Amino acid
Any of a class of 20 molecules that are combined to form proteins in living things. The sequence of amino acids in a protein, and hence protein function.

Angiogenesis
Blood vessel formation, which usually accompanies the growth of malignant tissue.

Antibiotics
Drugs used to treat infection.

Antibody
A protein produced by certain white blood cells in response to a foreign substance (antigen). Each antibody can bind only to a specific antigen.

Antigen
Any foreign or "non-self" substance that, when introduced into the body, causes the immune system to create an antibody.

Apoptosis
A normal cellular process involving a genetically programmed series of events leading to the death of a cell.

B cells
White blood cells that develop in the bone marrow and are the source of antibodies. Also known as B lymphocytes.

Benign
Not cancerous; does not invade nearby tissue or spread to other parts of the body.

Biotechnology
A set of biological techniques developed through basic research and now applied to research and product development.

Cancer
Diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissue and can spread through the bloodstream and lymphatic system.

Cell
Small, watery, membrane-bound compartment filled with chemicals; the basic unit of any living thing.

Chromosomes
Structures found in the nucleus of a cell, which contain the genes. Chromosomes come in pairs, and a normal human cell contains 46 chromosomes, 22 pairs  

Clinical trials
Research studies that involve patients. Each study is designed to find better ways to prevent, detect, diagnose, or treat disease.

Clone
A group of identical genes, cells, or organisms derived from a single ancestor.

Differentiation
In cancer, refers to how mature (developed) the cancer cells are in a tumour. Differentiated tumour cells resemble normal cells and grow at a slower rate than undifferentiated tumour.

DNA
The substance of heredity; a linear molecule that carries the genetic information that cells need to replicate and to produce proteins and DNA.

Drug
Any chemical compound that may be used on humans to help in diagnosis, treatment, cure, mitigation, or prevention of disease or other abnormal conditions.

E. coli
Common bacterium that has been studied intensively by geneticists because of its small genome size, normal lack of pathogenicity, and ease of growth in the laboratory.

Enzyme
A protein that acts as a catalyst, affecting the rate at which chemical reactions occur in cells.

Etiology
The study of the causes of abnormal condition or disease.

False negative
When a test wrongly shows an effect or condition to be absent (e.g., that a woman is not pregnant when, in fact, she is).

False positive
When a test wrongly shows an effect or condition to be present (e.g. that is woman is pregnant when, in fact, she is not).

Gamete
Mature male or female reproductive cell (sperm or ovum) with a haploid set of chromosomes (23 for humans).

Gene
A unit of inheritance; a working subunit of DNA.  Each of the body's 50,000 to 100,000 genes contains the code for a specific product, typically, a protein such as an gene's coded information is translated into the structures present and operating in the cell (either proteins or RNAs).

Gene therapy
Treatment that alters genes - the basic units of heredity found in all cells in the body.

Genetic code
The sequence of nucleotides, coded in triplets (codons) along the mRNA, that determines the sequence of amino acids in protein synthesis.

Genetics
The scientific study of heredity how particular qualities or traits are transmitted from parents to offspring.

Genome
All the genetic material in the chromosomes of a particular organism; its size is generally given as its total number of base pairs.

Genotype
Genetic constitution of an organism.

Hormones
Chemicals produced by glands in the body and circulate in the bloodstream. Hormones control the actions of certain cells or organs.

Immune system
The complex group of cells and organs that defends the body against infection and disease.

In vitro
Outside a living organism.

In vivo
Latin phrase meaning "in life"; in the living organism as opposed to in vitro.

Informatics
The study of the application of computer and statistical techniques to the management of information.

Lymphatic system
The tissues and organs, including the bone marrow, spleen, thymus, and lymph nodes, that produce and store cells that fight infection..

Medical device
A diagnostic or therapeutic article that does not work by chemical action.

Metastasis
The spread of cancer from one part of the body to another. Cells in the metastatic (secondary) tumour are like those in the original (primary) tumour.

Mitosis
The process of nuclear division in cells that produces daughter cells that are genetically identical to each other and to the parent cell.

Mutation
A change in the number, arrangement, or molecular sequence of a gene.

Nucleic acid
A large molecule composed of nucleotide subunits.

Nucleotide
A molecule consisting of a nucleoside with one or more phosphate groups.

Oncogene
A unit of DNA that normally directs cell growth, but which can also promote or allow the uncontrolled growth of cancer if damaged (mutated) by an environmental exposure to carcinogens

Organelle
A discrete subcellular structure that has a specialised function (eg, nucleus, mitochondrion).

Peptide
A molecule consisting of 2 to approximately 20 amino acids connected by peptide bonds; a short segment of a larger protein or a completely functional molecule unto itself.

pH
"Potency of hydrogen"; a measure of acidity or alkalinity.

Phenotype
Observable characteristics of an organism produced by the organism's genotype interacting with the environment.

Plasmid
Autonomously replicating, extrachromosomal circular DNA molecules, distinct from the normal bacterial genome and nonessential for cell survival.

Protein
A large, complex molecule composed of amino acids.

Receptor
A protein or group of associated proteins in a cell or on its surface that selectively binds a specific substance (called a ligand).

Recessive
A gene that is phenotypically manifest in the homozygous state but is masked in the heterozygote by the presence of a dominant allele.

Recombination
The natural process of breaking and rejoining DNA strands to produce new combinations of genes and, thus, generate genetic variation.

Red blood cells
Cells that carry oxygen to all parts of the body. Also called erythrocytes.

RNA
A chemical found in the nucleus and cytoplasm of cells; it plays an important role in protein synthesis and other chemical activities of the cells from which all blood cells develop.

T cell
White blood cell critical to the immune response.

Telomere
The ends of chromosomes. These specialized structures are involved in the replication and stability of linear DNA molecules. See DNA replication.

Transcription
The process of copying information from DNA into new strands of messenger RNA (mRNA).

Transfer RNA
A class of RNA having structures with triplet nucleotide sequences that are complementary to the triplet nucleotide coding sequences of mRNA.

Translation
The process of turning instructions from mRNA, base by base, into chains of amino acids that then fold into proteins.

Tumor necrosis factor
A type of biological response modifier (a substance that can improve the body's natural response to disease).

Tumor suppressor gene
Genes that normally restrain cell growth but, when missing or inactivated by mutation, allow cells to grow uncontrolled.

Vector
A self-replicating DNA molecule that transfers a DNA segment between host cells.