Key area 5: Metabolism and adverse conditions

1. Key area 5: Metabolism and adverse conditions

2. Learning intentions: By the end of this topic you should be able to: • Explain why organisms avoid adverse conditions and give examples of how they do this. • Understand and define the terms dormancy, hibernation, aestivation and daily torpor. • Describe what is meant by the term extremophiles and give examples. • Give at least one use of extremophiles.

3. Surviving adverse conditions • Many environments vary beyond tolerable limits for normal metabolic activity for any particular organism. • Adverse conditions can include extreme temperatures or lack of water. • The normal metabolic rate of an organism can be costly in these conditions. • In order to survive, metabolic rate is reduced.

4. In pairs, think about ways in which animals might avoid these adverse conditions.

5. Dormancy • The development of an organism is temporarily suspended, minimising metabolic activity and therefore saving energy, until the environmental conditions improve. • Dormancy is part of some organisms’ lifecycle. • There are two types of dormancy: Predictive dormancy Consequential dormancy

6. Predictive dormancy • Predictive dormancy: an organism enters a dormant phase before the onset of adverse conditions e.g. decreasing temperature or day lengths can be used as cues. • Most common in areas where conditions are predictable and consistent

7. Consequential dormancy • Consequential dormancy: an organism enters a dormant phase after the adverse conditions have arisen. In areas where conditions are varied and unpredictable.

8. Examples of dormancy • Hibernation: response of an animal to avoid adverse conditions by reduction of metabolic rate. • Normal body functions of an organism change dramatically during hibernation e.g. the heart rate of a jumping mouse falls from 600 beats per minute to 30 beats per minute.

9. Dormancy in animals: Hibernation • May last for weeks/months. • Often predictive – animal consumes extra food which is laid down as a fat store. • Metabolic rate drops which allows body temperature to drop to surrounding temperature. • Slower heart and breathing rate, minimal energy expenditure.

10. Hibernation video clips • Dormouse hibernation • Living Britain • Hazel dormouse fatten up for a winter sleep. • Frozen turtles • Life in Cold Blood • Painted turtles have a natural anti-freeze that helps them survive winter. • Winter warming • Living Britain • Creatures escape the extremes of winter by taking refuge in our houses. • Siberian hibernation • Realms of the Russian Bear • Many animals hibernate in burrows to survive the winter months of Siberia.

11. Examples of dormancy • Aestivation: allows survival in periods of high temperature or drought. The process typically involves burrowing into the ground where the temperature stays cool, and reducing metabolic activity in a similar manner to hibernation.

12. Aestivation • Desert amphibians • Life in Cold Blood • Australian spadefoot toads rise like zombies at the first rain. • Underground crocs • Inside the Perfect Predator • Crocodiles go into suspended animation to wait out the drought. • A quiet summer home • First Eden • Snails and Jersey tiger moths have a restful summer on Greek islands.

13. Examples of dormancy Daily torpor: a short period (eg. part of a day) of reduced activity in organisms with high metabolic rates. It involves a reduction in heart rate and breathing rate. e.g. house mice are active during the night and experience torpor through the day when it would be dangerous for them to be out in the open foraging for food.

14. Hummingbirds feed during the day and exhibit torpor at night. Daily torpor • Animal's rate of metabolism and activity become greatly reduced for part of every 24-hour cycle. • Accompanied by a slowing down of heart and breathing rate and decrease in body temperature. • All of these animals have a large surface area through which heat (and therefore energy) is lost. Bats and shrews feed at night and become torpid during daylight hours

15. Match the form of dormancy with the correct description

16. Avoiding Adverse Conditions

17. Migration • Migration is a seasonal movement from one area to another. • The expenditure of energy to relocate is a disadvantage to the organism in the short tem but is beneficial in the long term. • Organisms that migrate include swallows, whales, geese, caribou, osprey, salmon. • Migration triggers – daylength, temperature, hormonal changes

19. Migration - clips • http://www.bbc.co.uk/nature/adaptations/Nomad#p00cnsjw • Painted lady butterfly migrates in search of food. • Himalayan migrationRealms of the Russian Bear. A big mountain range won't stop these birds on their migration. • Migrating eelsAutumnwatch • The eel's incredible life history explained.

