Warm UpWarm UpTuesday, January 8, 2013

1. List the thing you enjoyed the most over your holiday break?

2. State one fact you know about genetics/DNA.

Genetics #1:Genetics #1:

Introduction to Genetics & Gregor Mendel

Reminder: Reminder: Cornell Notes Cornell Notes Divide your paper

◦Cues Section (1/3 page) ◦Notes Section (2/3 page)

At the END of today:◦Draw a horizontal line at end of notes◦3-5 complete sentence summary of that day’s

notes◦Must include SPECIFICS

ObjectivesObjectives1. Describe the importance of Gregor

Mendel.2. Define the term traits.

GeneticsGenetics= study of heredity

All living thing (plant, animal, or microbe) has a set of characteristics/traits

Inherit from parent(s)

Review: MeiosisReview: MeiosisFertilization

◦Sexual reproduction◦Male sperm & female egg join

Each haploid Latin Root: hapl = single

◦Produce new cell Diploid Latin Root: diplo = double

◦Develops into embryo (seeds in plants)

Gregor Mendel:Gregor Mendel: Austrian monk, teacher,

scientist, botanist Studied peas in 19th

century (1800’s) Made observations Designed experiments Mathematical analysis

Known as Father of Genetics

Gregor Mendel’s WorkGregor Mendel’s WorkBred peas in garden

1) Cross pollinated true breeding parent plants

2) Raised plants from seeds & made observations

3) Allowed offspring to self-bred & observed their offspring

True-breedingTrue-breeding AKA pure-bred SAME characteristics

seen in parent & offspring (IDENTICAL)

Do NOT see any other characteristics

The Original PlantsThe Original Plants Plants in 1 section had

different characteristics than plants in another section

Example: Seeds #1 Tall plants Seeds #2 Short plants Plants #1 greengreen seeds Plants #2 yellowyellow seeds

TraitsTraits= specific characteristics (examples: seed/flower

color, eye color, hair color)Mendel studied 7 different pea plant traits

Karyotype = picture of chromosomesUsed to detect chromosomal abnormalities

***Latin Root: karyo = nucleus***

Worksheet: Worksheet: KaryotypingKaryotyping

Warm UpWarm UpWednesday, January 9, 2013

Who is the Father of Genetics?

Genetics #2:Genetics #2:

Mendel’s Genetic Crosses, Dominance, Segregation

ObjectivesObjectives1. Contrast dominant and recessive alleles2. Define the term allele.

P generationP generationOriginal generation

of plantsParents called P or

“parental” generation◦Bridget & Brendan

are the parents therefore they are the P generation

P P

F1 generationF1 generationOffspring called F1

or “first filial” generation◦Filius and filia are the

Latin words for “son” and “daughter”

◦Kaya & Dorian are the children therefore they are the F1 generation

F1F1

HybridsHybrids= combination of 2 different things= offspring of crosses between parents w/ different traits Ex:

◦Zonkey(donkey & zebra)◦Liger(tiger & lion)◦Toyota Prius(electric & gas)

Mendel’s Cross Mendel’s Cross Pollination ExperimentsPollination ExperimentsCross Pollination = breeding 2 plants

that have different characteristicsWhat did he do?

◦Crossed parent plants w/ different characteristics (tall, short, green seeds, yellow seeds)

◦Studied the offspring

What were the results? What were the results? Mixture of all the traits?Mixture of all the traits?NO, all hybrids had characteristics of only

ONE parentsIn each cross, the character of the other

parent seemed to disappear!

DominanceDominance

= Have 2 different traits in parents, but only see 1 trait in offspring

Dominant Trait = Trait you seeRecessive Trait = Trait you do NOT see

Parent: Blue Eyes

Parent: Brown Eyes

Child: Brown Eyes

Phenotype vs GenotypePhenotype vs GenotypePhenotype = physical characteristics

◦Example: brown or blue eyesGenotype = genetic characteristics

◦Example: BB, Bb, or bb

1st Conclusion:1st Conclusion:

Genes = biological inheritance is determined by factors that are passed from one generation to the next (parent to offspring)

