Understanding Inheritance Patterns and Genetic Disorders

1. Chapter 12 ReviewInheritance Patterns and Human Genetics Mutations and Genetic Disorders

2. Chapter 12 Handouts to Study • Vocabulary quiz • “Chapter 12 Notes” – Inheritance Patterns and Human Genetics (picture of karyotype on front) • “ Ch 12 Human Genetics Part 2” (picture of pedigree on front) • Problem Set: Sex-linked genes and Multiple Alleles ( Punnett Square problems) • Powerpoint Handout • Human Face Lab (patterns of inheritance: Complete Dominance, Incomplete Dominance, Polygenic, Epistasis) • Pedigree Practice • Genetic Disorders

3. Mutations DNA mutationsPoint (single nucleotide).Several types: when one nucleotide replaces another. Sometimes can be “silent” (no amino acids are changed. Sometimes causes problem—one amino is changed but that can cause a change in the whole protein. Substitution

4. DNA Mutations (cont’d) • When one nucleotide is added • When one nucleotide is removed. Both result in Insertion Deletion FrameshiftMutations

5. Chromosome Mutations Pieces of chromosomes break off and move. Deletion,Inversion,Translocation Inversion Translocation Deletion

6. karyotype This organized picture of an individual’s chromosomes is called a __________________ The person in this picture is a male female Female There are 2 X and no y chromosomes.

10. The genetic disorder in which the person can’t make the protein needed to make their blood clot is called ______________________ hemophilia Name an X-linked genetic disorder. Hemophilia, colorblindness, Muscular dystrophy

11. Genetic disorder in which a person can NOT breakdown phenylalanine and eating foods containing this amino acid causes them to become retarded. _________________ Phenylketonuria (PKU) A person with trisomy-21 (three #21 chromosomes) has ____________ Down syndrome

12. zygote The cell that forms when an egg and a sperm join together is called a _______________ TRUE or FALSE GERM cell mutations can be passed on to offspring. TRUE : Germ cells are reproductive cells. Changes in the DNA of these cells is passed on to the offspring.

13. polygenic A trait that is controlled by several genes (like skin color or height) is called ______________ TRUE or FALSE An autosomal trait is found on the X chromosome FALSE Autosomes are the chromosomes thatare NOT sex chromosomes.

14. Huntington’s disease is a genetic disease that causes a deterioration of brain tissue by middle age, sometimes after it has been passedto a person’s offspring. It is a mutation on chromosome 4. It shows up in both males and females. It shows up even when only one chromosome is defective. (HH or Hh). What type of disease? Autosomal dominant

15. Multiple allele A trait in which there are three or more choices for a single gene (like A, B, and O blood type) is a ____________ trait. polygenic multiple allele Eye color is a _____________ trait. Polygenic Multiple allele sex linked polygenic

16. SOMATIC A body cell is also called a ______________ cell. ______________ mutations cause deathoften before birth. LETHAL

17. A person with the Xy genotype would be male female male A _________ cell mutation happens in sperm or egg cells. GERM

18. MONOZYGOTIC or Identical Twins that come from one sperm and egg are called _____________ Which person shows that they have the trait (visible in their Phenotype)? A B A C

19. pedigree This picture shows a ___________________ Karyotype Pedigree Punnett square • X-linked genes _______________ • Only show up in females • Show up more frequently in males • can be heterozygous in males • only pass from mothers to daughters Show up more frequently in males

20. Which type of mutation can be passed along to offspring? Somatic cell mutation Germ cell mutation Germ cell mutation When homologous chromosomes don’t separate during meiosis it is called _________________ nondisjunction

21. father Which parent determines the sex of the baby? What is the difference between a germ cell mutation and a somatic cell mutation? Somatic cells are body cells and mutations in these cells are NOT passed on to offspring. Germ cells are reproductive cells. Mutations in these cells CAN be passed on to offspring.

22. TRUE TRUE or FALSE Females can be carriers for X linked genes Why do X-linked recessive disorders show up more in males than females? Males only have one X. If they get the gene it will show. Females have a 2nd X that can “hide” the disorder gene. They need 2 copies of the gene to show disorder. Males don’t have a “back up” X.

23. What disorder is it? Mutation in the blood clotting protein makes person unable to stop bleeding after an injury _______________ Mutation in hemoglobin causes red blood cells to change shape and ____________________ clog up blood vessels Mutation causes mental retardation if foods containing phenylalanine are eaten _____________________ Three #21 chromosomes are present causing mental retardation _______________________ Mutation in ion channel protein causesthick mucous to clog up lungs and digestive organs _______________________ Hemophilia Sickle cell anemia Phenylketonuria (PKU) Down syndrome Cystic fibrosis

24. What disorder is it? Gradual deterioration of the brainthat appears during middle age resulting in nursing home care and early death ____________________ Progressive weakening of muscleproteins resulting in inability to walkand eventually death _________________________ Inability to distinguish betweenthe colors red and green _____________________ Only one X and no y chromosome ____________________ resulting in infertility Huntington’s disease (HD) Duchenne Muscular dystrophy Colorblindness Turner syndrome

25. What disorder is it? Conjoined twins Twins that are born joined together ____________________ Males with an extra X chromosome ______________________(XXY) karyotype; some female features;infertility Lipids build up in brain causingblindness, retardation, & early death _________________________ Disorder in bone growth so torso __________________________ and head are normal size but armsand legs are short Klinefelter syndrome Tay-Sachs achondroplasia