IB Biology Sub-topic B3.1 Definitions

This page contains our IB Biology definitions for sub-topic B3.1. By learning each one of these definitions, you will fully cover the content for IB Biology 'Gas exchanges'.
alveolus

The smallest component in the lungs where gas exchange occurs

antagonistic muscles

A pair of muscles that exert forces in opposite directions to one another

emphysema

A chronic and progressive disease characterized by a breakdown of alveolar walls leading to larger air sacs with thicker and less permeable walls

epidemiology

The study of incidence and causes of disease

gas exchange

The process of oxygen and carbon dioxide diffusing across the walls of the alveoli

gas exchange

The process by which leaves expel oxygen and obtain carbon dioxide

halophyte

A plant that has adapted itself to a saline environment to conserve water

tidal volume

The volume of air inhaled or exhaled

transpiration

The loss of water as an inevitable consequence of gas exchange

transpiration stream

The flow of water caused by evaporation at the leaf putting tension on the column of water

ventilation

The consistent removal and replacement of air in the lungs via inhalation and exhalation of air

ventilation rate

The number of inhalations or exhalations per minute

xerophyte

A plant that has adapted itself to a desert environment to conserve water

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