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Name: _________________________________ Date: _________________ Per:______ Genetic Notes Genetics

Genetics Vocab Identify the definitions and/or vocabulary words below. You will need to know these terms moving forward! 1. P Generation

2. Hybrid (F1) Generation

3. F2 Generation 4. Monohybrid Cross

5. Dihybrid Cross 6. Punnett Square

7. Dominant (allele)

8. Recessive (allele)

9. Genotype

10. Phenotype Gregor Mendel ° The scientific study of heredity is called __________________________________! ° Who was Gregor Mendel?

- Austrian Monk - Worked with _____________ ____________________ in his monastery

° Correctly believed that __________________ factors (__________________) retain their _____________________________ from generation to generation

- EXAMPLE – marbles in a bag Why Pea Plants? ° Mendel chose to study garden peas, because: 1. They reproduce ______________ & have a short life cycle

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2. They have seven distinct & _____________________ traits 3. They produce ___________ offspring in one cross 4. Ease in manipulating _________________________ (because they ________-fertilize AND cross pollinate) Mendel’s Experiments ° After studying __________ _______________, Mendel concluded that:

- Traits are passed from one generation to the next through _____________ - Each trait is controlled by a different form of a gene called an ____________________ - Some alleles are ________________ to others called recessive traits

Question: Have the recessive alleles disappeared or are they still present in the parents? What does “A” represent?

A. Sex Cell B. Allele C. Trait D. Both B and C Mendelian Inheritance o Three types of Mendelian Patterns of Inheritance

1. ______________________ Dominance 2. Law of __________________________________ 3. Law of _____________________________ Assortment

What is Complete Dominance? o Recessive alleles will always be _____________________________ by dominant alleles

- _______ will show a dominant trait - _______ will show a recessive trait

o _________________________________ – two identical alleles for a trait § AA – homozygous ________________________ § aa – homozygous ________________________

o _________________________________ – two different alleles for a trait - Aa – ___________________________________ one of each allele

Law of Independent Assortment

° Mendel used pea plants to see patterns in the way various traits were inherited Using his data, he saw that when two or more characteristics are inherited, individual factors assort independently during gamete production

- giving different traits an equal opportunity of occurring together - Example: Green pea color isn’t always inherited with wrinkled pea shape….green peas can be smooth

and round too! - Example #1 – blonde hair isn’t always with blue eyes - Example #2 – peas can be green and wrinkled OR green and round

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- This idea is called the Law of Independent Assortment! ° This explains genetic __________________ among organisms

Law of Segregation o Alleles _________________________________(separate) from each other during the formation of gametes.

o Occurs during ________________ in __________________ o ______________________________________ separate à ________________ the gametes

carry one allele and the other half carry the ___________ allele. o Ex: each offspring will acquire one allele from each parent.

o Evidence: Mendel crossed the first generation and saw that the recessive trait showed up in about _____ of ______ plants.

Practice Problem #1 – A) A purebred purple flower mates with a purebred white flower and they have all purple flower “babies.” If two of the purple flower babies cross and have a mixture of both purple and white flowers, what color/trait can we say is RECESSIVE? ___________________________ WHY? B) What would the GENOTYPE be for the recessive flower? ________________________________ C) What flower color is DOMINANT? _______________________________ D) What would the GENOTYPE be for the dominant flower color in the “P” generation? _________________ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Punnet Squares! What is a Punnett Square?

° Way to predict ALL ___________________ outcomes of a cross

How do you read a Punnett square? ° Axes represent possible gametes from each parent ° Boxes represent possible genotypes for offspring

What is a monohybrid cross? ° Crosses to show inheritance of only _____________ specific _____________ ° Example: Crossing a homozygous dominant TALL parent with a homozygous recessive SHORT parent.

° ONLY crossing for the “height” trait

Monohybrid Ratios ° Genotype Ratio – should be broken down by genotype(s) and number(s)

° # TT : # Tt : # tt ° 0 TT : 4 Tt: 0 tt à so, we say _____________ Tt

° Phenotype Ratio – should be broken down by physical description(s) and number(s) ° # Tall : # Short

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° 4 Tall: 0 Short à so we say 100% ______________________

Punnett Square Problems Practice #1 Step 1 -

° Define the _____________ ° After reading the problem, create a key, in which you will define the alleles ° For example for the problem “If a homozygous round pea plant is crossed with a heterozygous round

pea plant, what will their offspring look like?” on your paper, you should write: Key: R = round à _____ = ____________

Step 2 – ° Define the _______________ ° The parents will be ________ x ________

Step 3 –

° Draw the Punnett square with the parent genotypes on top (RR) and across (Rr) Step 4 –

° Cross the parents to find the probability of offspring by bringing the top letter down and the side letter over…

Step 5 – ° Find the genotype and the phenotype of the offspring. ° Genotype: _____________________________ (letters) ° Phenotype: physical ____________________________

Finished Product!