Alleles = different forms of a gene◦One on every chromosome

2nd conclusion: 2nd conclusion: Principle of DominancePrinciple of DominanceStates some alleles are dominant & others are

recessiveAn organism with a dominant allele will

ALWAYS show the dominant trait

Mendel’s FindingsMendel’s FindingsResult: All seeds yellow

◦Yellow seeds = Dominant ◦Green seeds = recessive

What happened to the What happened to the recessive traits?recessive traits?Did they disappear? Did they segregate?Experiment #2:

◦Crossed the different F1 generation ◦Made F2 generation

Mendel’s 2Mendel’s 2ndnd Experiment ExperimentResults:

◦Recessive traits reappeared

◦¼ or 25% of the plants had recessive traits in F2 generation

F1 plants produced gametes (sex cells) ◦2 alleles segregated from one another ◦each gamete carried a single copy of the gene

In the F1 generation, each gamete had 1 copy of the green gene or one copy of the yellow gene.

AKA Principle of Independent Assortment

Conclusion: Mendel’s Conclusion: Mendel’s Law of SegregationLaw of Segregation

Common Human Common Human Dominant TraitsDominant Traits

Thinking Strategy Thinking Strategy #19 T-Shirt Design#19 T-Shirt Design

• Directions: Design artwork for a t-shirt representing Mendel’s Genetics1) Front of shirt must have artwork showing the

concept using 3 colors2) Back of the shirt must have a 1-2 line cute or

clever (but clean) saying.3) A minimum of one paragraph (4-5 sentences)

must be written to describe how the artwork and saying explain Mendel’s Genetics.

Warm UpWarm UpThursday, January 10, 2013

What is the difference between a dominant trait and a recessive trait?

Genetics #3:Genetics #3:

Probability, Punnett Squares, Monohybrid Crosses

ObjectivesObjectives1. Define the term punnett square. 2. Predict the outcome of genetic crosses

using punnett squares.

Genetics & Probability:Genetics & Probability:Probability = likelihood that an event

will occur

Example: Coin toss◦ 2 possibilities: head or tails◦ probability of heads is 1 in 2 chance◦ i.e. ½ or 50% chance

Example Problem: If you flip a coin 3 times in a row what are the chances that you will get heads every time?

Answer: ◦Toss #1 have a 1 in 2 chance◦Same for Tosses #2 & #3◦ ½ x ½ x ½ = 1/8 ◦ 1 in 8 chance of flipping heads 3 times in a

row!

Genetics & Probability:Genetics & Probability:

Principles of probability are used to predict the outcomes of genetic crosses

Genetics & Probability:Genetics & Probability:

Punnett Squares Punnett Squares

= Diagram that shows the gene combinations that might result from a genetic cross

Homozygous vs Homozygous vs HeterozygousHeterozygousHomozygous = 2 identical alleles (TT or

tt) ◦Considered true-breeding◦Latin Roots: Hom = same

Heterozygous = 2 different alleles (Tt)◦Considered Hybrids◦Latin Roots: Hetero = other, different

Set up a Punnett Set up a Punnett squaresquare(Monohybrid Square) (Monohybrid Square)

1. Set up a 2 by 2 Punnett square (monohybrid cross)

2. Write the alleles for parent 1 on left side of Punnett squareEach gamete will have 1 of the 2 parental alleles1/2 of the gametes will have the dominant (T) allele 1/2 will have the recessive (t) allele

Set up a Punnett Set up a Punnett square square

3. Write the allele for parent 2 above the Punnett squareThis parent is heterozygous(Tt) ½ the gametes will have the dominant (T) allele1/2 will have the recessive (t) allele

Set up a Punnett Set up a Punnett square square

4. Fill in the squares for parent 1. Fill each square with the allele from Parent 1 that lines up with the row.

Fill in a Punnett square Fill in a Punnett square

T T

t t

5. Fill in the square for parent 2. Fill each square with the allele from Parent 2 that lines up with the column.

Fill in a Punnett square Fill in a Punnett square

T T T t

T t t t

Genotypes that resulted from Genotypes that resulted from monohybrid cross (Tt x Tt) monohybrid cross (Tt x Tt)

25% 50% 25% homozygous heterozygous homozygous

dominant dominant recessive

T T

t t

T t

T t

Phenotypes that resulted from Phenotypes that resulted from monohybrid cross (Tt x Tt) monohybrid cross (Tt x Tt)

75% Tall ◦TT = homozygous dominant◦Tt = heterozygous dominant

25% Short◦tt = homozygous recessive

Warm UpWarm UpFriday, January 11, 2013

1.What is the difference between genotype and phenotype?

