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Maintaining a Balance
Biology – Stage 6
© Taronga Zoo Education Centre. These sheets may be reproduced for teaching purposes. Permission to reproduce
them for other purposes may be obtained from Taronga Zoo Education Centre.
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This resource is to be used as part of an excursion to Taronga Zoo. The resource
and related workshop is linked to the NSW School Curriculum and has been
developed in consultation with Department of Education and Training Curriculum
Coordinators and NSW School Teachers. It is a comprehensive kit of information
and activities designed to ensure maximum benefit to you during your excursion to
Taronga Zoo.
Contents
Introduction 2
NSW School Curriculum Links 3
Prior Knowledge and Experience 4
At the Zoo 4
Student field notes 5-16
Maintaining a Balance
Zoo
Education
3
NSW School Curriculum Links
Stage 6 Biology
9.2 Maintaining a Balance
Taronga Zoo exhibits a range of animals which will enable students to develop an
excellent understanding of the adaptations animals have to maintain a balance
within the narrow limits for survival.
The activities detailed in this resource address the following syllabus related topics:
• Compare responses of named Australian ectothermic and endothermic
organisms to changes in the ambient temperature and explain how these
responses assist temperature regulation.
• Analyse information from secondary sources to describe adaptations and
responses that have occurred in Australian organisms to assist temperature
regulation.
• Analyse information from secondary sources to compare and explain the
differences in urine concentration of terrestrial animals, marine fish and
freshwater fish.
• Use available evidence to explain the relationship between the conservation of
water and the production and excretion of concentrated nitrogenous wastes in
a range of Australian insects and terrestrial mammals.
The ‘Maintaining a Balance’ excursion to Taronga Zoo also provides students
opportunities to further develop skills in communicating information and
understanding, scientific thinking, problem solving and working individually and in
teams.
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Prior Knowledge and Understanding
It would be most beneficial if students had the following prior knowledge and
understanding before their visit to the Zoo.
- the maintenance of a constant internal environment is important for optimal
metabolic efficiency
- homeostasis
- endothermic and ectothermic
- the process of diffusion and osmosis
- passive and active transport
- the role of the kidney
- the processes of filtration and reabsorption in the mammalian nephron
At the Zoo
Workshop with Zoo Educator
Workshops are approximately 50 minutes duration and include content on how
many Australian native animals maintain homeostasis this is supported and
enhanced with native animal encounters.
Seal Presentation
Seals are exceptional thermoregulators, needing to cope with temperature extremes both in water and on land. Visit the seal show to provide students with an
excellent opportunity to extract information about seal thermoregulation from expert
marine mammal keepers.
Excursion Fieldwork
Copy the following worksheets for your students to complete in their free time at
the Zoo. The questioning is designed to have students apply their knowledge of
thermoregulation and water balance from a captive husbandry point of view.
Students will also be challenged on their ethical attitudes towards keeping animals
in captivity.
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Koala
Provide possible explanations for the koala facts given below in relation to
thermoregulation and/or water balance.
Describe features of the exhibit that assist in the thermoregulation of the koala.
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Suggest what Zookeepers could do to avoid heat stress in koalas on a 40Cº day.
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Activity – nocturnal, sleeps 18hrs per day ……………………………………………………
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No sweat glands, do not pant ……………………………………
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Posture – temperature dependant ………………………………………
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Koala is an Aboriginal word meaning ‘no drink’
Brain size – 0.2% of body weight
.………………………………………
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Faeces – dry pellets Urine – highly concentrated urea ……………………………………………
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Back fur – very high insulation Chest fur- low insulation
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Core temperature - 35-36Cº
Water intake – 400ml per day
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Corroboree Frog
The Corroboree Frog exhibit is kept at a temperature of 5Cº. These tiny frogs can
survive comfortably in temperatures ranging from 0Cº to 30Cº. Suggest a reason
for the deliberate lowering of the temperature of the frogs’ surroundings.
………………………………………………………………………………………………
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Fertilised eggs rapidly enlarge as they fill
with water ……………………………………................
……………………………………................ Lays eggs in sphagnum moss ……………………………………………
………………………………………....... Changes posture when basking ……………………………………
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Uric acid is stored when the frog is out
of water …………………………………………..
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Tadpoles hatch in winter, already with
hind legs and without gills
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Tadpole growth-rate slows over
winter months
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Black-headed Python
Many snakes are ambush predators, spending up to 3 weeks lying motionless to
fool potential prey into approaching. Give an explanation as to how a snake can
do this yet also thermo-regulate so that their body temp is high enough to digest
prey.
………………………………………………………………………………………………
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Some Australian snakes give birth to live young (the eggs hatch before they young
emerge). Hypothesize why this may be an adaptation to cope with cold
temperatures.
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Found in arid conditions
Feeding – greatly reduced in cooler months
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Incubation - coil around eggs and ‘shiver’
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Behaviour - nocturnal in warm weather, diurnal in cold
weather …………………………………………
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Skin is impermeable …………………………………......
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Head section is black
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Basking behaviour
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Lacks sensory heat pits for detecting endothermic prey
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Asian Elephant
An elephant weighing 2000000g has a skin surface of roughly 100000 cm². A
rat weighing 300g has a body surface of 300 cm².
Compare the surface area to volume ratios of these two mammals.
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Make a general statement comparing the ability of large and small animals to give up their
heat?
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Use this information to postulate what would happen if elephants did have sweat glands all
over their body rather than large ears.
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Ear flapping – blood temp drops over
8Cº as it passes through the ears
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Core temperature - 36-37Cº
Skin – 3cm thick on legs and back, paper thin on chest and abdomen
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250 daily litres of water consumed
……………........…………
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Skin surface area is twice as large as
needed
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Dust bathing behaviour
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Throat pouch – contains stored water
which can be drawn out by trunk ......................................
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Sweat glands only found between toes
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Andean Condor
When an Andean Condor drops down to ground for feeding its body may experience a temperature shift from l2Cº to 40Cº. How do you think Andean Condors cope with this extreme?
………………………………………………………………………………………………
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Many folds of bare skin on head
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Birds do not sweat
Body temperature drops by several degrees overnight
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Spreads wings in morning
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Fluff feathers when cold, smooth feathers when hot
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Counter current heat exchange in feet
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Defecates on legs in hot weather
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Retracts bare head into tuft of neck feathers when
flying at high altitudes
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A long way from home
Locate a Zoo animal that is originally from a location/climate markedly different to the climate
and conditions found in Sydney.
1. Draw the animal in its
exhibit.
2. Label the animal with
possible responses the animal may have had in order to cope with its new
environment.
3. Label the features of the
exhibit that have attempted to
assist the animal’s ability to
cope in its new environment.
Do you feel the animal is suitable for Sydney’s Taronga Zoo? Explain.
………………………………………………………………………………………………
………………………………………………………………………………………………
Find out why the animal is part of the Zoo collection.
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Seal Presentation Notes
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Short-beaked Echidna
13
Red Kangaroo
14
Green Tree Frog
15
Shingleback Lizard
16
Saltwater Crocodile