20. Migration - clips • Siberian cranes make their annual 9,000km trip from northern Siberia. Poyang migration • Desert elephantsThe epic journey of these land giants is dwarfed by Namibia's vast, empty dunes. • Migration from the cold Realms of the Russian Bear. When the winter sets in, it is time to move further south. • Kings of long-haul Journey of Life. Monarch butterflies cover thousands of miles from Canada to Mexico. • Arctic to Antarctic Arctic terns • Arctic terns migrate 12,000 miles to fish where the sun doesn't set

21. Tracking Migration

22. Migration studies activity • Go to the migration research foundation website or Scholar. • Take notes on the methods used to study migration. • Feed your findings back to the class.

23. Individual marking • Ringing (or banding) uses a metal band with the bird’s unique number and the investigator's contact details) attached to the bird’s leg. • Can provide useful information if the bird is recaptured and the information is reported.

24. Tagging • This tag attached to the underside hind wing of a Monarch butterfly carries a code which has been entered into a database. • If the tag is recovered later, the route and distance covered by the butterfly can be discovered.

25. Coloured tags • Good for spotting birds from a distance using binoculars.

26. Tracking using transmitters • Lightweight transmitters are glued to the animal's body or implanted under its skin. • Transmitter emits signals that are picked up by receivers on satellites orbiting Earth. This signal is beamed back to ground stations on Earth.

27. Tracking using satellite transmitters • Excellent for tracking migratory routes used by birds and sea mammals (whales and seals). • But expensive and may cause drag on some small birds.

28. Tracking using radio transmitters • An be attached to very small animals as well as large e.g butterfly to polar bear. • Invertebrates can have it attached to shell but can become an issue when they shed. • Requires a tracking radio signal.

29. Tracking using transmitters • How to track a killer whale • Frozen Planet • Frozen Planet worked with expert Antarctic boat skippers and killer whale scientists to capture a remarkable behaviour.

30. Learned behaviour Innate and learned influences on migratory behaviour Innate behaviour Inherited and inflexible Plays a primary role in migratory behaviour Performed in same way by every member of species Occurs in response to an external stimulus such as a change in photoperiod. Begins after birth and gained by experience. Flexible and a result of trial and error and relearning from members of a social group Plays a secondary role in migratory behaviour

31. Extremophiles • An extremophile is an organism that lives in an environment with extreme abiotic conditions – heat (high/low), pH (acid or alkaline), chemicals (methane/salt) • On Earth these sorts of conditions can be found in the deep sea, volcanic vents hot springs, glaciers.

32. Match up the numbers of the extremophiles in the diagram with the type of extremophile and its description. Alkaliphiles - microbes that live in basic environments such as soda lakes. Halophiles - microbes that live in very salty environments such as salt lakes and salt mines. Thermophiles - microbes that live in very hot environments such as deep sea vents and volcanic lakes. Psychrophiles - microbes that live in cold environments such as sea ice, and the Arctic and Antarctic ice packs. Acidophiles - microbes that live in acidic environments such as sulphur springs.

33. Examples of extremophiles • Pompii worm (multicellular example) • They are thermophiles living in deep sea vents. • They form a symbiotic relationship with bacteria. • They produce a mucus coat which feeds bacteria. • The bacteria provide thermal insulation. • The bacteria have also been shown to contain enzymes which are able to tolerate wide extremes of temperatures

34. Pompii worm

35. Examples of extremophiles Some extremophiles have adapted their method of generating ATP to suit their habitat. E.g. some species living in hot springs or seabed vents generate their ATP by removing high-energy electrons from inorganic molecules such as hydrogen sulphide. They can use these high energy electrons to generate ATP using ATP synthase.

36. Uses of extremophiles • Thermophiles have provided scientists with opportunities to extract enzymes which are stable at high temperatures. • One example is Taq polymerase (found in thermophilic bateria) which is used in the polymerase chain reaction (PCR) used in forensic genetic fingerprinting and medical diagnosis. • The Taq works at quite high temperatures but also is not denatured by the very high temperature needed to denature the DNA strands.

37. How much do you know? Higher Biology for CfE P185 Testing Your Knowledge 2 Q1-4 Applying Knowledge and Skills P43 Q1-7

38. Key words • Aestivation • Dormancy • Consequential dormancy • Extremophile • Hibernation • Innate behaviour • Learned behaviour • Migration • Predictive dormancy • Thermophilic bacteria • Torpor

39. Extended Responses Give an account of the adaptations of organisms to surviving and avoiding adverse environmental conditions. Give an account of extremophiles.