Exam 3 Study Guide 2

Three-point testcross

A genetic cross used to determine the order and distance between three genes on a chromosome.

Map distance

Calculated using the formula RF = # of recombinant progeny/total # of progeny x 100.

Somatic cell hybridization

A technique used to determine a human gene's location on chromosomes by creating hybrid human/mice cells.

Karyotype

A visual representation of chromosomes used to identify chromosomal variants by analyzing size, shape, and banding.

Chromosomal rearrangements

Structural alterations of chromosomes involving duplications, deletions, inversions, and translocations.

Aneuploidies

Conditions involving extra or missing chromosomes.

Polyploidies

Conditions involving an extra set of haploid chromosomes.

Recombinant DNA

DNA that has been artificially made by combining DNA from different sources using restriction enzymes.

Gel electrophoresis

A laboratory technique for separating DNA fragments based on their size using an electric field.

Polymerase Chain Reaction (PCR)

A method used to amplify DNA by repeated cycles of denaturation, annealing, and elongation.

Dideoxy sequencing

A method of DNA sequencing that uses dideoxynucleotides to terminate DNA strand elongation.

Conjugation

A mechanism of bacterial gene transfer that involves direct cell contact and the formation of a sex pilus.

Lytic cycle

A life cycle of bacteriophages where the host cell is infected, and new phages are produced, leading to cell lysis.

Semiconservative replication

The mechanism of DNA replication where each new DNA molecule consists of one old strand and one new strand.

Exonuclease activity

The capability of DNA polymerases to remove nucleotides from the ends of DNA strands.

End replication problem

The issue of incomplete replication at chromosome ends, mitigated by telomerase adding repetitive sequences.

Transcription

The process of synthesizing RNA from a DNA template.

Rho-dependent termination

A mechanism in bacteria that requires the rho factor to terminate transcription.

Rho-independent termination

A mechanism in bacteria where a hairpin loop in RNA halts transcription.