Unit 3- Investigative Biology Flashcards
What is a hypothesis?
A prediction on how the independent variable will affect the dependent variable.
What does the null hypothesis propose?
There will be no effect from varying the independent variable.
What are the 3Rs for ethics in animal studies?
Replacement- animals should be replaced with alternatives as often as possible.
Reduction- the number of animals used in the study should be reduced as much as possible.
Refinement- for animals being used the negative impact should be minimised.
What is the Nuremberg code?
Informed consent, right to withdraw (any time up until point of publication), confidentiality (data must be anonymous).
What are pilot studies used for?
To develop and practice protocols ensuring validity of experimental design.
Check effectiveness of techniques.
Find a suitable range of values for the IV.
Identify and control confounding variables.
Identify a suitable number of replicates.
What are confounding variables?
Confounding variables are variables that may impact your dependent variable other than your independent variable therefore making the experiment invalid if they are not controlled.
What is a positive control?
A positive control anticipates a pre-defined change and is done to negate false negative results.
What is a negative control?
A negative control anticipates on change and is done to negate false positive results.
What is an in-vivo investigation and the advantages and disadvantages?
When the studies are conducted in animals, including humans and whole plants. This allows you to see the effect of something on the whole organism e.g. with a drug trial you can identify any potential side effects. However, it is more difficult to control confounding variables.
What is an in-vitro investigation and the advantages and disadvantages?
When the study is conducted with microorganisms outside their normal biological context. These experiments are simpler as it is easier to control confounding variables however the results may not be applicable to a wider setting.
What should a representative sample share?
A representative sample should share the same mean and the same degree of variation about the mean as the population as a whole.
Define accuracy
This is how close you are to the true value of the data.
Define Precision
This is the closeness of your repeated values to one another.
Define Validity
This refers to whether the conclusions drawn from the set of results are credible. Valid results rely on sound experimental design and execution. Results are considered valid of all confounding variables have been controlled, therefore only the independent variable affected the dependent variable.
Define Reliability
This refers to whether a procedure yields consistent results each time it is repeated. Carrying out repeat measurements within an investigation can improve the reliability of the results. A result is considered reliable if it can be reproduced by both the initial researcher and other scientists.
