Biology Dictionary
B
Bioaccumulation: The accumulation of persistent pesticide in the tissues of organisms in a food chain
Biochemical oxygen demand (BOD): The amount of oxygen used by aerobic micro-organisms as they break down organic materials in water.
Biodiversity: The range of species present in a habitat.
Biological pest control: The use of predators or parasites to control the population of a pest species.
Biotic: Any living or biological factor.
Bohr Effect (Shift): the presence of CO2. (more accurately - the H+ ions resulting from the presence of CO2) lowers haemoglobin’s affinity for O2 and so the dissociation curve shifts to the right. The significance is that oxygen is released to the respiring tissues that need it.
Bundle of His: Specialised cardiac muscle fibres which are found in the ventricular septum (muscle wall between ventricles). Receives impulses from the AVN and transfers it to the Purkyne fibres.