Genetic Crosses
Punnett Squares
EAGLE ZONEImagine you are going to one of those super trendy
restaurants with lots of dishes that you’ve never heard of. Tell me how many different combinations of an entrée and
dessert can be ordered at the restaurant. Use the menu below.
The Chez Punnett MenuEntrees
Bikini Island Shrimp Wild and Crazy Trout Sweet Potato Gratin with Baby
Pinecones Cornish Hen in Free Range
Chicken Wrapped in Organic Turkey, Smothered in Genetically Modified Plum Sauce
Turkey Cream Puff Pie
Desserts Chocolate Mink
103 Layers Chocolate Cake Ecuadorian Pomegranate
Popsicles Avocado Gelato
Watermelon Croissants
Mathbench.umd.edu/modules/prob-stat_punnett-squares_intro/page14.htm
Demystify the Punnett Square
How many different combinations could you order?
Super-Trendy Restaurant Chez Punnett
Creating combos at Chez Punnett1. Bikini Shrimp
2. Wild and Crazy Trout
3. Pinecone Gratin
4. Plum Hen 5. Turkey Puff
1. Chocolate Mink
2. 1000 Layer Cake
3. Pom Popsicle
4. Avocado Gelato
5. Watermelon Croissant
Explore 1Dragon Punnett Squares http://www.tcet.unt.edu/tegs/chapter2/fires.html Complete the Dragon Punnett Squares as we explore the
interactive game.
Explore 2Predicting Outcomes of One Trait CrossesMonohybrid Punnett Squares
Complete the 1st Punnett Square; we will check together as a class
Eagle Zone Complete the “Making Predictions” pages
we worked on yesterday during class You have 20 minutes to complete the pages
before we begin notes The notes page is on the back of the
“making predictions” handout
Bb X BbPhenotypic Ratio
3:1Genotypic Ratio
1:2:1 B b
B
b
B B B b
b B b b
The Story of Mendel
The Gene Idea
Explain
Mendel and Genetics Using your handout, answer the questions
as we explain the concepts surrounding basic genetic
Terms to Know
Character (heritable feature, i.e., fur color)
Trait (variant for a character, i.e., brown)
P generation (parents) F1 generation (first filial generation)
Punnett square: Gene:
point on a chromosome that controls the trait
Allele: an alternate form of a gene A or a
Homozygous: identical alleles for a character
Heterozygous (Hybrid): different alleles for a gene
Phenotype: physical traits
Genotype: genetic makeup
Terms to Know
It All Began with Mendel (FYI) Gregor Mendel was born in 1822. Called the “Father of Genetics” Late 1800 chromosomes and the process of
meiosis were unknown. Mendel’s work was considered obscure and
unimportant until 1900 Walter Sutton proposed the Chromosome
Theory and people began to listen to his ideas.
Chromosome Theory – specific genes are located on specific chromosomes
Three Conclusions to His Research1. Principle of Dominance
and RecessivenessOne allele in a pair may mask the
effect of the other
2. Principle of SegregationThe two alleles for a characteristic
separate during the formation of eggs and sperm
3. Principle of Independent AssortmentThe alleles for different
characteristics are distributed to reproductive cells independently.
Elaborate 1 More Monohybrid Crosses
Elaborate 2 Meiosis Competition
Dad Mom
WWHh X wwHH
Using your sock chromosomes, demonstrate how the possible gametes are formed and write the correct all the possible gametes that can be formed on the board.
Guided Dihybrid Cross
Parents: --- -WWHh ---X -- wwHH
Gametes:- WH--- wH
WH - -wH
Wh wH
Wh wH
What about 2 Traits?BbTt x BbTt
BT Bt bT bt
BT BBTT BBTt BbTT BbTt
Bt BBTt BBtt BbTt Bbtt
bT BbTT BbTt bbTT bbTt
bt BbTt Bbtt bbTt bbtt
Evaluate Wanted:
Big Headed Bugs with Long Wings
Breeding Options Using head size and wing color as the
two traits, predict the outcomes following bug crosses.
Bug 1 X Bug 5----HhWW X hhww
Bug 2 X Bug 4----hhww X hhWw
Bug 3 X Bug 1----HhWw X HhWW