1. Start-up for12/11/13 1. Summarize Mendel’s Law of Segregation.
2. Complete the following single trait crosses and answer the questions:
Trait: Plant Height
T = Tall t = short
A. If you cross a heterozygous male (Tt) with a homozygous recessive female (tt), what percentage of the offspring do you expect will be short? (show your punnett square work)
B. If you cross a homozygous dominant male with a homozygous recessive female, how many of the offspring will be short?

2. Start-up for 12/11/13
2. Complete the following single trait crosses and answer the questions:
Trait: Plant Height
T = Tall t = short
A. If you cross a heterozygous male (Tt) with a homozygous recessive female (tt), what percentage of the offspring do you expect will be short? (show your punnett square work)

3. Start-up for 12/11/13
2. Complete the following single trait crosses and answer the questions:
Trait: Plant Height
T = Tall t = short
B. If you cross a homozygous dominant male with a homozygous recessive female, how many of the offspring will be short?

4. Chapter 11 Section 3, Pgs. 270-273 and Chapter 14, Pg. 344
Mendelian Genetics
Chapter 11 Section 3, Pgs and Chapter 14, Pg. 344
Objective: Students will
A) Summarize Mendel’s Law of Independent Assortment
B) Identify how dihybrid crosses support independent assortment
Complete punnett squares for two trait crosses
Summarize Mendel’s three laws

5. Mendel’s Laws 1. Law of Dominance 2. Law of Segregation 3
Mendel’s Laws 1. Law of Dominance 2. Law of Segregation 3. Law of Independent assortment

6. A) Summarize Mendel’s Law of Independent Assortment
Alleles for different traits are distributed to gametes (& offspring) independently of one another. Ex. Tall plants are not always found with yellow seeds
This law can be illustrated using dihybrid crosses – two trait crosses of hybrids (TtYy).

7. B) Identify how dihybrid crosses support independent assortment
TtRr X TtRr
Each parent can produce 4 types of gametes.
Use FOIL from math to ID gametes. First, Outer, Inner, Last
TR, Tr, tR, tr
Cross is a 4 X 4 with 16 possible offspring.

8. B) Identify how dihybrid crosses support independent assortment
Traits: Seed shape & Seed color
Alleles: R round r wrinkled Y yellow y green
Mendel’s Questions:
Does round always come with yellow and does wrinkled always come with green? Are traits connected?
RrYy x RrYy
RY Ry rY ry
RY Ry rY ry
All possible gamete combinations

9. B) Identify how dihybrid crosses support independent assortment
B) Identify how dihybrid crosses support independent assortment. Place gametes of parents from foil on the “Big Square”. Parent #1 gametes on the top. Parent #2 gametes on the left side.
RY Ry rY ry RY Ry rY ry RY Ry rY ry
RY Ry rY ry

10. B) Identify how dihybrid crosses support independent assortment
Phenotypic ratio:
9:3:3:1
Round/Yellow: 9
Dom/Dom
Round/green: 3
Dom/Rec
wrinkled/Yellow: 3
Rec/Dom
wrinkled/green: 1
Rec/Rec RY Ry rY ry
RRYY
RRYy
RrYY
RrYy
RRyy
Rryy
rrYY
rrYy
rryy

11. What Do the Peas Look Like?
Obj. B) Identify how dihybrid crosses support independent assortment

12. A. TG, TG, tG, tG B. tY, tY, tY, tY C. TR, Tr, TR, Tr
Obj. C) Complete punnett squares for two trait crosses
Gamete identification practice.
Given the following genotypes of a parent, identify the four gametes they will produce.
TtGG
ttYY
TTRr
A. TG, TG, tG, tG
B. tY, tY, tY, tY
C. TR, Tr, TR, Tr

13. TP TTPP TTPP TTPP TTPP Tp TTPp TTPp TTPp TTPp tP TtPP TtPP TtPP TtPP
Obj. C) Complete punnett squares for two trait crosses
Complete the following cross: T = tall, t = short P = purple flowers, p = white flowers Cross a Homozygous tall purple-flowered pea plant with a completely heterozygous pea plant
TTPP x TtPp TP TP TP TP TP
TTPP
TTPP
TTPP
TTPP
Phenotypic ratio:
100% Tall/Purple Tp
TTPp TTPp TTPp TTPp tP
TtPP TtPP TtPP TtPP tp
TtPp TtPp TtPp TtPp

14. Obj. D) Summarize Mendel’s three laws
PARENT CROSS
OFFSPRING
P Gen
TT x tt tall x short
100% Tt tall
DOMINANCE
SEGREGATION
F1 Gen
Tt x Tt tall x tall
75% tall 25% short
Dihybrid Cross
RrGg x RrGg round & green x round & green
INDEPENDENT ASSORTMENT
9/16 Dom/Dom 3/16 Dom/Rec 3/16 Rec/Dom 1/16 Rec/Rec

15. Leopard Geckos
India, Pakistan, Afghanistan
About $20

16. RAPTAR Leopard Gecko 6 Phenotypes
A Ruby-Red Eyes
Carrot-head
Carrot-tail
Hypo Tangerine
Patternless
Tremper Albino

17. Punnet Square 8 alleles for 6 Phenotypes
RAPTAR
1/64

18. RAPTAR Leopard Gecko
April 2006 $1,000
April 2011 $700

19. Understanding Check: Two Trait Crosses: T = Tall, t = Short
R = Round, r = wrinkled
Identify how many offspring are predicted to possess each of the 4 possible phenotypes.
You must show your work.
Cross a TTrr X ttRR
Cross parent 1 who is heterozygous for both traits with parent 2 who is short and wrinkled.