1. Warm-up
Complete these crosses. Give the possible genotypic results and phenotypic results.
Free ear lobes are dominant to attached ear lobes in humans.  If a recessive male marries a homozygous dominant female, what will be the phenotypic and genotypic ratios of their offspring?
Give the phenotypic and genotypic ratios of the possible offspring produced, when a heterozygous brown-eyed man marries a heterozygous brown-eyed woman.  Brown eyes are dominant over blue eyes which are recessive.

2. Agenda Warm-up Notes Practice Worksheets Whiteboards Clean-Up
Cool-down

3. Announcements
Quiz Tuesday Punnett Squares.

4. Genetics Part II

5. each trait is inherited independent of other traits (chance)
Independent Assortment
each trait is inherited independent of other traits (chance)

6. Segregation
in meiosis two alleles separate so that each gamete (sex cell) receives only one form of the gene from each parent

8. Mendel’s Principles of Inheritance
Inherited traits are transmitted by genes which occur in alternate forms called alleles
Principle of Dominance - when 2 forms of the same gene are present the dominant allele is expressed
Principle of Segregation - in meiosis two alleles separate so that each gamete receives only one form of the gene
Principle of Independent Assortment - each trait is inherited independent of other traits (chance)

9. If we saw an organism that had round seeds (round is dominant), how could we figure out what its genotype is?

10. TEST CROSS!

11. A cross between an unknown and a homozygous recessive
Test Cross
A cross between an unknown and a homozygous recessive

12. Example of a Test Cross
Unknown

13. Incomplete Dominance
When a combination of the dominant and recessive creates a new phenotype. RR = red rr = white Rr = pink

14. Incomplete Dominance-When an intermediate between the dominant and recessive is expressed

15. Incomplete Dominance RR Rr rr

16. Incomplete Dominance Cross

17. Incomplete Dominance Cross

18. Polygenic Trait
Polygenic traits are traits that are influenced by several genes. Examples include human height and skin color, which are both influenced by dozens of genes.
As a result of polygenic traits, a lot of intermediate conditions exist.
Genes with 3 or more alleles have multiple alleles. An example of multiple alleles is blood (IA, IB, IO)

19. Blood Type
The four Blood types are: A, B, AB, and O that come from the three alleles IA, IB, IO
A and B are codominant, and they are also dominant to O.
Type A = IAIA or IAIO, Type B = IBIB or IBIO, Type AB = IA IB, and Type O = IOIO

20. Codominance-neither allele is dominant, but both are expressed at the same time

21. IT’S A MUST
When a combination of the dominant and recessive allele make a new intermediate trait...

22. Incomplete dominance

23. Situation where neither allele is dominant, but both are expressed at the same time

24. codominance

25. What is a cross between an unknown and a homozygous recessive?

26. Test cross

27. What are the possible genotypes of Type A blood?

28. IAIA or IAIO

29. Draw the punnett square of the cross between a male with Type AB blood and a female with Type O blood.

30. What is the genotypic and phenotypic ratio of the cross?

31. 2 IAIO: 2 IBIO
2 type A blood : 2 type B blood

32. Draw the cross and give the genotypic and phenotypic ratios of the cross of a red flower and a pink flower.
Red- hom. dom
Pink- het.
White- hom. rec.

33. You found a tall pea plant
You found a tall pea plant. Explain how you would determine the genotype of this plant.
*Hint in pea plants, short height is recessive.
What are the possible genotypes of the plant?
b. Draw Punnett squares for your possible crosses.
c. You have 24 offspring, 24 tall and 0 short plants. What was the genotype of the plant?

34. THANK YOU!! Clean up this room!! That means…
No paper or trash on the floor
Chairs tucked under the desks
Desks straight
THANK YOU!!

35. Cool-Down
1- Give an example of a phenotype and a genotype. 2- What is the difference between homozygous and heterozygous? 3- Perform a cross with RR x rr? What % of offspring would express the dominant trait?