Welcome to FLIS Biology 3A
Biology: fields of studyUse the highlighter pen to match each type of scientist to the picture of what they study
• Botanist• Ecologist• Entomologist• Herpetologist• Ornithologist• Palaeontologist• Zoologist
Biology: fields of studyUse the highlighter pen to match each type of scientist to the picture of what they study
• Botanist• Ecologist• Entomologist• Herpetologist• Ornithologist• Palaeontologist• Zoologist
What is biology?
Biology is the study of living things and their interactions with each other and the non-living environment.
Biology is a science• Science is a body of knowledge (what
we have found out)• Science is also the process by which
we gain the knowledge (how we find out)
The Practice of Biology
• Introduces the skills you need as a scientist• Provides the tools or processes you will use to
study biology• Is assessed across all modules in the course
What do scientists do• Scientists collect data• Scientists analyse and organise
their findings• Scientists share their findings
The scientific method
Defining problems for investigation
• Making observations
• Asking questions and making inferences
Investigating to find answers
• Forming hypotheses
• Making predictions
• Testing the hypotheses
Making conclusions and sharing them
Observations and inferences
Observations and inferencesObservations – The cage is emptyThere are feathers on the groundThere is a cat
Inferences - The cat has eaten the bird There wasn’t any bird – the cat has been framed
Quantitative and qualitative observations
Quantitative – using measurements Qualitative – descriptions eg colour, shape, roughness, shine, etc
Making observations
Quantitative observations areExamples include
Qualitative observations areExamples include
Qualitative Quantitative
Making observations
Quantitative observations are observations that can be measuredExamples include length, width, mass, temperature, speed, humidity
Qualitative observations are observations that can’t be measuredExamples include colour, shape, texture, size (eg large or small)
Qualitative Quantitative
BrownHas furLargeEats grassHas claws
Height at shouldersBody lengthBody massBody temperatureMeasurements of teeth, claws, etcMeasurements of food volumes
Designing experiments
When we design experiments we need to define how we intend to measure and collect results before we even start the experiment.
What’s going on here?
• Pose a question
• Suggest some answers
Define your hypothesisEg – the more detergent in the mix, the more bubbles we getThe bigger the wire loop, the bigger the bubbles produced
What shall I change?
• Select one thing to test
• How will you change it?
Define your independent variableEg changing the amount of detergent, the size of the loop, the type of water used, etc
How do I know if it has an effect?
• What will I measure?
• How will I measure it?
Define your dependent variable
• What will I compare it to?
Define your control
Eg size of bubbles – rulerStrength of bubbles – time they lastNumber of bubbles
Experimental and control groups eg low detergent against high detergent,Hard water against rain waterBig loop against small loop
How do I know my results are true?
• What do I need to keep the same?
Define your controlled variables
• How can I make the experiment fairer?
Define how you will increase reliability
Eg Repeat the experimentGet others to replicate
Ways to increase reliability
• Use accurate measurements
• Repeat the experiment
• Increase the sample size
• Get someone else to replicate the experiment
• Share the results and get a review
The language of experimental design
• Hypothesis – statement to be tested by experiment – links independent and dependent variable eg bigger loops make bigger bubbles
• Independent variable – the thing you change eg the size of loop
• Dependent variable – the thing you measure eg the size of bubble
• The control – what you compare the experimental group to
• Controlled variables – the things that are kept the same in both experimental and control groups
• Reliability – measures to increase the fairness of the experiment
Problems with measurement
Using them properly
Using the right instrument
Accuracy in measurement
• Calibrate your equipment
• Use the right equipment for the job
• Use the equipment properly
Why is precision important?
Look at the examples below.
How would you measure their size?
Why is precision important?
Look at the examples below.
How would you measure their size?
When designing experiments, you often need to define how the measurements need to be taken, as well as the instruments that are to be used.