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Create a gene and a corresponding allele on your whiteboard Gene: _____________ Allele: ________, _________ Alleles (variations of trait) -Purple, blue,

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Presentation on theme: "Create a gene and a corresponding allele on your whiteboard Gene: _____________ Allele: ________, _________ Alleles (variations of trait) -Purple, blue,"— Presentation transcript:

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3 Create a gene and a corresponding allele on your whiteboard Gene: _____________ Allele: ________, _________ Alleles (variations of trait) -Purple, blue, white -curly, straight, wavy -Short, tall Gene (trait) -Flower Color -Hair type -Plant Height

4  Phenotype  Physical appearance terms  ex. Tall, short, brown hair etc.  Genotype  Genes in cell, written with letters that represent the genes (ex: “T” for tall, or “t” for short)

5 Punnett Squares: diagram that determines the probable distribution of inherited traits in the offspring. UPPERCASE letters are used to represent dominant genes (traits). lowercase letters are used to represent recessive genes (traits).

6 Homozygous: Both alleles are the same. Either both capitols (dominant) or both lower-cased (recessive) Example: BB (homozygous dominant) bb (homozygous recessive) Heterozygous: Both alleles are different. One capital letter and one lower-cased letter. Example:Bb

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8 1. RR= 2. Ll= 3. Yy 4. Ee

9 1. A fish is homozygous recessive for fin color 2. A cat is heterozygous for tail length. 3. A turtle is homozygous dominant for shell color. 4. A polar bear is homozygous recessive for claw length.

10 Sample Problem T represents the gene for TALL in pea plants t represents the gene for short in pea plants So: TT & Tt both result in a TALL plant, because T is dominant over t. t is recessive. What will tt result in? Remember there are two genes for every trait!

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12  Write the 3 possible genotypes and phenotypes for the following:  Green eyes are dominant to blue eyes  (use the first letter of the dominant trait)  GG=  Gg=  gg=

13  Write the 3 possible genotypes and phenotypes for the following:  Curled toes are dominant to straight toes  (use the first letter of the dominant trait)  CC=  Cc=

14 Let’s cross a homozygous tall plant (TT) with a short plant (tt). Each plant will give only one of its’ two genes to the offspring. TT x tt TTtt

15 TTtt Each gene (allele) separates from the other so that the offspring get only one gene from each parent for a given trait. TTtt TT x t t

16  Predict the offspring if a tall plant (TT) is crossed (mates) with a short plant (tt) TT x tt

17 TtTtTt t The genes from one parent go here. The genes from the other parent go here.

18 TT tTtTtTt t

19 TT t t If a box receives a capital letter and a lower- cased letter we write the capitol letter first

20 Possible offspring Genotype =

21 Possible offspring Genotype = Tt.

22 What percent of offspring will have the following genotypes: TT= Tt= tt=

23 Possible offspring Genotype = Tt. What percent of offspring will have the following genotypes: TT= 0% Tt= 100% tt= 0%

24 Possible offspring Genotype = Tt. What percent of offspring will have the following genotypes: TT= 0% Tt= 100% tt= 0% Possible offspring phenotype =

25 Possible offspring Genotype = Tt. What percent of offspring will have the following genotypes: TT= 0% Tt= 100% tt= 0% Possible offspring phenotype = tall.

26 Possible offspring Genotype = Tt. What percent of offspring will have the following genotypes: TT= 0% Tt= 100% tt= 0% Possible offspring phenotype = tall. What percent of offspring will have the following phenotypes: Tall= Short=

27 Possible offspring Genotype = Tt. What percent of offspring will have the following genotypes: TT= 0% Tt= 100% tt= 0% Possible offspring phenotype = tall. What percent of offspring will have the following phenotypes: Tall= 100% Short= 0%

28 Black rabbits are dominant to brown. Two heterozygous rabbits have offspring. Predict what percentage of their offspring will be brown.

29 Step 1: Determine the genotype of parents. Always use the first letter of the dominant trait. ____________x _____________

30 Black rabbits are dominant to brown. Two heterozygous rabbits have offspring. Predict what percentage of their offspring will be brown. Step 1: Determine the genotype of parents. Always use the first letter of the dominant trait. ____________x _____________

31 Step 2: Set up a Punnett Square

32 Step 3: Complete Punnett Square

33 Step 4: Predict offspring phenotype.

34 Black rabbits are dominant to brown. Two heterozygous rabbits have offspring. Predict what percentage of their offspring will be brown?

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36  Tall plants are dominant to short. Cross two heterozygous pea plants. 1. Determine parent’s genotype and write on whiteboard Your Turn!!

37  Set up a punnett square and fill it in.  Hold up whiteboard

38 Tt TTTTt t tt

39  Determine the genotype percentages and write on whiteboard  TT=  Tt=

40 Tt TTTTt t tt Genotype percentage : TT – 25%

41 Tt TTTTt t tt Genotype percentage: TT – 25%, Tt – 50%

42 Tt TTTTt t tt Genotype percentage: TT – 25%, Tt – 50%, tt – 25%

43  Determine the Phenotype percentages and write on whiteboard  Tall=  Short=

44 Tt TTTTt t tt Genotype percentage: TT – 25%, Tt – 50%, tt – 25% Phenotype percentage: Tall – 75%

45 Tt TTTTt t tt Genotype percentage: TT – 25%, Tt – 50%, tt – 25% Phenotype percentage: Tall – 75%, short – 25%

46 Round seeds are dominant to wrinkled seeds.  Rr x rr What percentage of the offspring will be round? _______________

47  Classwork: Punnett Packet Pages 1-?  Homework: Punnett Packet Pages ?-? (due tomorrow)


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