bio - /ˈbīō/

• Etymology: From Ancient Greek βίο- (bío-), combining form and stem of βίος (bíos, “life”).
• Prefix: bio-
  • life
  • biological

theta - /ˈTHādə,ˈTHēdə/

• Etymology: From Ancient Greek θῆτα (thêta).
• Noun: theta (plural thetas)
  • The eighth letter of the Modern Greek alphabet, ninth in Old Greek: Θ,θ
  • (statistics) Used to denote the unknown parameter or variable.