XXXXXXXXXXXX: XXX study XX XXX XXXXXXXX XXXXXXXXXX that make up XXXXXX thingsXXXXXX: the XXXXX of plants, XXXXXXXXX agricultureCellular biology: XXX XXXXX XX XXX XXXXX cellular XXXXX of living XXXXXXXXXXXXX: the XXXXX of how organisms interact XXXX XXXXX environmentEvolutionary biology: XXX XXXXX of the XXXXXXX and XXXXXXX in XXX XXXXXXXXX XX XXXX XXXX timeXXXXXXXX: XXX XXXXX XX heredityMolecular XXXXXXX: the XXXXX of biological moleculesXXXXXXXXXX: XXX study of the functions XX organisms XXX their partsZoology: the XXXXX XX XXXXXXX, including animal behaviorAdding XX the XXXXXXXXXX of XXXX XXXXXXXX idea XX the XXXX XXXX these fields XXXXXXX. XX is XXXXXXXXXX XX XXXXX zoology without knowing a great XXXX XXXXX XXXXXXXXX, physiology XXX ecology. XXX can't study XXXXXXXX XXXXXXX XXXXXXX knowing biochemistry and molecular XXXXXXX XX well.