Lecture 17: DNA Discovery and Replication Flashcards
How can something be purified?
- Separate a mixture into its components
- Assay each component to see which has the desired property
What is an assay?
-A way of measuring something
-Can measure a substance
-Or can measure a phenomenon such as memory
Cis chromosome?
-Chromosome contains both dominant or both recessive alleles
Trans chromosome?
-Chromosome contains one dominant and one recessive allele
Semi-dominant trait?
Blending of two alleles that results in a third phenotype that is different from the parents(heterozygous is different)
ex. RR(white), rr(red), Rr(pink)
Alleric Series
-More than two alleles per gene(R, r, r’)
Multigenic/Polygenic
Multiple genes affect one phenotype
Penetrance
Percentage of individuals of a given genotype that actually show the phenotype
Expressivity
Degree to which a phenotype is expressed(mild symptoms vs severe)
What three factors contribute to the continuous spectrum?
- Alleric Series
- Multigenic
- Environmental effects(penetrance/exppresivity)
How can DNA be purified?
- Grind up fav organism
- Extract the lipids and proteins of the organism with solvent
- Precipitate with ethanol
How was it determined that genetic material was actually genetic material?
It was thought that if you dip another organism in another organisms DNA that the organism should come out as the other organism
For what organisms does dipping into DNA work?
- Viruses
- Bacteria
What was Frederick Griffiths Experiment?
- Injected S Strain bacteria into mice they would die.
- Injected R strain bacteria into mice, they would live
- Heated up the S strain bacteria and killed it and when he injected it into the mice they survived
- Mixed dead S strain bacteria with living R strain bacteria the mice died
What did Federico Griffith’s experiment prove?
-A chemical component of one cell is capable of genetically transforming another cell
- R strain bacteria inherited the S strains DNA
How do phage infect bacteria?
-Phage bind to bacteria and inject them with their DNA
-The bacteria then replicates this DNA , producing phages that burst out of the bacteria and infect others