VCE Biology Unit 2Area of Study 01

Adaptations of Organisms

Environmental factors and adaptations

Challenge to survival

Living organisms require:• Nutrients• Water• O2 and CO2

• Light• TemperatureTolerance Range (for each requirement) is range where organism is functioning most efficiently

Challenge to survival

Environmental factorsPhysical – abiotic environment• Soil• Rainfall• Temperature• Salinity etc.

Challenge to survival

Environmental factorsBiological – biotic environment• Predators• Food (prey)• Mates• Competitors

Challenge to survival

Anyone of these factors can be the ‘limiting factor’ (i.e. the one that is limited in supply). E.g. water, food, mates, etc.Tolerance range affects distribution. E.g. Change in temperature may lead to a change in distribution of a particular plant species.

Challenge to survival

Adaptation:Organism show a change in physiological (functional), anatomical (structural) and/or behavioural adaptations that allow them to survive and reproduce in changing conditions (both external and internal).An adaptation is an inherited change in characteristics that increases the chance of survival and reproduction in a changing environment.

Challenge to survival

Acclimatisation:This is NOT adaptationThis is a temporary change to an organism’s physiology and is not inherited.E.g. Climbing Mount Everest – Acclimatise at camps at different altitudes. Haemoglobin increases due to decrease in O2. Changes back afterwards.

13.1 Challenge to survival

Australian Environments:Terrestrial (land) and aquatic (fresh water and marine).

Challenge to survival

Australian Environments:Terrestrial (land) North East coast (Northern Queensland and Eastern Northern Territory) – tropical, wet summers (2,000 mm of rain per year).South coast – temperate, cool winters, temperatures range from -2°C to 43°C. Inland – semi-arid to desert. High temperatures, low rainfall.Old continent – low levels of nutrient in soil.

Challenge to survival

Australian Environments:Aquatic (fresh water and marine) – fresh rivers and inland lakes can dry up in summer. Marine varied conditions. North – tropical coral, South cold rugged, rocky coastline.