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.