Phylum Physiology Study of the processes occurring in living organisms. Pigment Substance that absorbs light, often selectively. The production by a single gene of more than one effect on the phenotype . Plesiomorphic Plumule Terminal bud of a plant embryo, usually consisting of embryonic leaves and the epicotyl . Pneumocystis carinii Poikilothermic Having a body temperature that fluctuates with that of the surroundings.
Some polyps tend in time to develop a malignant clone of cells.
All the members of a single species present in a defined area. PPM Parts per million. Precursor activation Predation Living by devouring other organisms. Primary transcript Primitive Similar to that occurring in the early evolutionary history of the structure or organism in question. Producers start food chains .