1 Heredity Holt Biology Chapter 8, pgs By Bettina Loell-Hull

2 Anticipatory Set

4 Studying Heredity Using the Punnett Square

Compare and Contrast the Twins Same parents Each parent has 1 allele for light & 1 allele dark skin. Each parent has 1 brown & 1 blue allele for eye color. fraternal twins 1-dark skin (1 or 2 allele(s) for dark skin 2-brown eyes (1 or 2 allele(s) for brown eyes) 1-light skin (2 alleles for light skin) 2-blue eyes (2 alleles for blue eyes) 3-brown hair (1 or 2 allele(s) for brown hair) 3-blond hair (2 alleles for blond hair) Each parent has 1 allele for brown hair & 1 allele for blond hair.

6 Anticipatory Set

7 Heredity and Eye Color

8 The Punnett Square Calculates the Possibilities of the Children’s Looks Bb BBBBbBb bBbBbbb Mother Father

9 Odds of Dark Hair vs. White Hair

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11 Homozygous cross and Heterozygous Cross

12 Standard 3a: Students know how the genotypes of the parents may be expressed as phenotypes in their offspring. Students relate the ratios that Mendel observed in his crosses to his data and to examples of their own. Phenotype (F1 generation 100 % = 4/4) Phenotype (F2 generation 75% to 25% = 3/1)

13 1.dominant2. recessive3. phenotype 4. genotype5. monohybrid cross 6. homozygous 7. heterozygous8. allele9. Punnett square

14 1. Dominant (adjective) Expressed form of the character trait. For example the color of a flower may be purple and not white because purple is dominant.

15 2. Recessive (adjective) The trait that is not expressed when the dominant form of the trait is present. Ex.: In this case, the baby has blue eyes because she has two recessive alleles for blue eyes.

16 3 Phenotype (noun) A phenotype is a living thing’s appearance or other detectable characteristic that results from the living thing’s genotype and the environment. For example: the color of a flower or seed

17 4 Genotype (noun) The entire genetic makeup of an organism- its DNA Or the combination of genes for one specific trait. For example, the color of the seed pod is green but the genetic make-up of it is yellow and green.

18 5-Monohybrid Cross (noun) A cross in which each parent displays a different form of one allele. For example: seed color (YY or yy)

19 6-Homozygous (adjective) Describes an individual that has identical alleles for a trait on both gametes. Example: PP or pp for color of flower.

20 7-Heterozygous (adjective) Describes an individual that has two different alleles for a trait. For example, a flower may look purple but has the alleles Pp for flower color.

21 8-Allele (noun) An allele is one of the alternative forms of a gene that determines a characteristic, such as hair color. Example: the alleles for hair color may be black or blond.

22 9-Punnett Square (noun) A Punnett square is a graphic representation used to predict the chances that the offspring will inherit an allele for a trait. What are the chances of a yellow offspring if yellow is dominant? 100%

1-Dominant A-Describes an individual who has two different alleles for a trait. 2-Recessive B-graphic representation used to predict chances of offspring to inherit allele of a trait 3-phenotype C- The trait that is not expressed when the dominant form of the character is present. 4-genotype D- Describes individual with identical alleles for a trait. 5-monohybrid cross E- the combination of genes for one specific trait. 6-homozygous F- a thing’s or person’s appearance 7-heterozygous G- Expressed form of character trait. 8-allele H-A cross in which each parent displays a different form of one character trait. 9-punnett square I- one of the alternative forms of a gene.

24 Solution to Quiz 1G 2C 3F 4E 5H 6D 7A 8I 9B Home Video on Punnett Square

25 Video

26 Video on Heredity How to use the Punnett Square to Calculate the Odds of the Phenotype (looks) of Offspring Gregor Mendel's Rules of Heredity—Demonstration of impact that Parents Genotype has on Offspring’s Phenotype Using Punnett SquaresGregor Mendel's Rules of Heredity—Demonstration of impact that Parents Genotype has on Offspring’s Phenotype Using Punnett Squares

27 What did we learn from the video? We learned how to use the Punnett Square to calculate the odds of a certain phenotype in the offspring. We learned how to create a Monohybrid Cross 1. with homozygous parents 2. with heterozygous parents 1 2

28 Modeling 1

29 Monohybrid Cross – with Homozygous Bunny Parents ff F F f F Black is dominant Black FurWhite Fur 4/4=1=100%0/4=0=0%

30 Modeling 2

31 Monohybrid Cross (one trait) – with Heterozygous Bunny Parents Ff F F FF f f f Black is dominant Black FurWhite Fur ¾ = 75% =.75¼ = 25% =.25 Offspring’s Phenotype

32 Guided Practice 1

33 Monohybrid Cross – with Homozygous Parents who have blue eyes and brown eyes. b b B B b B Brown is dominant Brown EyesBlue Eyes 4/4 =100% =10/4=0%=0 Offspring’s Phenotype

34 Guided Practice 2

35 Monohybrid cross – with Heterozygous Parents Who both have Brown Eyes. Bb B B B B b b b b Brown is dominant Brown EyesBlue Eyes ¾ =75% =.75¼ =25% =.25 Offspring’s Phenotype

36 Independent Practice 1

Monohybrid cross with homozygous (BB or bb) parents Predict the phenotype of the offspring resulting from a cross of a white haired dog with a black haired dog. Make black hair (B) dominant and white hair (b) recessive. The white dog is homozygous recessive. The black dog is homozygous dominant. Write the gametes that each parent can. contribute as row and column labels. What does the offspring look like? State your answer in %, fraction, and decimals for each phonotype.

38 Monohybrid Cross – with Homozygous Parents (dogs) who have white fur and black fur. Black is dominant Offspring’s Phenotype Black Fur,x/4, %, x.xxWhite Fur x/4, %, x.xx

39 Monohybrid Cross – with Homozygous Parents (dogs) who have white fur and black fur. b b B B b B Black is dominant Black FurWhite Fur 4/4 = 100% =10/4 =0% =0 Offspring’s Phenotype

40 Independent Practice 2

Monohybrid cross with heterozygous (Bb and Bb) parents Predict the phenotype of the offspring of a cross of a black haired dog with a black haired dog (black hair is dominant that is why both dogs are black). Both dogs are heterozygous for hair color (Bb and Bb). Write the gametes that each parent can contribute as row and column labels. What does the offspring look like? State your answer in %, fraction, and decimals for each phonotype.

42 Monohybrid Cross – with Heterozygous Parents (dogs) who both have black fur. Black is dominant Offspring’s Phenotype Black Fur,x/4, %, x.xxWhite Fur x/4, %, x.xx

43 Monohybrid Cross – with Heterozygous Parents (dogs) who both have black fur. B b B B B B b b bb Black is dominant Black FurWhite Fur ¾ =75% =.75¼ =25% =.25 Offspring’s Phenotype

44 End of Lesson 1

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47 Release test question: ChCh c ChCh ChChChCh ChcChc cChcChccc C h c Produces offspring that is least likely to survive.

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49 Resources Types of Learners Video on Punnett Square and monohybrid crosses with homozygous parents and heterozygous parents. Gregor Mendel's Rules of Heredity— Demonstration of impact that Parents Genotype has on Offspring’s Phenotype Using Punnett Squares Holt Biology, chapter 8, pages