WordNet (r) 3.0 (2006):

life science
    n 1: any of the branches of natural science dealing with the
         structure and behavior of living organisms [syn: life
         science, bioscience]

Moby Thesaurus II by Grady Ward, 1.0:

38 Moby Thesaurus words for "life science":
   aerobiology, agrobiology, anatomy, astrobiology, bacteriology,
   biochemics, biochemistry, biochemy, bioecology, biological science,
   biology, biometrics, biometry, bionics, bionomics, biophysics,
   botany, cell physiology, cryobiology, cybernetics, cytology,
   ecology, electrobiology, embryology, enzymology, ethnobiology,
   exobiology, genetics, gnotobiotics, microbiology,
   molecular biology, pharmacology, physiology, radiobiology,
   taxonomy, virology, xenobiology, zoology