Cells and Heredity

1. Cells and Heredity Chapter 4 Modern Genetics Section 1 Human Inheritance

2. Section 1 Human Inheritance: Objectives • To explain what multiple alleles are. • To explain why some human traits show a large variety of phenotypes. • To explain how environmental factors can alter the effects of a gene. • To explain what determines sex and why some sex linked traits are more common in males than in females. • To describe how geneticists use pedigrees.

3. Section 1 Human Genetics Vocab • 1. multiple allelesThree or more forms of a gene that code for a single trait.

4. 2. sex-linked geneA gene that is carried on the X or Y chromosome

5. 3. carrierA person who has one recessive allele for a trait and one dominant allele, but does not have the trait.

6. 4. pedigreeA chart or “family tree” that tracks which members of a family have a particular trait.

7. Notes Chromosomes • 1. ____________ exists in pairs.

8. 2. Two traits controlled by many genes are: • A. • B. height skin color

9. 3. Three environmental factors that can effect height are: • A • B • C Lack of protein Lack of minerals Lack of vitamins

10. 23 pairs of • 4. There are __________ chromosomes in each body cell.

11. XY • 5. Males have the ______ combination of chromosomes, while females have the _______ combination XX

12. sperm • 6. The _________ determines the gender of the offspring.

13. Males • 7. ________ are more likely to have a sex-linked trait that is controlled by a ______________ allele. recessive

15. Cells and Heredity Chapter 4 Modern Genetics Section 2 Human Genetic Disorders

16. Section 2 Human Genetic Disorders: Objectives • To describe the causes and symptoms of four human genetic disorders • To explain how genetic disorders are diagnosed.

17. Vocab • 5. genetic disorderAn abnormal condition that a person inherits through genes or chromosomes.

18. 6. amniocentesisA technique by which a small amount of the fluid that surrounds a developing baby is removed; the fluid is analyzed to determine whether the baby will have a genetic disorder.

19. 7. karyotypeA picture of all the chromosomes in a cell arranged in pairs.

20. Notes Genetic Disorders • 1. ______________________ are caused by _____________________, or changes in a person’s ______________. mutations DNA

21. 2. Describe each order and its cause • A. Cystic Fibrosis • Affect- • Cause- Causes think mucus to build up in a person’s lungs and intestines A mutation that is carried on a recessive allele.

22. B. Sickle-Cell • Affect- • Cause- Sickle shaped red blood cells that can not carry as much oxygen as normal blood cells A mutation that affects the production of hemoglobin, a protein in red blood cells that carries oxygen

23. C. Hemophilia • Affect- • Cause- A disorder in which a person’s blood clots very slowly or not at all People with the disorder do not produce one of the proteins needed for normal blood clotting

24. D. Down Syndrome • Affect- • Cause- A distinctive physical appearance, some degree of mental retardation, heart defects. Many people with down syndrome lead full lives. A person’s cells have an extra copy of chromosome 21.

26. Cells and Heredity Chapter 4 Modern Genetics Section 3 Advances in Genetics

27. Section 3 Advances in Genetics: Objectives • To describe three ways in which people have developed organisms with desired traits. • To explain how DNA fingerprinting is used • To state the goal of the Human Genome Project.

28. Vocab • 8. Selective breedingThe process of selecting a few organisms with desired traits to serve as parents of the next generation.

29. 9. InbreedingA selective breeding method in which two individuals with identical or similar sets of alleles are crossed.

30. 10. HybridizationA selective breeding method in which two genetically different individuals are crossed.

31. 11. CloneAn organism that is genetically identical to the organism from which it was produced.

32. 12. Genetic engineeringThe transfer of a gene from the DNA of one organism into another organism, in order to produce an organism with desired traits.

33. 13. Gene therapyThe insertion of working copies of a gene into the cells of a person with a genetic disorder in an attempt to correct the disorder.

34. 14. GenomeAll of the DNA in one cell of an organism.

35. Notes • 1. Two examples of selective breeding • A. • B. Dairy cows are bred to produce larger quantities of milk Varieties of fruits and vegetables that are bred to resist diseases

36. 2. Two examples of inbreeding • A • B Some purebred horses Purebred dogs, such as Labrador retrievers and German sheperds

37. 3. One problem with inbreeding is: Increases the chances of inheriting alleles that lead to genetic disorders.

38. 4. Two examples of hybridization • A. • B. Crossing corn that produces many kernels With corn that is resistant to diseases A mule coming from the cross of a mare and a donkey. The mule has the courage, stamina, and surefootedness of the donkey with the strength of a horse

39. 5. A common example of cloning is *To make a “cutting” from a plant. The cutting can grow into a new plant

40. hair • 6. DNA samples from _______, ______, and _____ can be used to identify a person. skin blood

41. 7. No two people, except _______________ have the same DNA. Identical twins