The Scientific Process in Biology

V.C.E. Biology Unit One2010

Mr Hale

Scientific Process in Biology

• Two Lessons

Scientific Process in Biology

• First Lesson– Observation (e.g. visual, auditory,

anecdotal)– Hypothesis (If … then … statement)– Scientific Language

Scientific Process in Biology

• Second Lesson– Experimental Design

• Variables– Controlled– Independent– Dependent

– Sample Size– Results (data [singular = datum])– Analysis– Discussion– Bibliography

Observation

• Some people press the ‘walk’ button at pedestrian crossings multiple times, other people only press it once. Why, what are the people who press the button more than once trying to achieve?

Hypothesis(If … then … Statement)

“Red Bull™ gives me wings”

Hypothesis(If … then … Statement)

If … independent variable … then … dependent variable … statement

Hypothesis(If … then … Statement)

• “Red Bull™ gives me wings”• Hypothesis: If you drink Red Bull™,

then you will grow wings and fly.

Hypothesis

• If you press the walk button at a pedestrian crossing more than once, then the lights will change to ‘walk’ more quickly.

Biological Observation

Biological Observation

Biological Observation

Biological Observation

Biological Observation

• Population of Cactoblastis cactorum at Bulla on Jacksons Creek (west of Melbourne Airport at Tullamarine)

• Cactoblastis cactorum eggs laid before 22nd December hatch in about ten days.

• Cactoblastis cactorum eggs laid after 22nd December hatch in about four days.

Biological Observation

• Cactoblastis cactorum embryos are able to measure the change in daylight between successive days (minutes) and identify when the amount of daylight is increasing or decreasing. Decreasing daylight results in the embryos increasing their development rate.

Biological Hypothesis

• If Cactoblastis cactorum embryos are able to measure the change in daylight between successive days (minutes) and identify when daylight is decreasing and subsequently increasing their development rate, then Cactoblastis cactorum embryos are able to regulate their own development using decreasing daylight as the stimulus.

Scientific Language

• Science has a very exact structure, format and style

• Uses specialised words and phrases• Procedure– Detailed factual description– Imperatives (e.g. draw a line, heat the

water)– Time markers (e.g. after, until, as soon as)– Past Tense– Third person

Scientific Language

• Genus and species names in italics• Specific units of measure– mL, nm, μm, msec-1 (m/sec), molL-1 (mol/L)

• Scientific notation for numbers– 3.4 x 104, 2.45 x 10-5

• Chemical symbols– H2O, NaCl, C6H12O6

• Harvard Referencing Style

Scientific Language

• Communicate with other scientists• Know exactly what the hypothesis is• Able to reproduce exactly the same

experimental conditions• Know exactly what the controlled,

independent and dependent variables were.