exam 3 Flashcards
What can we assume about the ros and anL genes?
That they are on different chromosomes
What is the phenotypic outcome of the F2 group resulting from a F1 (ROS/ros; ANL/anL) self cross?
9/16- 56.25% tall and purple
3/16- 18.75% tall and green
3/16- 18.75% short and purple
1/16- 6.25% short and green
What is Sanger sequencing?
Using DNA polymerase to obtain a relatively short copy
What type of termination is used in Sanger sequencing?
Di-deoxychain termination
How are ddNTPs modified?
With fluorescent tags that emit and label/identity at the end of each fragment
What is added to a Sanger sequencing reaction?
DNA template, primer, DNA polymerase, dNTPs, and ddNTPs
How many primers are added to Sanger sequencing?
One
Why cant you add dNTPs to ddNTPs?
ddNTPs do not have an oxygen on 2’ or 3’ carbon. 3’OH is required to add bases
What is the result of Sanger sequencing?
A large amount of fragments of differencing sizes that only vary due to one base pair
What strand is labeled in Sanger sequencing? Synthesized or template?
Synthesized has the labeled terminal nucleotides and it is complementary to the template
Can you see the nucleotide bases on agarose gel?
No
How is the sequencing chromatogram obtained?
Laser is sent through strands and through a detector
What are the five requirements that tell you that you have a good chromatogram sequence?
- Individual, well defined peaks
- No overlapping peaks unless heterozygosity is expected
- No N bases in the middle of the sequence
- High signal to noise ratio
- 700-1000bp or the length you expect
What does the primer provide for DNA polymerase in the sequencing reaction?
3’ OH group
What is mendels second law?
Principle of independent assortment- gene pairs on different chromosomes pairs assort independently at meiosis
How do you obtain a phenotypic 9:3:3:1 ratio?
F1 self cross
What is the genotype and phenotype of the F1 plants we made in class? What gametes (4) do they produce?
Genotype- ROS/ros; ANL/anL
Phenotype- tall x purple
ROS;ANL
ros;anL
ros;ANL
ROS;anL
What phenotypic ratios do we expect in the F2 progeny?
Tall green R_;aa 3/16 18.75%
Short purple rr;A_ 3/16 18.75%
Tall purple R_;A_ 9/16 56.25%
Short green rr;aa 1/16 6.25%
What is the null and alternative hypothesis for Mendelian segregation chi squared?
Ho: The numbers of plants we observe in the phenotypic classes are consistent with Mendelian segregation
Ha: The number of plants we observe in the phenotypic classes are not consistent with Mendelian segregation, another form of inheritance
What is the purpose of the chi square test?
To compare the observed frequencies of phenotypes vs the expected. Allows us to accept or reject the null hypothesis based on likelihood ratio