Unit 4 Biology Mendelian Genetics Guiding Questions 1. What did Gregor Mendel work with to study the inheritance of traits? 2. 3. 4. 5. 6. What is the Theory of Particulate Inheritance? What is the Law of Segregation What is the Law of Independent Assortment? What is meant by genotype? What is meant by phenotype? 7. What is a homozygote? 8. What is a heterozygote? 9. What is meant by the term hemizygous? 10. 11. 12. 13. 14. Does dominant relate to phenotype or genes? What types of phenotypes can there be? What is a dominant phenotype? What is a recessive phenotype? Is a dominant allele always the most common? 15. Are homozygous and heterozygous individuals easily distinguished in complete dominance? 16. What is the alternative phenotype in complete dominance? 17. In incomplete dominance does the heterozygote have the same phenotype as either homozygote? 18. Why are pink snap dragon flowers produced? 19. 20. 21. 22. What happens to phenotypes in codominance? What is an example of codominant phenotypes? What is the relationship between phenotype produced by A allele and B allele? Is the phenotype for the O allele codominant? 23. 24. 25. 26. 27. 28. What do we mean by multiple genes at a single locus? Do dominance relationships remain stable? Can genes affect more than one phenotype? What type of gene affect more than one phenotype? What is an example of a gene that affects more than one phenotype? What is meant by a recessive lethal mutation? 29. What are some examples of the influence of environment on phenotype? 30. What is a monohybrid cross? 31. What is the F1 generation? 32. What is the F2 generation? 33. When do we achieve a 3:1 phenotypic ratio in the F2 generation of a monohybrid cross? 34. When do we achieve a 1:2:1 phenotypic ratio in the F2 generation of a monohybrid cross? 35. What is a dihybrid cross? 36. What criteria needs to be met in order to achieve a 9:3:3:1 phenotypic ratio in a dihybrid cross? 37. What is a back cross? 38. What is a test cross? 39. Why is a test cross carried out? 40. What do the phenotypic ratios achieved in F2 generation and test cross offspring tell us? 41. 42. 43. 44. What is linkage? Is linkage complete? What can linkage and the phenomenon of crossing over allow us to do? How do we denote linked genes? 45. When crossing two F1 heterozygotes for a pair of linked genes what sort of ratio do we expect if we ignore crossing over? 46. How do genes assort if they are not linked? 47. What happens to the phenotypic ratio when genes are linked? 48. When are genes considered to be linked? 49. How do we estimate the distance between linked genes? 50. Can phenotypes be influenced by more than one gene?