| what happens when environments vary beyond the tolerable limits for normal metabolic activity for any particular organism | some animals have adapted to survive the adverse conditions while others avoid them |
| what is meant by adverse conditions | extreme temperatures or lack of water |
| what is dormancy | it 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 |
| how can energy be saved during dormancy | metabolic rate can be reduced |
| what happens to metabolic rate, heart rate, breathing rate and temperature during dormancy | heart rate, metabolic rate, breathing rate and body temperature decrease |
| name three types of dormancy | hibernation
aestivation
daily torpor |
| describe hibernation | some mammals survive during winter/low temperatures by hibernating
heart rate, breathing rate, body temperature and levels of activity decrease so the minimum amount of energy is expended to maintain vital cell ativity |
| describe aestivation | allows survival in periods of high temperature or drought |
| describe daily torpor | this is a period of reduced activity in some mammals with high metabolic rates |
| what are the two things dormancy can be? | predictive
consequential |
| describe predictive dormancy | occurs before the onset of adverse conditions
common in environments which have predictable seasons where the temperature and photoperiod (numbers of hours of daylight) can be used as triggers |
| describe consequential dormancy | occurs after the onset of adverse conditions
common among organisms living in unpredictable environments. |
| what is an advantage of consequential dormancy | organism may remain active for longer and continue to make use of the available resources. |
| what is a disadvantage of consequential dormancy | organisms run the risk of being killed off in the event of a sudden and severe environmental change |
| what is migration | when organisms avoid metabolic adversity by expending energy to relocate to a more suitable environment |
| how can long distance migration be studied | using specialised techniques such as satellite tracking or leg rings |
| what are the two types of migratory behaviour | innate (inherited)
learned (gained by experience)
sometimes migratory behaviour is a mixture of both innate and learned |
