Genetic Polymorphism & Identity Vocabulary Study Guide

Vocabulary flashcards generated from the Genetic Polymorphism & Identity study guide covering key terms, laboratory techniques, definitions, and underlying molecular mechanisms.

Coding Regions

Genes within the human genome that code for proteins.

Non-Coding Regions

Regions of the human genome containing highly variable, short repetitive sequences of DNA that differ drastically between individuals.

Restriction Enzyme

Enzymes of bacterial origin that recognize a highly specific sequence of nucleotides (restriction site) and precisely cut both strands of the DNA molecule at that specific site.

Restriction Site

A highly specific sequence of nucleotides recognized and cut by a restriction enzyme.

Mathematical Cleavage Rule

In a linear double-stranded DNA molecule, if there are $N$ recognition sites for a specific restriction enzyme, the enzyme will cut the molecule into exactly $N + 1$ fragments.

RFLP

Restriction Fragment Length Polymorphism; variation in the length of restriction fragments between normal and mutant alleles caused by mutations modifying restriction site locations, serving as a molecular fingerprint.

FISH

Fluorescent In Situ Hybridization; a methodology using single-locus fluorescent probes and complementary base pairing to locate a specific gene or locus on a physical chromosome.

DNA Fingerprint

A unique pattern of dark bands on an autoradiogram film created using the Jeffreys multi-locus probe technique to establish an individual's unique genetic identity.

Ethidium Bromide

A stain used during gel electrophoresis to visualize distinct DNA fragments as bands under ultraviolet (UV) light exposure.

Southern Blotting

The laboratory process of transferring separated DNA fragments from a gel matrix and fixing them onto a solid membrane (filter paper).

Denaturation

The step in FISH where heating breaks weak hydrogen bonds to separate double-stranded chromosomal DNA into single strands, exposing the target nucleotide sequence.

Hybridization

The step in FISH where cooling allows hydrogen bonds to re-form, permitting a single-locus fluorescent probe to bind specifically to its complementary target sequence on the chromosome.

The Migration Principle

The principle stating that net negatively charged DNA molecules migrate from the negative electrode (cathode) toward the positive electrode (anode), with smaller DNA fragments moving faster and farther through gel pores than larger fragments.

Monozygotic Twins

Identical twins originating from a single fertilized egg (zygote) that splits into two embryos; they represent the only exception where two individuals share an absolutely identical DNA fingerprint.

Single-Locus Probe

A known single-locus fluorescent probe used in FISH to bind via complementary base pairing and mark a specific locus on a chromosome.

Multi-Locus Probe

A radioactive, labeled DNA probe used in the Jeffreys DNA fingerprinting technique that hybridizes to denatured membrane fragments.

Genetic Map

A structural map or diagram showing the relative physical locations of structural loci or genes along a chromosome.

EcoRI

A specific restriction enzyme used in restriction digestion mechanics that recognizes and cuts specific DNA sequences.