The terms and descriptions provided in this glossary have been completed with the help of several sources:

• National Human Genome Research Institute - Talking Glossary
• Human Genome Project Information
• PhRMA Genomics (no longer online)
• Word Central's Student Dictionary (Merriam Webster)

Sources are listed with the definitions.

STU

Sequencing

To determine the order of letters or nucelotides in a DNA or protein molecule.

Sex chromosome

A sex chromosome is one of the two chromosomes that specify an organism's genetic sex. Humans have two kinds of sex chromosomes, one called X and the other Y. Normal females possess two X-chromosomes and normal males one X and one Y. [Talking Glossary]

Species

A single, distinct class of living creature with features that distinguish it from others.

Stem cell

The most primitive type of cell in the body, being undifferentiated and having full potential to keep dividing throughout life and give rise to specialized cells.
Source: www.arthritisnsw.org.au/research/glossary.html

Thymine

One of the four bases in DNA that make up the letters ATCG, thymine is the "T". The others are adenine, cytosine, and guanine. Thymine always pairs with adenine. [Talking Glossary]

Traits

Ways of looking, thinking, or being. Genetic traits are passed down through the genes from parents to offspring.
Source: Human Genome Project Information

Transcription

The process during which the information in a length of DNA is used to construct an mRNA molecule.
Source: PhRMA Genomics

Transfer RNA (tRNA)

RNA molecules which bond with amino acids and transfer them to ribosomes, where protein synthesis is completed.
Source: PhRMA Genomics

Transgenic

An experimentally produced organism in which DNA has been artificially introduced and incorporated into the organism's germ line, usually by injecting the foreign DNA into the nucleus of a fertilized embryo. [Talking Glossary]

Translation

The process during which the information in mRNA molecules is used to construct proteins.
Source: PhRMA Genomics

Ultrasound imaging

A technique for looking inside the body by using sound waves to create images.
Source: Human Genome Project Information

Uracil

Uracil is one of the four bases in RNA. The others are adenine, cytosine, and guanine. Uracil replaces thymine, which is the fourth base in DNA. Like thymine, uracil always pairs with adenine. [Talking Glossary]