unit 2 - ka5: metabolism and adverse conditions

• Many environments vary beyond the tolerable limits for normal metabolic activity for any particular organism. Some animals have adapted to survive these adverse conditions while others avoid them
• Surviving adverse conditions by dormancy.
• Dormancy is part of some organisms’ life cycle to allow survival during a period when the costs of continued normal metabolic activity would be too high. The metabolic rate can be reduced during dormancy to save energy.
• During dormancy there is a decrease in metabolic rate, heart rate, breathing rate and body temperature.
• Dormancy can be predictive or consequential.
• Predictive dormancy occurs before the onset of adverse conditions.
• Consequential dormancy occurs after the onset of adverse conditions.
• Some mammals survive during winter/low temperatures by hibernating. Aestivation allows survival in periods of high temperature or drought. Daily torpor is a period of reduced activity in some animals with high metabolic rates.
• Avoiding adverse conditions by migration.
• Migration avoids metabolic adversity by expending energy to relocate to a more suitable environment.
• Migratory behaviour can be innate and learned.
• Specialised techniques are used to study long-distance migration.
• Examples of specialist techniques are satellite tracking and leg rings