° Your finished punnett square should look like this…. Key: R = _______________ r = _______________ Genotype: 2 ______ : 2 ______ Phenotype: 100% ________________ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Practice #2

R r

R R

RR RR

Rr Rr

If a homozygous round pea plant is crossed with a heterozygous round pea

plant, what will their offspring look like?

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Yellow seeds are dominant to green seeds in peas. Show a cross between a homozygous yellow seed and homozygous green seed. Key: Y = _______________ y = _______________

Cross: Genotype: Phenotype: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Practice #3 In pea plants, round seeds are dominant over wrinkled. A plant that is heterozygous for round seeds is crossed with another heterozygous plant. Hint: Use the letter “R” for your key! Key: _____ = _______________

_____ = _______________

Cross:

Genotype:

Phenotype: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Dihybrid Punnett Squares! What is a Dihybrid Cross?

° A cross that shows inheritance of ___________ ___________________________ traits ° For example: homozygous round & yellow crossed with a heterozygous round & yellow seed

- Homozygous round and yellow - RRYY - Homozygous wrinkled and green - RrYy

Setting up a Dihybrid

° Step #1 – Read the problem & list all 4 _______________ ° For example:

- R = round - Y = yellow - r = wrinkled - y = green

° Step #2 – Create the parental genotypes (each will be 4 letters) ° Example: _______________ (Round, Yellow) x _______________ (wrinkled, green)

° Step #3 – Using the “foil” method, à First, Outer, Inner, Last à determine the sets of gametes (up to 4 possibilities)

° Example: 1. RRYY à ____________

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2. RrYy à ________, ________, ________, ________

° Step #4 – Fill in the tops and sides of punnett square with gamete combinations ° Example:

° Step #5 – Genotype and Phenotype as usual (remember the key!) ° Example:

- RRYY = ________________________

- RRYy = Round and yellow

- RrYY = _________________________

- RrYy = Round and yellow - So…we can say ALL the offspring (___________) will be _______________ and yellow!

Dihybrid Genotype Naming Practice

° In rabbits, grey hair (G) is dominant to white hair. Also, black eyes (B) are dominant to red eyes. What are the phenotypes of rabbits that have the following genotypes:

- Ggbb: ________________________________

- ggBB: ________________________________

- ggbb: ________________________________

- GgBb: ________________________________

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Dihybrid Example Problem #1

° Round is dominant over wrinkled ° Yellow is dominant over green

Two pea plants produce offspring. One is round and heterozygous for yellow seed color. The other is wrinkled and heterozygous for yellow seed color.

Step 1 – ° Determine the parental genotypes = _____________ X _____________ ° Determine the possible gametes!

1. 2. 3. 4.

Step 2 – ° Set up the dihybrid cross using the gametes from before…

RY

RY Ry rY ry

KEY:

R = round r = wrinkled Y = yellow y = green

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Step 3 –

° Determine the genotype and phenotype!

° Genotype: 1 ___________: 2 ___________:: 1 ___________

° Phenotype: _______________________________________

Dihybrid Example Problem #2 ° Black fur (B) is dominant to white fur ° Long hair (L) is dominant to short hair

Two guinea pigs mate. The dad is homozygous for black fur and long hair. The mom is also homozygous, but for white fur and short hair. 1) Determine the parental traits 2) Determine the possible gametes of each parent 3) What is the only genotype possibility for their offspring? Dihybrid Example Problem #2 –SOLUTION 1) DAD = _______________ MOM = _______________ 2) Determine the possible gametes of each: DAD à _________________________ MOM à _________________________

3) What is the only genotype possibility for their offspring? GENOTYPE: _____________________ PHENOTYPE: _____________________ Dihybrid Example Problem #3

o Find the possible gametes and offspring phenotype possibilities if a black lab (EEBB) mates with a chocolate lab (EEBb).

Phenotypes: ____________________________________ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Pedigrees

° A pedigree is a _____________________________ that traces specific ______________ across many _______________________________

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What would a dominant trait look like in a pedigree?

o It will show up in

_________________________ generation. o How do you know?

What would a recessive trait look like in a pedigree?

° It will ____________ be in ________________

generation. ° Why????

° Pedigrees help us determine whether alleles are ____________________ or ______________________. ° How do you create a pedigree?

