Unit 2 KA5 Flashcards
Adverse
Unfavourable or disadvantageous
Structural adaptation
A modification to body structure to improve survival chances
Physiological adaptation
A change to the body’s internal processes or chemical reactions to improve survival chances, eg. dormancy.
Behavioural adaptation
A change in an animal’s behaviour to improve its survival chances, eg. migration or huddling in penguins
Dormancy
An organism’s metabolic rate decreases to the minimum level required to sustain life, in order to survive a period of harsh (adverse) conditions by saving energy. In mammals, there is a reduction in body temperature, breathing and heart rate.
Predictive dormancy
Occurs before the arrival of adverse conditions, eg. trees shedding their leaves in the autumn due to decreasing day length.
Consequential dormancy
An organism becomes dormant after the arrival of adverse conditions, eg. aestivation in lungfish
Hibernation
A period of dormancy used to survive harsh winter conditions.
Aestivation
A period of dormancy used to survive high temperatures or drought.
Daily torpor
A period of reduced activity within a 24 hour period, used by animals with very high metabolic rates to conserve energy. eg. bats
Migration
The regular movement of members of a species from one place to another, over a long distance to avoid low temperatures and food shortages. eg. humpback whale, monarch butterfly.
Involves the expenditure of large quantities of energy, so the benefit of migration must outweigh the cost.
Studying migration
Bird ringing, coded tags, coloured bands or satellite transmitters are used to track migratory species in order to learn about their route, the timing of migration and details of the individual animals.
Innate behaviour
Behaviour that is inherited from parents.
It is inflexible, and is performed in the same way by every member of a species, in response to an external stimulus eg. day length
It is the main factor influencing migration.
Learned behaviour
Begins after birth/hatching and is gained by experience and trial and error learning.
It can be learned from parents or members of a social group, and is more flexible than innate behaviour.
It has a secondary role in influencing migration.
Displacement experiment
Birds are captured on their migration route, and are transported somewhere else before being released.
Juveniles continue on the same course and get lost (innate behaviour only)
Adults change course as a result of experience (innate behaviour is modified by learning)
Ink pad experiment
Birds that have been hatched in an incubator and kept apart from their parents show an innate tendency to fly in the same direction.
The direction can be recorded on a filter paper cone above a cage with an ink pad on the floor.
Cross fostering experiment
Eggs from the nests of non-migratory herring gulls are swapped with eggs from the nests of migratory black backed gulls.
The herring gull chicks follow their migrating foster parents.
The black backed chicks left their foster parents and migrated, leaving their parents behind.
This shows that innate behaviour is a more important factor influencing migration than learned behaviour, but both have an influence.
Tolerable limits
Conditions beyond which homeostasis is no longer able to maintain a constant internal environment. eg. extreme heat/cold.
