• Abiotic Factor:  non-living factor in an eco-system

    Acid:  a compound that forms hydrogen ions (H+) in solution (0-7pH)

    Acid Rain:  rain containing nitric and sulfuric acids which destroys living and non-living factors in an ecosystem

    Active Immunity:  immunity produced by a vaccine or actual exposure to an illness

    Active Transport:  energy-requiring process that moves materials across a cell membrane from low concentration to high (agains the concentration gradient) using ATP

    Adaptation:  inherited characterisitcs which increase an organism's chance of survival

    Adenosine Tri-phosphate (ATP): m