Jumping Genes
These DNA sequences are nicknamed “jumping genes” because they can move or copy themselves within a genome.
What are transposons?
These two sample types can provide cells for DNA extraction in the activity.
What are cheek cells and hair follicles?
This PCR component contains the PV92 DNA region to be copied.
What is template DNA?
This fragment length indicates the PV92 insertion is present.
What is 941 bp?
Each student with a valid genotype contributes this many PV92 alleles.
What are two alleles?
This class of transposons uses an RNA intermediate and commonly leaves the original copy in place.
What are Class I retrotransposons?
This extraction material binds magnesium ions, helping protect DNA from DNases.
What is InstaGene matrix?
These short DNA sequences flank the target and indicate where copying begins.
What are primers?
This fragment length indicates the PV92 insertion is absent.
What is 641 bp?
In 8 +/+, 10 +/−, and 6 −/− students, this is the total number of alleles.
What is 48? Calculation: 24 students × 2 = 48.
This class of transposons moves as DNA in a cut-and-paste process.
What are Class II DNA transposons?
Magnesium ions have this charge property because they carry two positive charges.
What does divalent mean?
During this PCR step, heat separates the two DNA strands.
What is denaturation?
This genotype has both a 941 bp band and a 641 bp band.
What is +/−, or heterozygous?
In 8 +/+, 10 +/−, and 6 −/− students, this is the number of insertion (+) alleles.
What is 26? Calculation: (2 × 8) + 10 = 26.
Alu elements are found in these organisms and are no longer mobile in the PV92 activity.
What are primates?
These enzymes can degrade DNA and may require free magnesium as a cofactor.
What are DNases?
During this step, primers bind to matching sequences on the template DNA.
What is annealing?
On an agarose gel, fragments of this relative size generally travel farther.
What are smaller fragments?
For 8 +/+, 10 +/−, and 6 −/− students, this is the approximate insertion allele frequency.
What is 0.54, or 54%? Calculation: 26 ÷ 48 ≈ 0.54.
The PV92 Alu insertion adds about this many base pairs to the amplified region.
What is about 300 base pairs?
PCR polymerase needs this ion available in the reaction, even though InstaGene binds magnesium during extraction.
What is free Mg²⁺?
During this step, DNA polymerase adds nucleotides to build new DNA strands.
What is extension?
A sample lane with no amplified product has this status and should be excluded from allele-frequency calculations.
What is an undetermined genotype?
Among 15 students, 4 are +/+, 6 are +/−, and 5 are −/−. This is the insertion allele frequency.
What is about 0.467, or 46.7%? Calculation: ((2 × 4) + 6) ÷ (15 × 2) = 14 ÷ 30 ≈ 0.467.