Deoxyribonucleic Acid (DNA)

The molecule of heredity, common to all life forms, that is passed from parents to offspring.

Chromosome

A single, large DNA molecule wrapped around proteins. Chromosomes are located in the nulei of most eukaryotic cells. 

Nucleotides

The building blocks of DNA. Each nucleotide consists of a sugar, a phosphate, and a base. The sequence of nucleotides (A s, C s, G s, T s) along a DNA strand is unique to each person. 

Double Helix

The spiral structure formed by two strands of DNA nucleotides bound together. 

DNA Profile

A visual representation of a person's unique DNA sequence. 

Polymerase Chain Reaction (PCR)

A lavoratory technique used to replicate, and thus amplify, a specific DNA segment. 

DNA Replication

The natural process by which cells make an idential copy of DNA molecule. 

Complementary 

Two strands of DNA are said to be complementary in that A always pairs with T, and G always pairs with C. 

DNA Polymerase

An enzyme that "reads" the sequence of a DNA strand and helps to add complementary nucleotides to form a new strand during DNA replication. 

Semi-Conservative

DNA replication is said to be semi-conservative because each newly made DNA molecule has one original and one new strand of DNA.

Genome

One complete set of genetic instructions encoded in the DNA of an organism.

Short Tandem Repeats (STRs)

Sections of a chromosome in which DNA sequences are repeated. 

Coding Regions

Sequences of DNA that serve as instructions for making proteins. 

Noncoding Regions

DNA sequences that do not hold instructions to make proteins. 

Gel Electrophoresis

A lavoratory technique that separates fragments of DNA by size