- Collect information about a family’s history - Organize the information in a family tree - Apply Mendel’s concepts and principles

Pedigree Basics: ° Male = Square ° Female = Circle ° Horizontal Line = Marriage ° Dotted line = adoption ° By coloring in the shapes you are indicating an __________________ trait/phenotype ° Other pedigree symbols…

Identical Twins = Incest Marriage = Fraternal Twins = Death =

° Pedigrees can help us determine if a trait is: 1. Dominant or ______________________

2. ______________________ (passed on _______ or ______ chromosome) OR ___________________ passed on chromosomes _____________)

Offspring are drawn below the parents

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Let’s Practice! 1. Are freckles dominant or recessive? 2. What genotype MUST II-4 and II-5 have? 3. What about III-4? 4. What about III-10? Non-Mendelian Inheritance � Five types of non-Mendelian Patterns of Inheritance

o Sex-linked inheritance o Incomplete Dominance o Codominance o Multiple Alleles o Polygenic

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Sex Linked Heredity How is Gender Determined? � ________________________ ALWAYS give an X CHROMOSOME � Male can give either an _________ or a _________ � What is the probability of having a boy baby? ________________ � What is the probability of having a girl baby? ________________ What is a Sex-linked gene? � Any gene that resides on a sex chromosome � Y- linked:

¡ Only ___________________ will express the trait � X-linked:

¡ Females AND males will _______________________ the trait � Colorblindness (recessive) � Hemophilia (recessive)

� Is there a bias for one gender to be more affected by an X-linked gene than the other? WHICH & WHY?

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What is a Sex-Linked gene? o In an XaY the "a" recessive allele will ______ ____________________ in his phenotype o In an XaXA the "a" recessive allele will ________ be _______________ in her phenotype o Sex linked genes can be on either the X or Y chromosome

o Genes on the X chromosome can be passed to either sons or daughters. o **Genes on the Y chromosome can only be passed to sons! NOT to daughters**

o Females can be: - Homozygous affected à __________________________ - Homozygous unaffected à __________________________ - Heterozygous carriers à __________________________

o Males will be: - Affected à ________________ - Unaffected à ________________

Colorblindness o Red-green colorblindness is caused by _________________________ cells (cones) in the eyes that

aren’t working properly o Individuals who are affected can’t distinguish ______________ from ________________ o Usually inherited as _________________________ __________________ traits

- Males only need to inherit ____________ recessive allele to have disorder (XaY) - Females must inherit ____________ recessive alleles to have the disorder à 1 allele from

mother and 1 allele from father (XaXa) Sex-Linked Practice Problems #1 Hemophilia is a sex-linked gene carried on the X Chromosome. Let’s practice phenotypes possibilities for sex-linked individuals! List all possible outcomes for hemophilia: - XHXH à ___________________________ - XhXh à ___________________________ - XHXh à ___________________________

- XHY à ___________________________ - XhY à ___________________________

Sex-Linked Practice Problems #2 Cross a regular female and a hemophilic male. Identify the phenotypic values for each gender. Parent Cross: Genotypic Ratio: Phenotypic Ratio: __________ girls will be _______________ for hemophilia and __________ of boys will __________ hemophilia

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Sex-Linked Practice Problems #3 A woman who is a carrier for colorblindness (but has normal vision) mates with a man that is colorblind. Create a key to identify all possible genotypes. B = normal “color-seeing” allele b = colorblind allele

XBXB = normal female ___________ = carrier female ___________ = affected female ___________ = normal male ___________ = hemophiliac male Using your key, complete a punnett square to identify their possible offspring. Genotypic Ratio: Phenotypic Ratio BY GENDER: Sex-Linked Practice Problems #4 A carrier female marries a normal male. What are the chances that they will have a hemophiliac child? Key: H = normal “healthy” allele h = hemophilia allele

Phenotypic Ratio:

1 ____________ daughter 1 ____________ daughter

1 ____________ son 1 ____________ son

__________% they’ll have a child with hemophilia? Colorblindness through Pedigrees

o Colorblindness is passed along on the X Chromosome (just like hemophilia)

o Using the pedigree (right), what is the genotype of II-2?

XHXH = normal ______________________ XHY = normal _____________________

____________ = carrier female ____________ = hemophiliac male

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- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Incomplete Dominance & Codominance What is Complete Dominance?

� Organism only needs one dominant allele to obtain the dominant genotype ¡ Both in the homozygous (DD) or heterozygous (DD) state

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - What is Incomplete Dominance?

