2. Click on a lesson name to select. Section 7.1: Chromosomes and Phenotipe Section7. 2: Complex Patterns of Inheritance Section 7.3: Chromosomes and Human Heredity Ch. 7 Extending Mendelian Genetics

3. Complex Inheritance and Human Heredity Pedigrees  A diagram that traces the inheritance of a particular trait through several generations Basic Patterns of Human Inheritance

4. Complex Inheritance and Human Heredity Inferring Genotypes  Knowing physical traits can determine what genes an individual is most likely to have. Predicting Disorders  Record keeping helps scientists use pedigree analysis to study inheritance patterns, determine phenotypes, and ascertain genotypes. Basic Patterns of Human Inheritance

5. Complex Patterns of Inheritance Complex Inheritance and Human Heredity Incomplete Dominance  The heterozygous phenotype is an intermediate phenotype between the two homozygous phenotypes.

6. Complex Inheritance and Human Heredity Codominance  Both alleles are expressed in the heterozygous condition. Complex Patterns of Inheritance  Sickle-cell disease is one example.

7. Complex Inheritance and Human Heredity Sickle-cell Disease  Changes in hemoglobin cause red blood cells to change to a sickle shape.  People who are heterozygous for the trait have both normal and sickle-shaped cells. Sickle cell Normal red blood cell 7766x Complex Patterns of Inheritance

8. Complex Inheritance and Human Heredity Multiple Alleles  Blood groups in humans  ABO blood groups have three forms of alleles. Complex Patterns of Inheritance

9. Complex Inheritance and Human Heredity Coat Color of Rabbits  Multiple alleles can demonstrate a hierarchy of dominance.  In rabbits, four alleles code for coat color: C, c ch, c h, and c. Complex Patterns of Inheritance

10. Complex Inheritance and Human Heredity Epistasis  Variety is the result of one allele hiding the effects of another allele. Complex Patterns of Inheritance

11. Complex Inheritance and Human Heredity Sex Determination  Sex chromosomes determine an individual’s gender. Complex Patterns of Inheritance

12. Complex Inheritance and Human Heredity Dosage Compensation  The X chromosome carries a variety of genes that are necessary for the development of both females and males.  The Y chromosome mainly has genes that relate to the development of male characteristics.  In females, one X chromosome is inactivated in each cell. The inactivated X chromosome is visible in stained cells as a Barr body. Complex Patterns of Inheritance

13. Complex Inheritance and Human Heredity Sex-Linked Traits  Genes located on the X chromosome  Red-green color blindness  Hemophilia Complex Patterns of Inheritance

14. Complex Inheritance and Human Heredity Polygenic Traits  Polygenic traits arise from the interaction of multiple pairs of genes. Complex Patterns of Inheritance

15. Complex Inheritance and Human Heredity Environmental Influences  Environmental factors influence an organism’s phenotype  Diet and exercise  Sunlight and water  Temperature Complex Patterns of Inheritance

16. Complex Inheritance and Human Heredity Twin Studies  Helps scientists separate genetic contributions from environmental contributions  Traits that appear frequently in identical twins are at least partially controlled by heredity.  Traits expressed differently in identical twins are strongly influenced by environment. Complex Patterns of Inheritance

17.  Karyotype—micrograph in which the pairs of homologous chromosomes are arranged in decreasing size. Chromosomes and Human Heredity Complex Inheritance and Human Heredity Karyotype Studies  Images of chromosomes stained during metaphase  Chromosomes are arranged in decreasing size to produce a micrograph.

18. Complex Inheritance and Human Heredity Telomeres  Telomere caps consist of DNA associated with proteins.  Serves a protective function for the structure of the chromosome Chromosomes and Human Heredity

19. Complex Inheritance and Human Heredity Nondisjunction  Cell division during which sister chromatids fail to separate properly  Down syndrome, also called trisomy 21 Chromosomes and Human Heredity

20. 1.A 2.B 3.C 4.D CDQ 3 Complex Inheritance and Human Heredity Chapter Chapter Diagnostic Questions Under what circumstances will a recessive trait be expressed? A. A recessive allele is passed on by both parents. B. One parent passes on the recessive allele. C. The individual is heterozygous for the trait. D. There is a mutation in the dominant gene.

