• Analyze traits over several generations by using both dominant and recessive pedigrees

• Identify different human Autosomal genetic disorders including:

o Recessive: Cystic Fibrosis, Albinism

o Co-Dominant: Sickle Cell Anemia

o Dominant: Huntington’s & Achondroplasia

Using Punnetts and Pedigrees for Sex-Linked Disorders:

• Identify different human Sex-Linked disorders including:

o Color blindness, Hemophilia and Duchenne’s Muscular Dystrophy.

• Analyze how Sex-linked traits are passed on through several generations by using a pedigree

What are somatic cells?

Give an example:

What are autosomes?

How many autosomes do humans have?

How many sex chromosomes do we have?

What are girls’ sex chromosomes?

What are boys’ sex chromosomes?

What is Nondisjunction?

Where/When does nondisjunction occur?

What type of mutation results from nondisjunction?

Can these mutations be inherited?

What is a Karyotype?

What is a Karyotype used for?

What are autosomes?

What are sex chromosomes?

What autosomal number disorder can produce a living baby?

What does Trisomy 21 mean?

What would result if you got trisomy 19?

What does it mean when you have a sex chromosome number disorder?

What is the name of the Female sex chromosome number disorder?

What is the name of the male sex chromosome number disorder?

What is a Pedigree?

In a Recessive pedigree all the shaded individuals show what?

In a Dominant pedigree all the shaded individuals show what?

So, in a dominant pedigree do you want to fill out the shaded individuals or the non-shaded individuals first?

What are autosomes?

What are sex chromosomes?

Autosomal disorders occur where?

What does Co-dominant mean?

So if you are heterozygous for sickle cell what does that mean?

What does Autosomal Dominant mean?

Where are Sex-linked disorders found?

So, if you are working with sex-linked disorders you must use ________ for girls and ________ for boys.

What is the only way for girls to show the sex-linked disorder?

Why?

Why can girls be carriers for sex-linked disorders?

Can boys be carriers?

Why?

If a boy has the disorder, which parent did he get it from?

This is a Sex-linked Recessive disorder, so what needs to be used to fill it out?

Boys= __________

Girls= __________

Are the shaded individuals normal or do they have hemophilia?

Who should you fill out first, the boys or the girls?

Why?

Blood type is both multiple allele and co-dominant. Which 2 letters are co-dominant?

What does co-dominant mean?

How many blood type letters are there?

What are they?

Can a mom with A blood & a dad with B blood produce a baby with O?

How?

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