SBA Biology Conference 2013

Lau Kwok Chi SBA biology supervisor

Verification experiments

Does photosynthesis need light/CO2?

• Verify a concept that has been learned

• Not a real investigation: - No real life problems to investigate! - No new concepts to learn!

• Only require process skills

Scientific Process Skills

• Identify question • Set hypothesis • Design experiment • Present results • Draw conclusion • Manipulative skills

How much?

Two aims/kinds of investigations

Investigation for concept learning – learn about new biology concepts

Investigation for problem solving – apply concepts in solving

everyday problems

Lipase activity and fat in milk

Phenolphthalein is an indicator that is pink in alkaline solutions of about pH10. When the pH drops below pH 8.3 phenolphthalein goes colourless.

Source: http://www.nuffieldfoundation.org/practical-biology/investigating-effect-temperature-activity-lipase

Different designs of the investigation

Concept learning : • Enzyme properties, fat digestion,

emulsification Problem solving : • Does skimmed milk have less fat? • Does soy milk have less fat?

Two aims/kinds of investigations

Investigation for concept learning

Investigation for problem solving

Aim at concept acquisition and process skills

Aim at process skills and concept application

Conducted before concept learning

Conducted after concept learning

More teacher directed in setting problem and hypothesis

More student directed in setting problem and hypothesis

Suggestions for better investigation

• Connect investigation with concept learning

Connect investigation with everyday life and problem solving

rice

Ribena

Glucose-phosphate

Starch synthase

Starch

Find some new, interesting experiments

Make the investigation more challenging:

• set own questions and hypothesis, • quantitative measures, • multiple variables • self prepared materials and choice of

equipment • More complex design

Measuring catalase activity

Different ways of design

Concept learning/application • How is catalase activity affected by

T/substrate conc..? Problem solving • How does catalase activity change during

germination? • How does water shortage/cold shock affect

the catalase activity of seedlings? • Compare the catalase activity of banana,

broccoli and carrot

Skin sensitivity to pain and touch

• Touch each cell with a blunt point • Touch each cell with a sharp point

1 cm

Ask students to set questions and hypothesis

Does skin sensitivity to pain and touch • differ between boys and girls? • differ at different parts of the body? • diminish with repeated stimuli? • diminish with cooling?

Learn ethics in science

• BRIEFING / CONSENT SHEET

Heart rate of Daphnia How T/chemicals affect the heart rate of Daphnia?

•Bring life back to bio lab •Respect life

Nuffield Practical Biology

http://www.nuffieldfoundation.org/practical-biology