2.Using the letter “A,” give an example of a genotype that is homozygous dominant?

Warm UpWarm UpMonday, January 14, 2013

1.List the genotypes and their percentages for the punnett square above.

Human Genome Video Human Genome Video

Warm UpWarm UpTuesday, January 15, 2013

Complete the following monohybrid punnett square:

Genetics #4:Genetics #4:

Punnett Squares & Dihybrid Crosses

ObjectivesObjectives1. Define the term dihybrid cross. 2. Predict the outcome of independent

assortment using a dihybrid cross.

Dihybrid Crosses

= 2 factor cross for 2 different traitsExample:

◦Bb B = Brown Eyes b = Blue Eyes

◦Ss S = Tall s = Short

Heterozygous Heterozygous Dihybrid CrossesDihybrid Crosses9:3:3:1 results anytime you have 2

heterozygous adultsExample

◦9 brown eye & tall ◦3 brown eye & short◦3 blue eye & Tall◦1 blue eye & short (recessive both traits)

Warm UpWarm UpWednesday, January 16, 2013

What is the ratio that results from crossing two heterozygous parents in a dihybrid cross?

Latin Roots Quiz Latin Roots Quiz Take everything off your desk

except something to write with.

Warm UpWarm UpThursday, January 17, 2013

1.Write out the gametes for a guinea pig with the genotype AaBb.

AaBb

Genetics #5:Genetics #5:

Co-Dominance & Incomplete Dominance

ObjectivesObjectives1. Define incomplete dominance. 2. Predict the outcomes of incomplete and

codominance.

Summary of Summary of Mendel’s Principles:Mendel’s Principles:

Inheritance of biological characteristics ◦ Determined by genes ◦ Passed from parents to offspring

Adults have 2 copies of each gene◦1 from each parent

Genes usually segregate independently

Beyond DominanceBeyond DominanceSome alleles are

neither dominant nor recessive.◦Example: height

Many traits controlled by multiple alleles or genes

Mendel did not understand this complex relationships

Incomplete DominanceIncomplete Dominance = blending of parental traitsExample:

◦F1: red flower (RR) and white flower (rr)◦F2: pink (Rr)

Codominance:Codominance:= see both alleles in phenotypeHeterozygousNeither dominant or recessive phenotypeHybrid traitExample: Roan Coat in Horses

◦Red + White = Red & White Coat

Codominance: Blood TypesCodominance: Blood TypesBlood Type A

◦Option 1: IAIA

◦Option 2: IAiBlood Type B

◦Option 1: IBIB

◦Option 2: IBiBlood Type AB

◦Only Option: IAIB

Blood Type O◦Only Option: ii

Which blood types are Co-Dominant?

◦Blood Types A & B (IAIB)

Which blood type is recessive?

◦Blood Type O (ii)

Codominance: Blood TypesCodominance: Blood Types

PedigreesPedigrees= diagram that shows occurrence of particular genes within a familyShows inherited traitsShapes:

◦Circle = Female◦Square = Male

Multiple AllelesMultiple Alleles

= 3 or more alleles code for a traitExample:

◦Blood Types: IA IB i

◦coat color of rabbits

Polygenic traitsPolygenic traits

= interactions of several genes at different lociEx: height, skin color, weight

Remember: Locus = location on chromosome

Warm UpWarm UpFriday, January 18, 2013

What are the four possible blood types for humans?

Genetics QuizGenetics QuizGet out something to write with and keep your genetics notes out on your desk.

Warm UpWarm Up

Tuesday, January 22, 2013

What would be the 4 female gametes from the following genotype: AaBb?

Blood Typing Blood Typing & Pedigrees& Pedigrees

Warm UpWarm UpWednesday, January 23, 2013

What is a pedigree? Define in words AND with a picture.

Genetics Stations Genetics Stations LabLab

Warm UpWarm UpThursday, January 24, 2013

What is the difference between incomplete dominance and codominance?

Gems of Wisdom: Gems of Wisdom: GeneticsGenetics

Warm UpWarm UpFriday, January 25, 2013

Using the letters “B” and “R” (dihybrid cross), write a homozygous dominant genotype.