Quantitative Traits
Quantitative Traits Distribution of Corn Ear Lengths
Mendelian Explanation of a Quantitative Trait Very small : Small : Medium : Large : Very Large
Study Question 3 How many discrete lengths would you predict to be possible if there were four identical Height genes?
Complementation Multiple Infection Multiplicity of Infection Phage/Hosts
Complementation Failure to Complement
Complementation
Study Question 4 5 mutants of phage T2 Mutants forms tiny plaques Complementation tests - coinfect E. coli with pairs How many genes are required for the wildtype phenotype?
Study Question 5-7 Cross female #34 extra hairy x male #43 (Curly hair) Possible genotypes of parents? Genotypes of F 1 progeny? #34: EE x #43: CC EC One gene hypothesis #34: EE ++ x #43: ++ CC E+ C+ Two gene hypothesis #34: X E X E ++ x #43: X + Y CC Two gene hypothesis/one X-linked X + X E C+ X E Y C+
Recombination Nicked strand invades other chromosomeOne strand nickedHomologous chromosomes pairOther strands breakRecombination complete
Recombination No change (sequences are identical except for sites of mutation)
Recombination Two novel DNA’s, different from parents
Complementation vs Recombination Complementation Recombination acts through protein acts through DNA temporary permanent efficient rare useful to define genes useful to map genes