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”