Scientific Method Flashcards
What is the purpose of replicates in scientific experimentation?
Ensure reliability
What is meant by the term hypothesis
Educated guess based on observations
Give two examples of limitations of the scientific method
Accidental discovery
The extent of our basic knowledge
Changes in natural world
What is the purpose of a hypothesis in the scientific method
Forms basis of a prediction
What should be accounted for in a hypothesis?
All the facts that have been observed
Explain what is meant by double-blind testing
Neither the experimenter nor the test group knows who gets what
What’s the purpose of double blind testing / explain the importance of it
The tester cannot influence the results of the experiment - avoid bias
Why is a control essential in scientific experiments?
As a comparison with experiment
Where do scientists usually publish the results and conclusions of their investigations?
Scientific journals
How does a hypothesis differ from a theory?
Hypothesis can develop into a theory when has been supported by many different experiments
How does a hypothesis differ from a theory?
Hypothesis can develop into a theory when has been supported by many different experiments
What is data
Observations or results gathered from experiments
What are replicates
Repeat of an experiment
In an experiment to investigate effect of concentration of iodine on rate of growth of 100 tadpoles,all same age from same mother [2015]
Why do you think that it was important that all the tadpoles came from the same mother?
So they’re genetically similar - act same way
Minimises variation
In an experiment to investigate effect of concentration of iodine on rate of growth of 100 tadpoles,all same age from same mother [2015]
Suggest why he used 25 tadpoles in each group
- larger sample would allow for illnesss
- make results more statistic significant
In an experiment to investigate effect of concentration of iodine on rate of growth of 100 tadpoles,all same age from same mother [2015]
Suggest how this investigation would have been carried out
- diff concentrations of iodine solution used
- one is control, with no iodine
- in each solution, put 25 tadpoles
- leave for time and record changes
In an experiment to investigate effect of concentration of iodine on rate of growth of 100 tadpoles,all same age from same mother [2015]
Suggest two factors that the scientist would have kept constant during investigation
Temp
Volume of water
What is an experiment?
Test of hypothesis
What is a theory?
Hypothesis that has been supported by many different experiments
Scientists investigated the effect of a certain mineral on the growth of wheat [2011]
Suggest a reason why the seeds used were all taken from one parent plant
Genetically similar - minimises variation
Scientists investigated the effect of a certain mineral on the growth of wheat [2011]
The compost was sterilised, suggest a way in which might have been sterilised
Heat
State one reason why it is important to sterilise
To kill organisms and prevent contamination
Scientists investigated the effect of a certain mineral on the growth of wheat [2011]
Why did the scientists divide the young wheat plants into two equal groups?
Control - comparison
Scientists investigated the effect of a certain mineral on the growth of wheat [2011]
Kept two groups of plants under identical conditions, why??
Have only one variable + ensure fair test
Scientists investigated the effect of a certain mineral on the growth of wheat [2011]
Name two conditions you think scientists would have kept constant during experiment?
H20
Temp
Why do scientists repeat the investigation several times before publishing their results in a scientific journal?
Ensure reliability
If a scientist wished to determine the effect of a certain herbicide on weed growth she would include a control in the investigation. Suggest a suitable control in this case
No herbicide
What is science?
Organised and objective study of the physical, material and living world.
What is biology?
The study of living things
What is an organism?
A living thing
What is the scientific method?
It is a process of investigation in which problems are identified and their suggested explanations are tested by carrying out experiments
What are the seven steps of the scientific method?
- Observation
- Hypothesis
- Experimentation
- Collection and interpretation of data
- Conclusion
- Relating the conclusion to existing knowledge
- Reporting and publishing the results
How are observations obtained?
Directly by our senses or indirectly by the use of equipment
What is an observation?
Noticing things in our environment
What is the purpose of observations?
Provides basis for all the facts relating to a problem
What can be the two results of an experiment?
-support
-contradict
the hypothesis
How is a conclusion reached?
When the data from an experiment is interpreted
What should the conclusion of an experiment tie in with?
The existing knowledge of the topic being examined
On the basis of the conclusion reached, how is the hypothesis supported?
If results agree fully
On the basis of the conclusion reached, how is the hypothesis changed?
If the results agree only partly
On the basis of the conclusion reached, how is the hypothesis rejected?
If the results contradict it
Why are experiments published?
In order to allow them to be repeated - conclusions are more likely to be valid
Why are results of experiments reported?
So they can be examined and analysed by others
What is a principle/law?
Theory that has been shown to be valid when fully tested over a long period of time
What is the importance of the principles of experimentation?
Ensure experiments are conducted fairly
What are the four principles of experimentation?
- Careful planning and design
- Ensure the experiment is safe
- Design a control experiment
- Fair experiment
What is a variable?
It is a factor that may change in an experiment
How do you ensure that the experiment is safe?
- tie back long hair
- wear lab coat
- avoid contact between electrical equipment and water
- wear safety goggles when necessary
- be aware of safety information when using chemicals
What is a placebo?
It is a tablet or pill that does not contain the factor to be tested
What is the importance of a large sample?
It reduces the risk that the results are due to individual differences rather than being caused by the factor being investigated
When selecting a sample to be tested, what’s necessary?
Random - fair test
What are ethics?
It relates to whether conduct is right or wrong
What are the main areas of disagreements tend to be based on?
- use of captive animals in experiments
- origin of life
- cloning animals
- use of stem cells from embryos to form new tissues or organs
