Pick up your sheet from countertop

Read the FRONT Complete the BACK

side by creating your own pea plant crosses for each generation.

Genetics – The Study of Genetics – The Study of HeredityHeredityTEKS 6FPredict possible outcomes of various genetic combinations such as monohybrid crosses, dihybrid crosses, and non-Mendalian inheritance

Mendel cross-Mendel cross-pollinated pea pollinated pea plantsplants

He cut away the male parts of one flower, then dusted it with pollen from another

Mendel’s ConclusionsMendel’s ConclusionsHe concluded that factors (traits) are passed from one generation to the next.

Types of Types of AlleleAllele pairingpairing

HomoHomozygous zygous (purebred)(purebred) both alleles are the same

(BB – Brown eyes)

(bb – blue eyes)

HeteroHeterozygous zygous (hybrid)(hybrid) two different alleles

(Bb – Brown eyes)

GenotypeGenotypeOutward

appearancePhysical

characteristics

Examples:1.Brown eyes2.blue eyes

Arrangement of genes that produces the phenotype

Example:1. BB, Bb2. bb

PhenotypPhenotypee

Monohybrid CrossMonohybrid Cross

BB

Bb

Bb

bb

B

b

B b

Bb x Bb

BB= homozygous dominant; 1 of 4 = 25%

Bb= heterozygous dominant; 2 of 4 = 50%

bb= homozygous recessive; 1 of 4 = 25%

Chances of Brown Eyes: 3 of 4 = 75%

Chances of Blue Eyes: 1 of 4 = 25%

Dihybrid Cross: Dihybrid Cross: RrYy RrYy xx RrYyRrYy

Here’s your game plan:FIRST: FOIL the parent alleles just like you do for polynomials in math class

(Rr) (Yy) x (Rr) (Yy)(Rr) (Yy)First: RY RYRYOuter: Ry RyRyInner: rY rYrYLast: ry ryry

CROSSES WITH TWO DIFFERENT TRAITS

Dihybrid Cross: Dihybrid Cross: RrYy x RrYy x RrYyRrYy

RYRY RyRy rYrY ryry

RYRY

RyRy

rYrY

ryry

SECOND: take your results from your FOILing and place them on the sides of your Punnett square! Add like letters to like letters in the boxes.

RRYY

Dihybrid CrossDihybrid Cross

RRYY

RRYy

RrYY

RrYy

RRYy

RRyy

RrYy

Rryy

RrYY

RrYy

rrYY

rrYy

RrYy

Rryy

rrYy

rryy

Smooth/Yellow: 9 of 16

Smooth/green: 3 of 16

wrinkled/Yellow: 3 of 16

wrinkled/green: 1 of 16

9:3:3:1 phenotypic ratio

RYRY RyRy rYrY ryry

RYRY

RyRy

rYrY

ryry

THIRD: Complete your Punnett square! Use the results to analyze phenotypicphenotypic & genotypic outcomes.

Dihybrid Cross: crosses with Dihybrid Cross: crosses with two different two different traitstraits

Genetics Unit Overview Video Genetics Unit Overview Video Clip:Clip:Dihybrid Cross Dihybrid Cross SHORT CUT…SHORT CUT…

Let’s Practice Predicting Let’s Practice Predicting Probability of Probability of DihybridDihybrid Crosses:Crosses:

ACTIVITIES: 1.Guinea Pig Dihybrid Cross Practice (Notes)2.Dihybrid Cross Worksheet Turn-in #2 ONLY above for a Grade

EXIT TICKET: EXIT TICKET: Punnett Square PracticePunnett Square Practice

Do BOTH sides by completing monohybrid/dihybrid genetic crosses.

What you don’t finish will be H.W. due 1/14/14

H.W. Due 1/14/14H.W. Due 1/14/14

Finish Punnett Square Practice Handout

Study Quizlett.com Vocabulary Words for Genetics◦Quiz #1: Meiosis & Quiz #1: Meiosis &

Genetics is 1/14/14Genetics is 1/14/14◦KIM Blocks will be

done next weeknext week

Study Quizlet.com◦Search “rrisd

biology”◦Select “Genetics”