° Incomplete Dominance – type of ___________________ when the _____________________ phenotype is a mixture of the two _______________________ phenotypes

o Neither allele is completely dominant or recessive o NOT blending

Example: Green beta fish (CGCG) Blue beta fish (CBCB) Teal beta fish (CGCB)

CBCB x CGCG = teal beta fish

Incomplete Dominance Problem #1 If a red four o’clock flower is crossed with a pink four o’clock flower what will their offspring look like? CRCR = red CWCW = white

_______ = pink

Cross: Genotype Ratio: Phenotype Ratio: Incomplete Dominance Problem #2 In the four-o’clock plant, homozygous shows the red flower color and homozygous shows the white flower color. Cross a red plant with a white plant and list the genotypic and phenotypic ratios. Cross: Genotype Ratio: Phenotype Ratio:

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What is Codominance? ° When both the dominant and recessive trait is expressed _____________________ ° ______________________ allele is dominant or recessive ° Example: A flower that is homozygous for red flowers (RR) is crossed with a plant that is homozygous

for blue color (BB). The offspring (RB) will have spots of blue and spots of red but NO purple - __________ x __________ = blue and red spotted (RB) - ***NOTE: the letters are ALWAYS CAPITAL!***

Codominance Example

° In cattle, fur color can either be red (CRCR), white (CwCw) or roan (CRCw). ° Example: Roan fur is both red hairs and white hairs together

Codominance Example #1

° Black feathers and white feathers in chickens are codominant. In the heterozygous condition the feathers are called “erminette” and appear blue.

° CBCB = _______________________ ° CWCW = _______________________ ° CBCW = _______________________

Parents Cross: Genotype Ratio: Phenotype Ratio: Codominance Example #2 Roan is a coat color found in some cows

° __________ = red hair ° __________ = red and white hair (Roan) ° __________ = white hair

Parents Cross: Genotype Ratio: Phenotype Ratio: - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Multiple Alleles & Codominance

� Most genes can be found in more than 2 forms à _____________________________ ° Example à blood types

� There are 3 alleles (____, B and ____) � We write the alleles:

1. ____ = ____ 2. ____ = ____ 3. ____ = ____

� When combined, they create 4 blood phenotypes: ____, B, ____, and _____

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� Each parent gives us ________ allele � Because there are 3 alleles, there are _____________ total combination possibilities

- Fill in the following table as a helpful guide….! Phenotype Genotype Can Receive Blood From…

A

B

AB

O

Blood Type Key in Detail

� A Blood Type ¡ ________________________ Type A à IAIA ¡ Heterozygous Type A à IAi

� B Blood Type ¡ ________________________ Type B à IBIB ¡ ________________________ Type B à IBi

� AB Blood Type (________________________) IAIB ¡ AB is the universal receiver

� O Blood Type (________________________) ii ¡ O – is the universal donor

Rh and Antigens

� Antigens are protein markers on the surface of cells that help the immune system identify a foreign cell/virus

� “A” and “B” are antigens that are on the surface of red blood cells ° People have one, both, or none

• If you don't naturally produce the antigen, your body's white blood cells will attack and destroy red blood cells that carry them

Examples: ² A person with AB+ blood is a universal receiver, because they already produce all of the normal

antigens present on red blood cells ² A person with O- is a universal donor, because it lacks all antigens à no one's body will

recognize it as foreign Rh Factor

• Rh factor is another protein • People are either Rh+ (have protein) or Rh- (do not have protein) • If you are Rh- and receive Rh+ blood, immune system makes proteins that cause blood cells to SWELL

= BURST

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• Thus, when getting blood, both the blood type and Rh factor must be matched!!!

Practice Problem #1: #1) A type AB woman marries a type O man. What are the possible genotypes of their offspring?

Phenotype: Genotype: Phenotypic Ratio: Genotypic Ratio:

Practice Problem #2: Papa Whittaker is convinced his blood type is AB-. Mama Whittaker has given blood many, many times and knows that she is O+. Ms. Whittaker has also given blood and is A+. Emily Whittaker is O+, just like Mama Whittaker. A) What is the genotype of II-3? B) What are the possible genotypes and phenotypes for Shannon Whittaker? Explain! C) Is it possible for Papa Whittaker to be AB-? Explain. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Polygenic Traits � A trait is determined by ____________ genes � Results in a wide range of phenotypes � Example: Skin color, eye color, hair color…. Challenge Problem: Key:

� Capital M = Melanin, darker skin color � Capital N = No Melanin, lighter skin color

Imagine the following couple: NN NN NN (female) x NN MN NN (male)

1. Give the phenotypes for each parents. Female: ___________ Male: ___________

2. What is the genotype of the darkest child they could have? __________________________________ 3. What are the odds of producing such a child? __________

Show your math: 4. What is the genotype of the lightest child they could have? __________________________________ 5. What are the odds of producing such a child? __________ What are the odds of having a child that is

heterozygous for all three genes? _________