Lab 12: Genetic Testing

Question 1

Describe the steps of DNA amplification by PCR.

Answer 1

**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.

Question 2

What is taq and why is it used?

Answer 2

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.

Question 3

What is ALU? What does it mean to be +/+, +/- or -/-?

Answer 3

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.

Question 4

Analyze and interpret PCR results for the ALU element given a gel.

Answer 4

(+/+) 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.

Question 5

Explain the process of gel electrophoresis and how it can be used to visualize DNA and determine its size.

Answer 5

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.

Question 6

Define: denaturation, annealing, primer, template, allele, heterozygous, and homozygous.

Answer 6

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.