Scientific Method Flashcards
List 4 reasons why people should be concerned about environmental degradation and explain why they are important:
Healthy ecosystems provide a wide range of goods and services for humans
A degraded environment has less aesthetic value/tourism value
It is not ethically acceptable for one generation to destroy environmental assets so they are unavailable for future generations
Environmental degradation is often a cause of species becoming threatened or extinct
What are the most pressing problems facing the leadbeaters possum?
Available nesting hollows in areas with suitable food sources
Competition with logging industry
Corrigan grevillea habitat reduction - security of the population on a road verge, genetic erosion due to population size and no new recruitment of new plants from seedlings
Why was there such a controversy concerning possible impacts of the crown of thorns starfish on the GBR?
Dispute over whether the starfish outbreaks had a natural cyclical occurrence with no deleterious effects and possible benefits to coral diversity, or a result of the recent introduction of the animal and causing damage from which the corals would not recover.
Outline main steps in hypothesis testing:
Make an observation (all science aims to explain phenomena in the natural and physical world)
Design a model or propose an explanation (you can only make a scientific investigation if you have some reasonable, testable idea of what might be causing the observation)
Design null hypothesis (a hypothesis can be refuted not proven)
Design experiment - determine what are the dependent and independent variables, the number and size of replicates needed, and appropriate controls (this planning is needed for all experiments)
Do experiment
Test data statistically (test whether your observations could be caused by chance variations and if the experimental treatments are significantly different from controls)
State whether or not the null hypothesis has been supported
What is meant by replication and why is it important?
Tests of multiple samples or at multiple sites are required so we can be sure that a difference between the control and the treatments is not due to a factor other than what you were testing. This is particularly important when dealing with living organisms that may be genotypically variable and thus show a range in response to any treatment.
What is meant by controls and why are they important?
Controls are the baseline against which change caused by experimental treatments can be assessed. They should be exactly the same as the treated group except for the one factor being assessed for effect. Without controls it is not possible to know if a change is caused by the experimental treatment or some other factor.
