Required Practical Technique Flashcards
How should ratios be exoressed in biology?
X:1
How does repeating experiments increase reliability?
Allows means to be calculated
Anomaly results are identified and their effects are reduced
Why is expressing data as a ratio beneficial?
It allows results to become proportional and therefore comparable. Despite them having different starting values
What is extrapolation and why can it not be used on graphs?
Extrapolation is continuing a line of best fit past the first/ last values. It cannot be used as the data for any values not used cannot be known or predicted.
State 5 rules for biological drawings
Lines should all be joned, no hanging lines
Lines should not cross
No shading
No sketching
Not too much/ too little detail
Why should straight lines be used between points when drawing a line of best fit?
You cannot predict the data between values if there are is no intermiediate data
On a graph, when should you draw a dot to dot line and a straight line of best fit?
Dot to dot when there is not clear relationship between variables
Straight line when there is a clear trend pr relationship
What is the dofference between correlation and causation?
Correlation shows there is a relationship between two variables
Causation is when one variable effects/ is effected by another variable.
Correlation does not mean causation
What is the three types of variables?
Controll- stays the same
Dependent- what is being measured every time the independent variable is changed
Independent- what changes during the investigation
How is correlation describe?
Strong/ weak - depending on how close together all dots are.
Positive- as variable 1 increases variable 2 increases
Negative- as variable 1 increases variable 2 decreases
What should be on a biological drawing?
Labelled key parts
Correct scale stated
Drawing that is similar to origional
No hanging lines