21. 1.A 2.B 3.C 4.D FQ 2 Complex Inheritance and Human Heredity Chapter A. DD B. Dd C. dd D. dE Which is the genotype of a person who is a carrier for a recessive genetic disorder? Section 1 Formative Questions

22. 1.A 2.B 3.C 4.D FQ 3 Complex Inheritance and Human Heredity Chapter Section 1 Formative Questions A. at least one parent is a carrier B. both parents are carriers C. both parents are homozygous recessive D. at least one parent is homozygous dominant Albinism is a recessive condition. If an albino squirrel is born to parents that both have normal fur color, what can you conclude about the genotype of the parents?

23. 1.A 2.B 3.C 4.D FQ 4 Complex Inheritance and Human Heredity Chapter A. dosage compensation B. incomplete dominance C. multiple alleles D. sex-linked When a homozygous male animal with black fur is crossed with a homozygous female with white fur, they have offspring with gray fur. What type of inheritance does this represent? Section 2 Formative Questions

24. 1.A 2.B 3.C 4.D FQ 5 Complex Inheritance and Human Heredity Chapter Section 2 Formative Questions A. autosomes B. Barr bodies C. monosomes D. sex chromosomes Of the 23 pairs of chromosomes in human cells, one pair is the _______.

25. 1.A 2.B 3.C 4.D FQ 6 Complex Inheritance and Human Heredity Chapter Section 2 Formative Questions A. blood type B. color blindness C. hemophilia D. skin color Which is an example of a polygenic trait?

26. 1.A 2.B 3.C 4.D FQ 7 Complex Inheritance and Human Heredity Chapter A. The blood type of an individual. B. The locations of genes on a chromosome. C. The cell’s chromosomes arranged in order. D. The phenotype of individuals in a pedigree. What does a karyotype show? Section 3 Formative Questions

27. 1.A 2.B 3.C 4.D FQ 8 Complex Inheritance and Human Heredity Chapter Section 3 Formative Questions A. multiple alleles B. nondisjunction C. nonsynapsis D. trisomy What is occurring in this diagram?

28. 1.A 2.B 3.C 4.D FQ 9 Complex Inheritance and Human Heredity Chapter Section 3 Formative Questions A. Down syndrome B. Klinefelter’s syndrome C. Tay-Sachs syndrome D. Turner’s syndrome What condition occurs when a person’s cells have an extra copy of chromosome 21?

29. 1.A 2.B 3.C 4.D CAQ 1 Complex Inheritance and Human Heredity Chapter A. 1 and 2 are siblings B. 1 and 2 are parents C. 1 and 2 are offspring D. 1 and 2 are carriers What does the top horizontal line between numbers 1 and 2 in the figure indicates? Chapter Assessment Questions

30. 1.A 2.B 3.C 4.D CAQ 2 Complex Inheritance and Human Heredity Chapter Chapter Assessment Questions A. I A B. I O C. I B D. i Which is not an allele in the ABO blood group?

31. 1.A 2.B 3.C 4.D CAQ 3 Complex Inheritance and Human Heredity Chapter Chapter Assessment Questions A. one less chromosome on pair 12 B. one extra chromosome on pair 21 C. one less chromosome on pair 21 D. one extra chromosome on pair 12 Down Syndrome results from what change in chromosomes?

32. 1.A 2.B 3.C STP 1 Complex Inheritance and Human Heredity Chapter A. heterozygous B. homozygous dominant C. homozygous recessive If a genetic disorder is caused by a dominant allele, what is the genotype of those who do not have the disorder? Standardized Test Practice

33. 1.A 2.B 3.C STP 2 Complex Inheritance and Human Heredity Chapter Standardized Test Practice A. RR B. Rr C. rr Analyze this pedigree showing the inheritance of a dominant genetic disorder. Which would be the genotype of the first generation father?

34. 1.A 2.B 3.C 4.D STP 3 Complex Inheritance and Human Heredity Chapter Standardized Test Practice A. codominance B. dosage compensation C. epistasis D. sex-linked Shorthorn cattle have an allele for both red and white hair. When a red-haired cow is crossed with a white-haired bull, their calf has both red and white hairs scattered over its body. What type of inheritance does this represent?

35. 1.A 2.B 3.C 4.D STP 4 Complex Inheritance and Human Heredity Chapter Standardized Test Practice A. Males have only one X chromosome. B. Males have two X chromosomes. C. Males have only one Y chromosome. D. The traits are located on the Y chromosomes. Why are males affected by recessive sex-linked traits more often than are females?

36. 1.A 2.B 3.C 4.D STP 5 Complex Inheritance and Human Heredity Chapter Standardized Test Practice A. 25% B. 50% C. 75% D. 100% A carrier of hemophilia and her husband, who is unaffected by the condition, are expecting a son. What is the probability that their son will have hemophilia?