Exp 2 Quizzes Flashcards
(62 cards)
STR locations that are amplified for the CODIS system (combined DNA index system) are found on different chromosomes for each unique STR.
true
Which of the following is true regarding Multiplex PCR?
more than one primer set is used in the same reaction
more than DNA locus (location) is targeted for amplificaiton.
A single set of primers within the reaction can amplify multiple regions of the genome
there can be two different PCR products for each STR location in the genome if the parent is heterozygous
More than one primer, More than one Gene locus, two different PCR products for each STR location
Which of the following is true regarding capillary electrophoresis?
it is better at separating DNA than agarose gel electrophoresis
it uses the fluorescence on the primers that integrate into PCR products to detect the DNA
it separates DNA based on size where larger DNA travels faster in the capillary than smaller sized fragment
it is better at separating DNA than agarose gel electrophoresis
it uses the fluorescence on the primers that integrate into PCR products to detect the DNA
Identical twins will have the same exact STR profile when their electropherograms are analyzed.
true or false
false
When performing the genotype exclusion analysis, the obligate paternal allele is the STR repeat allele that the mother did not give to the child.
Group of answer choices
true
The paternity index for any one STR locus is calculated based on the Hardy Weinberg equation to account for homozygote and heterozygote frequencies.
false
The Combined Paternity Index is calculated simply by taking the product of all individual PI’s (Paternity Indices) at all loci tested.
true
Identity matching that is used for Crime Scene Investigations (CSI) is based on examining whether the suspect’s alleles at ALL STR loci match the individual in question.
Group of answer choices
true
What are the steps to this experiment
1.) extract genomic DNA
2.) Determine DNA concentration
3.) Set up multiplexed PCR
4.) Separate PCR products with capillary electrophoresis
5.) Analyze PCR
What is the purpose of PCR
to make billions of copies of a specific DNA sequence of interest
Does PCR eliminate the rest of the DNA when it amplifies the specific target sequence?
n, but it makes so many copies of the specific sequence that there is only a minimal amount of interference from the rest of the DNA
What biological process does PCR imitate
it imitates DNA replication but only amplifies short highly specific stretches of DNA
What are the 4 steps to PCR
1) Denaturation 2) primer annealing 3) primer extension 4) cycling
What defines the sequences of DNA that are amplified
the primers used in the reaction
What is the purpose of the denaturing step
When we denature, we are separating the double-stranded DNA and exposing the single-stranded regions to the DNA polymerase
In PCR, how do we denature the DNA
we use heat
What temperature is the denaturing step of PCR
92-94 °C
What is the purpose of annealing the primers
the primers need to find their single-stranded complementary sequences and hybridize
what do the primers do?
the primers specify which region the polymerase needs to amplify and provides a 3’OH
At what temperature do primers have the greatest specificity?
at the melting temperature
What occurs at the melting temperature
the primers just barely “sit down” on its complementary sequence without melting off
What types of primers have lower melting temperatures?
AT rich primers are less stable and tend to melt off more easily than GC rich primers so they have lower melting temperatures
When assigning melting temperatures, how many degrees do we assign for each A/T? what about G/C?
For each A/T we add 2
For each G/C, we add 4
What occurs during the primer extension step
DNA polymerases recognize the 3’ end of the polymerases ad begins extending the primers TOWARDS each other across the target sequence
