Lab 12: Genetic Testing Flashcards
Describe the steps of DNA amplification by PCR.
**DNA Amplification by PCR Steps:
1. Denaturation: Process by which DNA strands are sperated caused by the rxn mixture heating up where many enzymes are destroyed except Taq polymerase.
2.Annealing: Process by which oligonucleotide primers attach to their complemetary DNA strand to begin the replication process.
**3. Extension: **Taq polymerase now binds the nucleotides together creating a complementary sequence.
These steps repeat about 35-40 times called the PCR-cyle for a complete PCR amplification.
What is taq and why is it used?
Taq polymerase is a catalyst that synthesizes new DNA ny the attachment of nucleotides.
Its used because its capable of surviving high temperatures and does nto die.
What is ALU? What does it mean to be +/+, +/- or -/-?
ALU is a DNA sequence with about 300 base pairs and replicaties about 500,00 times in the human genome.
+/+ means you are Homozygous: Indicated the ALU is present in both strands.
-/- Homozygous: Indicates neither of the ALU is present.
-/+ Hterozygous: Indicates that there is one ALU present and the other does not contain it.
Analyze and interpret PCR results for the ALU element given a gel.
(+/+) Homozygous: Both ALU inserts, in the gel will move at the same speed with one band corresponsing to the 941 base pairs.
(-/-) Homozygous: Neither ALU inserts, migrate as one band that corresponds to 641 base pairs.
(+/-) Heterozygous: One with ALU insert nd the next with no ALU insert, their willl be two band present, one for 941 and one 641.
Explain the process of gel electrophoresis and how it can be used to visualize DNA and determine its size.
The gel electrophoresis process involves an agarose gel where the DNA sample mixture is placed. A buffer tsolution is added below the gell. Then its charged and the netaive charged DNA fragements are moved to the positive chargeddirection.
We then use a uv light to visualice the DNA fragements anf we can now determine its size.
Define: denaturation, annealing, primer, template, allele, heterozygous, and homozygous.
Denaturation: to denature or destroy by heat, in this case DNA strand is seperated.
Annealing: To allow DNA primers to attach to to the template.
Primer: a small DNA sequence used to begind DNA replication.
Template: The template strand where the new DNA can attach to.
Allele: a version of a gene.
Heterozygous: Containg a recessive and dominant allele.
Homozygous: Containg either dominant or recessve alleles.