Chapter 12 Patterns Of Heredity And Human Genetics Answer Key

Presentation on theme: “Chapter 12 – Patterns of Heredity and Human Genetics”— Presentation transcript:

You are watching: Chapter 12 patterns of heredity and human genetics answer key

1 Chapter 12 – Patterns of Heredity and Human GeneticsObjectives Identify information presented on a karyotype Recognize the difference between male and female karyotypes Distinguish between normal and abnormal karyotypes

*

2 Take out a sheet of paper and write your name along with your lab partners.1. Look Figure on page 329. Explain what you think the picture is showing? 2. What do you think the numbers as well as letters on the photograph represent?

*

3 Karyotype pg. 329 Chromosomes come in pairs, inherited from parentsHalf from mom & half from dad Humans have 23 pairs of chromosomes, 46 total. Any more or less = abnormality Sex Chromosomes – Called X and Y Autosomes – all non-sex chromosomes

*

4 Karyotype Fig pg. 329 Picture of cell taken during the process of metaphase 3. Why metaphase? 4. Looking at the Figure 12.20, how are the chromosomes arranged? 5. Do you think male and female karyotypes are the same? Explain. Chromosomes arranged by length, banding pattern, centromere location Comparison against a normal karyotype

*

5

*

6

*

7 Pedigree Pedigree = map of inheritance of genetic traits from generation to generation

*

8 Symbols on a Pedigree Circle = Female Square = MaleShaded = Affected Unshaded = Unaffected Adjoining line = Married/Mating Connected by an adjoining line = Offspring Roman Numeral = Generation

*

9 Textbook pg. 310 Fig. 12.2 6. How many generations are shown?7. How many offspring did I-1 and I-2 have? 8. How many boys did III-3 and III-4 have? 9. How many girls did II-1 and II-2 have? 10. What kind of trait (dominant or recessive) is being passed down? 11. What genotypes must I-1 and I-2 be in order to have a child with this trait? 12.

See more: If And G(X) = 5X – 4, What Is The Domain Of ? The Functions F And G Are Defined As F(X) = 5X

See more: Flights From Guadalajara To Mexico City (Mex), Mexico City To Guadalajara Distance (Mex To Gdl)

What is the probability that they would have this type of child? Show a Punnett square

*

10 Recessive Heredity Caused by recessive allelesAttached earlobes, Cystic fibrosis (defective protein leads to excessive mucus production in lungs), Albinism Individual will only display the recessive phenotype if its genotype is homozygous recessive

*

11 Dominant Heredity Caused by dominant alleleFreckles, Widow’s peak, Hitchhickers thumb, Huntington’s disease (brain degeneration, doesn’t appear until later in age), immunity to poison ivy Individual will display the dominant phenotype if its genotype is heterozygous or homozygous dominant

*

12 When Heredity Follows Different RulesChapter 12, Section 2 pg. 315 Take out a sheet of paper and put your name along with your lab partners and answer the following questions.

*

13 Objectives Section 12.2 Distinguish between alleles for incomplete dominance and codominance Explain the patterns of multiple allele and polygenic inheritance Analyze the pattern of sex-linked inheritance Summarize how internal and external environments affect gene expression

*

14 Figure 12.7 pg. 316 1. Look at the figure and give 2 differences between this Punnett square and Mendelian Punnett squares. 2. What is the genotype for the red flowered snapdragon? White flowered? Pink? Red = RRWhite = R’R’Pink = RR’ 3. What phenotype is the result of crossing the red and white snapdragons? All Pink 4. How is this different than Mendelian genetics? (Tall x Short = )? A third phenotype possibility exists (Pink), not just red or white

*

15 Incomplete Dominance Incomplete Dominance = phenotype of a heterozygote is in between the dominant & recessive phenotypes, appearance of a third phenotype. No Longer Upper and Lowercase letters A or a Flowers known as Snapdragons come in 3 colors but have 2 alleles, R and R’. The ‘ is called prime. R’R’ = White R’R or RR’ = Pink RR = Red

*

16

*

17 Sample Problems – Show the Punnett SquaresCross the following snapdragons and give the genotype and phenotype ratios. 5. Red Flower x White Flower Phenotypic Ratio = 0Red : 4Pink : 0White Genotypic Ratio = 0 RR : 4R’R : 0 R’R’ 6. Pink Flower x Pink Flower Phenotypic Ratio = 1Red : 2Pink : 1White Genotypic Ratio = 1RR : 2R’R : 1R’R’ 7. White Flower x White Flower Phenotypic Ratio = 0 Red : 0 Pink : 4 White Genotypic Ratio = 0 RR : 0 R’R : 4 R’R’

*

18 Text pg. 316 Figure 12.7 Red x White = all pinkPink x Pink = 1Red: 2Pink: 1White

*

19 Genetics Review Mendelian Genetics – Simple Dominant & Recessive Traits (Tall TT or Tt or short tt) Incomplete Dominance – 3 phenotypes (FF = red, FF’ = pink, F’F’ = white) Pedigree – Map to show how traits are passed from parent to offspring (not shaded – doesn’t have trait, half shaded – carrier, shaded – has trait

*

20 Erminette Chickens This is an example of codominance.Looking at the feathers of the chicken below can you explain the meaning of codominance? How is the phenotype different than in incomplete dominance (hint: flower colors)?

*

21 Codominance pg. 323 Both alleles for a gene are expressed in a heterozygous individual You have 2 different letters for alleles – B & W Black Feathers FBFB = Black Feathers White Feathers FW FW = White When the 2 alleles are combined a chicken with both black and white feathers is created. Erminette chickens FBFW = Black & White Neither allele is dominant or recessive

*

22 Codominance Practice ProblemsCross a chicken that is homozygous for the black alleles with a chicken that is homozygous for the white alleles. 1.What color feathers did the offspring have? Cross 2 chickens from the F1 generation to make the F2 generation? 2.What color feathers did the offspring have?

*

23 Blood Types BLOOD TYPE.ppt

*

24 Sex Determination & Sex-linked InheritanceCombination of sex chromosomes (X and Y) determine an individual’s gender Males XY, X chromosome comes from mom & Y chromosome comes from dad Females XX, both mom & dad give an X chromosome Sex-linked Traits = traits controlled by genes on sex chromosomes

*

25

*

26 Red-Green colorblindnessHemophilia (blood doesn’t clot properly) Male Pattern Baldness Duchenne Muscular Distrophy (muscular degeneration leading to eventual paralysis)

*

27 Most of sex-linked traits are found on genes on the X chromosome (X-linked trait) because it is larger than the Y chromosome X-linked traits display more in males because they only have 1 X chromosome, whereas females get 2 X chromosomes so they can be carriers of the trait but not display the phenotype

*

28 Color Blindness – Recessive Trait B = Normal b = color blindMales XBY = NormalXbY = Color Blind Females XBXB = Normal XBXb = Carrier (Normal) XbXb = Color Blind Can males be carriers for color blindness? Why or why not?

*

29 Polygenic InheritanceCharacteristics that are influenced by several genes

*

Published

Leave a comment

Your email address will not be published. Required fields are marked *