Investigative Biology Flashcards
Describe the scientific cycle
Construction of a testable hypotheses Experimental design Gathering, recording and analysis of data Evaluation of results Conclusion
A sound scientific hypothesis…
Must be based on established data
Can be tested
Can be proven false
Data can be collected in the form of…
Observations (see, smell, hear, taste, touch)
Measurements
Scientists analyse data for….
Trends or patterns
After a trend in the results is found…
You must accept, revise or reject the hypothesis based on the data from the experiment and continue to analyse until the hypothesis seems sound
Negative results are produced in two cases:…
Hypothesis is wrong
Experiment carried out incorrectly
Failure to find an effect is a valid finding as long as…
An experiment is well designed
Null hypothesis
A statement which proposes that there will be no statistically significant effect as a result of the experiment
Scientific ideas only become accepted once they have been…
Peer reviewed ( checked independently)
Communication within the scientific community is incredibly important. It allows findings to be shared with others to further their research.
It is important that…..
Methods data, analysis and conclusions are published in scientific reports so the others are able to repeat an experiment
Name ways in which scientific findings are shared
Seminars Talks Posters Confrences Academic journals
Review articles
Scientific journals summarise current knowledge and recent findings in a particular feild
All published data should be….
Peer reviewed and critically evaluated with expertise in the relevant field. This ensures scientifically correct information is being shared within the community
Science stories in the media are often….
Misrepresented So coverage must be critically evaluated
Ethics
Ideas and beliefs about what type of behaviour is morally right or wrong
Science relies on the reporting of….
Unbaised presentation of results, citing and providing references snd avoiding plagiarism
The replication of experiments by others reduces
The opportunity for dishonesty or the deliberate misuse of science
The three Rs
Replacement
Reduction
Refinement
Replacement
Replacing the animal with an alternative such as tissue cultures or a less sentient species
Reduction
Using the minimalist number of animals in order to obtain results
Refinement
Using methods that minimise potential pain, suffering or distress on animals
When using human subjects there are several concepts that must be used to ensure human rights are adhered to
In formed consent
The right to withdraw
Confidentiality
The right to withdraw
The participants have the ability to remove themselves from a trail at any time during the study
Confidentiality
Any data does not identify the subject and they can remain anonymous
Data is not shared without their consent
Risks in a scientific experiment must be considered for the safety of the…
Subject species
Individuals
Investigators
Environment
Legislation
Laws governing various aspects of science, legislation limits the potential for misuse of studies or data
What can influence scentific research
Legislation
Regulation
Policy
Funding
The value or quality of scientific investigations must be justifiable in terms of…
Benefits
As a result of the risks involved many areas of scientific research are…
Highly regulated and licensed by governments
Validity
Variables controlled so that any measured effects is likely to be due to the independent variable
Reliability
Consulate values are active in repeates and independent replicates
Accuracy
Data, or means of data sets are close to the truest value
Precision
Measured values are close to each other
Pilot study
Small scale preliminary studies which aim to investigate whether crucial components of a study will be testable
Pilot studies are essential to…
Plan procedures, asses validity, check techniques and help evaluate and modify experimental design
Pilot studies ensues appropriate values for
Independent variables
No. Of repeat measurement
Variable
Any factor that can be controlled changed or measured in an experiment
Continuous variable
Can take on infinity, many, uncountable values
Eh. Length , concentration, wavelength
Discrete
You can have a finite range of values
Colour, presence/absence, shoe size
Experiments involve the manipulation of the… by the investigator
Independent variable
Independent variable
Variable that is changed in a scientific experiment
Dependent variable
Variable that is measured in a scientific experiment
An experimental treatment will me compared to a….
Control group
What is a drawback of simple experiments
It’s findings may not be applicable in the field
Multifactorial experiment
Involves a combination of one independent variable or combination of treatments
Confounding variable
Variables that may affect the experiment but are not independent or dependent
In cases where a confounding variable cannot be controled……
a randomised block design could be used
Control
An experimental group where no treatment is given
Negative controls
Provides results in the absence of treatments
Positive controls
A treatment that is included to check that the system can detect a positive result when it occurs
Placebos
Included as a treatment without the absence of the independent variable being investigated.
Placebo effect
A measurable change in the dependent variable as a result of patients expectations rather than changes in the independent variable
In vivo
Experimentation using a whole living organism
In vitro
Performing a given procedure in a controlled environment outside of a living organism
What is an advantage to in vitro
Better control of your experiment and any confounding variables
What is an advantage to in vivo
Better idea of what is going on inside the cell or organism
What is an disadvantage to in vitro
Not possible for many studies
Does not show effect on non target cells
What is an disadvantage to in vivo
Living organisms show great variability which can’t really be controlled
Representative sample
A sample which shows the extent of the natural variation within a population
More variable populations require a larger sample size
Should have the same mean and degree of variation
Random sampling
Members of the population have an equal chance of being selected
Systematic sampling
Members of the population are selected at regular intervals
Stratified sampling
The population is divided into categories that are sampled proportionally
Variation in experimental results can be caused by
Realisability of measurement methods
Inherent variation in specimens
Precision and accuracy of repeated measurements
The reliability of measuring instruments or procedures can be determined by…
Repeated measurements or readings of an individual datum point
Qualitative data
Data which is subjective and descriptive
Quantitative data
Data that can be measured objectively, equally with a numerical value
Ranked data
Data transformation in which numerical values are replicated by their rank when data is sorted from lowest to highest
Mean
The average value of data
Median
The middle value
Mode
The most common value
Error bars
Graphical representations used to indicate error or uncertainty in a reported measurement
Correlation
An association that does not imply causation
Positive correlation
When an increase in one variable is accompanied by an increase in the other
Negative correlation
When an increase in one variable is accompanied by an increase in the other
Scientific reports should contain
Explanatory title
Abstracts (aims and findings)
Introduction
Sources (supporting statements, citations and references)
An Aim must….
Link the independent and the dependent variables
The introduction should…
Why the study has been carried out
Place the study in the context of existing understanding
A method should contain
Sufficient information to allow another investor to repeat the work
Should address the intended aim and test the hypothesis
Allow treatment effects to be compared to the controls
Any compounding variables should be…
Taken into account or standardised across treatments
The validity of an experiment may be compromised when…
Factors other than the independent variable influences the value of the dependent variable
An experimental design that does not address the intended aim or test the hypothesis is…
Invalid
Selection bias
The selection of a sample in a non-random way, so that the sample is not representative of the whole population
If the sample size is too small…
It cannot be decided without bias whether the change to the independent variable has caused an effect in the dependent variable
Statistical tests
Used to determine whether the differences between the means are likely or unlikely to have occurred by chance
A statistically significant result is one that…
Is unlikely to have occurred due to chance alone
Error bars do not overlap
Conclusions should include…
Reference to the aim, the results and the hypothesis
The validity and reliability of the experimental design
Whether results can be attributed to correlation or causation
Evaluations should include
Reference to existing knowledge and the results of other investigations
Reveal awareness of the contribution of scientific research to increasing scientific knowledge and to the social, economic and industrial life of the community
