The long term frequency of an event relative to all alternative events, and usually expressed as decimal fraction. Proband Individual in a family who brought the family to medical attention. Probe Single-stranded DNA labeled with radioactive isotopes or tagged in other ways for ease in identification. A female hormone. Prokaryote Cell or organism lacking a membrane- bound, structurally discrete nucleus and other subcellular compartments.
Bacteria are prokaryotes.
Promoter A site on DNA to which RNA polymerase will bind and initiate transcription. Proofreader genes See DNA repair genes. Prophylactic surgery Surgery to remove tissue that is in danger of becoming cancerous, before cancer has the chance to develop. Surgery to remove the breasts of women at high risk of developing breast cancer is known as prophylactic mastectomy. A large, complex molecule composed of amino acids.