1. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu To View the presentation as a slideshow with effects select “View” on the menu bar and click on “Slide Show.” To advance through the presentation, click the right-arrow key or the space bar. From the resources slide, click on any resource to see a presentation for that resource. From the Chapter menu screen click on any lesson to go directly to that lesson’s presentation. You may exit the slide show at any time by pressing the Esc key. How to Use This Presentation

2. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter Presentation Transparencies Standardized Test Prep Visual Concepts Resources

3. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Inheritance Patterns and Human Genetics Chapter 12 Table of Contents Section 1 Chromosomes and Inheritance Section 2 Human Genetics

4. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 12 Objectives Distinguish between sex chromosomes and autosomes. Explain the role of sex chromosomes in sex determination. Describe how an X- or Y-linked gene affects the inheritance of traits. Explain the effect of crossing-over on the inheritance of genes in linkage groups. Distinguish between chromosome mutations and gene mutations. Section 1 Chromosomes and Inheritance

5. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 12 Chromosomes Genes reside on chromosomes. Section 1 Chromosomes and Inheritance

6. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 12 Chromosomes, continued Sex Chromosomes and Autosomes –Sex chromosomes contain genes that determine an organism’s sex (gender). –The remaining chromosomes that are not directly involved in determining the sex of an individual are called autosomes. Section 1 Chromosomes and Inheritance

7. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 12 Karyotypes: Male and Female Section 1 Chromosomes and Inheritance

8. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 12 Chromosomes, continued Sex Determination –In mammals, an individual carrying two X chromosomes is female. –An individual carrying an X and a Y chromosome is male. Section 1 Chromosomes and Inheritance

9. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 12 Effects of Gene Location Sex-Linked Genes and Traits –Genes found on the X chromosome are X-linked genes. –A sex-linked trait is a trait whose allele is located on a sex chromosome. –Because males have only one X chromosome, a male who carries a recessive allele on the X chromosome will exhibit the sex-linked trait. Section 1 Chromosomes and Inheritance

10. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 12 Effects of Gene Location, continued Linked Genes –Pairs of genes that tend to be inherited together are called linked genes. Section 1 Chromosomes and Inheritance

11. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 12 Effects of Gene Location, continued Chromosome Mapping –The farther apart two genes are located on a chromosome, the more likely a cross-over will occur. –Researchers use recombinant percentages to construct chromosome maps showing relative gene positions. Section 1 Chromosomes and Inheritance

12. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 12 Mutations Germ-cell mutations occur in gametes and can be passed on to offspring. Somatic-cell mutations occur in body cells and affect only the individual organism. Section 1 Chromosomes and Inheritance

13. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 12 Mutations, continued Chromosome Mutations –Chromosome mutations are changes in the structure of a chromosome or the loss or gain of an entire chromosome. Section 1 Chromosomes and Inheritance

14. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 12 Chromosomal Mutations Section 1 Chromosomes and Inheritance

15. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 12 Mutations, continued Gene Mutations –Gene mutations are changes in one or more of the nucleotides in a gene. Section 1 Chromosomes and Inheritance

16. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 12 Gene Mutations Section 1 Chromosomes and Inheritance

17. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Human Genetics Chapter 12 Objectives Analyze pedigrees to determine how genetic traits and genetic disorders are inherited. Summarize the different patterns of inheritance seen in genetic traits and genetic disorders. Explain the inheritance of ABO blood groups. Compare sex-linked traits with sex-influenced traits. Explain how geneticists can detect and treat genetic disorders.

18. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Human Genetics Chapter 12 Inheritance of Traits Pedigrees –Geneticists use pedigrees to trace diseases or traits through families. –Pedigrees are diagrams that reveal inheritance patterns of genes.

19. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 12 Pedigree for Cystic Fibrosis Section 2 Human Genetics

20. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Chapter 12 Some Important Genetic Disorders Section 2 Human Genetics

21. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Human Genetics Chapter 12 Genetic Traits and Disorders Polygenic Inheritance –Polygenic characters, such as skin color, are controlled by two or more genes.

22. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Human Genetics Chapter 12 Genetic Traits and Disorders, continued Complex Characters –Complex characters, such as polygenic traits, are influenced by both genes and environment.

23. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Human Genetics Chapter 12 Genetic Traits and Disorders, continued Multiple Alleles –Multiple-allele characters, such as ABO blood groups, are controlled by three or more alleles of a gene.

24. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Human Genetics Chapter 12 Genetic Traits and Disorders, continued X-Linked Traits –The gene for colorblindness, an X-linked recessive gene, is found on the X chromosome.

25. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Human Genetics Chapter 12 Genetic Traits and Disorders, continued Sex-influenced Trait –A sex-influenced trait, such as pattern baldness, is expressed differently in men than in women even if it is on an autosome and both sexes have the same genotype.

26. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Human Genetics Chapter 12 Detecting Genetic Disease Genetic screening examines a person’s genetic makeup and potential risks of passing disorders to offspring. Amniocentesis and chorionic villi sampling help physicians test a fetus for the presence of genetic disorders.

27. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Human Genetics Chapter 12 Detecting Genetic Disease, continued Genetic Counseling –Genetic counseling informs screened individuals about problems that might affect their offspring.

28. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Human Genetics Chapter 12 Treating Genetic Disease Genetic disorders are treated in various ways. Among the treatments are symptom-relieving treatments and symptom-prevention measures, such as insulin injections for diabetes.

29. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Section 2 Human Genetics Chapter 12 Treating Genetic Disease, continued Gene Therapy –In gene therapy, a defective gene is replaced with a copy of a healthy gene. –Somatic cell gene therapy alters only body cells. –Germ cell gene therapy attempts to alter eggs or sperm.

30. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice 1. Which can a chromosomal map show? A. the sex of the individual B. the presence of mutant alleles C. the positions of genes on a chromosome D. whether a gene is autosomal or recessive Standardized Test Prep Chapter 12

31. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 1. Which can a chromosomal map show? A. the sex of the individual B. the presence of mutant alleles C. the positions of genes on a chromosome D. whether a gene is autosomal or recessive Standardized Test Prep Chapter 12

32. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 2. Which can result from the deletion of a single nucleotide? F. trisomy G. a translocation H. nondisjunction J. a frameshift mutation Standardized Test Prep Chapter 12

33. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 2. Which can result from the deletion of a single nucleotide? F. trisomy G. a translocation H. nondisjunction J. a frameshift mutation Standardized Test Prep Chapter 12

34. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 3. At the present time amniocentesis cannot reveal which of the following? A. eye color B. genetic disease C. sex of the fetus D. chromosomal abnormalities Standardized Test Prep Chapter 12

35. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 3. At the present time amniocentesis cannot reveal which of the following? A. eye color B. genetic disease C. sex of the fetus D. chromosomal abnormalities Standardized Test Prep Chapter 12

36. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 4. A geneticist working with the fruit fly Drosophila melanogaster discovers a mutant phenotype that appears only in males who are offspring of males of the same phenotype. What does this information suggest about the mutant phenotype? F. The trait is X-linked. G. The trait is Y-linked. H. The trait is autosomal dominant. J. The trait is autosomal recessive. Standardized Test Prep Chapter 12

37. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 4. A geneticist working with the fruit fly Drosophila melanogaster discovers a mutant phenotype that appears only in males who are offspring of males of the same phenotype. What does this information suggest about the mutant phenotype? F. The trait is X-linked. G. The trait is Y-linked. H. The trait is autosomal dominant. J. The trait is autosomal recessive. Standardized Test Prep Chapter 12

38. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 5. Which statement best explains why men and women express the Bb genotype differently? A. The trait is polygenic. B. The trait has multiple alleles. C. Pattern baldness is a sex-linked trait. D. Pattern baldness is a sex-influenced trait. Chapter 12 The table below shows the genotypes and phenotypes of pattern baldness. Use the table to answer the question that follows. Standardized Test Prep

39. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 5. Which statement best explains why men and women express the Bb genotype differently? A. The trait is polygenic. B. The trait has multiple alleles. C. Pattern baldness is a sex-linked trait. D. Pattern baldness is a sex-influenced trait. Chapter 12 The table below shows the genotypes and phenotypes of pattern baldness. Use the table to answer the question that follows. Standardized Test Prep

40. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 6. translocation : chromosome mutation :: substitution F. gene mutation G. point mutation H. germ-cell mutation J. somatic-cell mutation Chapter 12 Standardized Test Prep

41. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 6. translocation : chromosome mutation :: substitution F. gene mutation G. point mutation H. germ-cell mutation J. somatic-cell mutation Chapter 12 Standardized Test Prep

42. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 7. Which type of inheritance pattern is associated with hemophilia? A. autosomal recessive B. sex-linked dominant C. sex-linked recessive D. autosomal dominant Chapter 12 The image below is a pedigree showing the inheritance of hemophilia in a family. Use the pedigree to answer the question that follows. Standardized Test Prep

43. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Multiple Choice, continued 7. Which type of inheritance pattern is associated with hemophilia? A. autosomal recessive B. sex-linked dominant C. sex-linked recessive D. autosomal dominant Chapter 12 The image below is a pedigree showing the inheritance of hemophilia in a family. Use the pedigree to answer the question that follows. Standardized Test Prep

44. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Short Response Consider a couple about to get married. The woman has cystic fibrosis, but the man does not. What benefit would they gain by seeing a genetic counselor? Chapter 12 Standardized Test Prep

45. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Short Response, continued Consider a couple about to get married. The woman has cystic fibrosis, but the man does not. What benefit would they gain by seeing a genetic counselor? Answer: Genetic counseling will tell them the likelihood of each of their children having cystic fibrosis or carrying the cystic fibrosis gene. Chapter 12 Standardized Test Prep

46. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Extended Response Colorblindness is a recessive, sex-linked trait. A woman and a man, both with normal vision, have three daughters with normal vision. One of the daughters marries a man with normal vision, and they have a son who is colorblind. Part A Which parent of the son is the carrier of the trait? Explain your answer. Part B What is the likelihood that the children of a woman heterozygous for colorblindness and colorblind man will express the trait? Explain your answer. Chapter 12 Standardized Test Prep

47. Copyright © by Holt, Rinehart and Winston. All rights reserved. ResourcesChapter menu Extended Response, continued Answer: Part A The son’s mother carries the trait. The gene for colorblindness is carried on the X chromosome. Part B Given: X-linked recessive: heterozygous female = X B (normal)X b (colorblind); colorblind male = X b (colorblind)Y. This Punnett square predicts that 50 percent of the children will be male and 50 percent of the children will be female. 50 percent will be colorblind and 50 percent will have normal vision. 25 percent will be males with normal vision and will not be carriers. 25 percent will be female carriers with normal vision. 25 percent will be colorblind females. 25 percent will be colorblind males. Chapter 12 Standardized Test Prep