Depth Study (Practical skills) Flashcards
(13 cards)
Hypothesis
If (defined conditions are met), then (expected outcome), becuase (scientific theory)
- Defined conditions : appropriate controlled variables and the independent variable
- Expected outcome : statement relating IV and DV in a relationship that can be tested
- Scientific theory : stated but followed with a sentence explaining detail of relationship that
supports prediction
BIO11/12-1 develops and evaluates questions and hypotheses for scientific investigation
What is the independent variable (IV)?
Justify and evaluate the use of variables and experimental controls to ensure that a valid procedure is developed that allows for the reliable collection of data.
The variable you change.
E.g temperature in an enzyme reaction.
What is the dependent variable (DV)?
Justify and evaluate the use of variables and experimental controls to ensure that a valid procedure is developed that allows for the reliable collection of data.
The variable you measure.
E.g time taken
What are controlled variables?
Justify and evaluate the use of variables and experimental controls to ensure that a valid procedure is developed that allows for the reliable collection of data.
The variables kept constant to prevent them from affecting the results by influencing the (DV), –> makes it unclear whether results are due to IV or something else.
Risk table
Identify
Assesses risks, consider ethical issues and select appropriate materials and technologies when designing and planning an investigation.
Name a risk to a person and what it will cause to them.
E.g scalpel has sharp blade that can cause lacerations to fingers.
Risk table
Assess
Assesses risks, consider ethical issues and select appropriate materials and technologies when designing and planning an investigation.
Assess the likelihood and extent of the damage, medical? (+risk)
E.g. moderately likely to occur causing minor injuries that may require medical attention.
Risk table
Control
Assesses risks, consider ethical issues and select appropriate materials and technologies when designing and planning an investigation.
What can be done to minimise the risk
E.g use forceps, cut away from the body, cut on a surface such as dissecting tile.
Validity, how to ensure?
Does the experiment test the aim?
How to ensure:
* Does it test the hypothesis?
* Only IV changed to draw meaningful conclusions
* All other factors are controlled
* Validity is ensured by reliability + accuracy
Reliability, how to ensure?
The experiment can be repeated and achieve the same results.
How to ensure:
* experimental control
* replication (through trials) - minimises random errors
Accuracy and precision, how to ensure?
Accuracy: The ability to obtain correct measurements by minimising systematic errors.
Precision: The ability to consistently obtain the same measrurement by minimising random errors.
What is and jusitfy the use of an experimental control? What does it increase?
Justify and evaluate the use of variables and experimental controls to ensure that a valid procedure is developed that allows for the reliable collection of data.
A baseline set up where the (IV) is not applied, allowing to compare results and determine whether changes in the (DV) are truly due to the (IV)
- ensures validity
What is the experimental control in gel electrophoresis?
Justify and evaluate the use of variables and experimental controls to ensure that a valid
procedure is developed that allows for the reliable collection of data
The DNA ladder is the experimental control, containing DNA fragments of known sizes.
It increases validity and accuracy by providing a reference for fragment size comparison.
Why is it difficult to improve reliability in gel electrophoresis?
Justify and evaluate the use of variables and experimental controls to ensure that a valid
procedure is developed that allows for the reliable collection of data
Because it’s a destructive process and there may be limited DNA samples, making repetition difficult.
