SCIENTIFIC METHODSCIENTIFIC METHODIN ACTION!IN ACTION!

Mrs. SprenkleMrs. Sprenkle

BiologyBiology

Steps of the Scientific Steps of the Scientific MethodMethod

**MAKE OBSERVATIONS!!!**MAKE OBSERVATIONS!!! AAsk a QUESTIONsk a QUESTION FForm a HYPOTHESISorm a HYPOTHESIS TTEST the hypothesisEST the hypothesis AANALYZE dataNALYZE data DDRAW conclusionsRAW conclusions CCOMMUNICATE resultsOMMUNICATE results

Problem 1: Problem 1: YOU ARE A MECHANICYOU ARE A MECHANIC

David's car will not start. Use the David's car will not start. Use the scientific method find out why it scientific method find out why it will not start.will not start.

ASK A QUESTION:ASK A QUESTION:Why won’t David’s car start? Why won’t David’s car start?

OBSERVATIONS!OBSERVATIONS!(to help make an “educated guess”)(to help make an “educated guess”)

1.1. The gas gauge is on empty!The gas gauge is on empty!Make a hypothesis!Make a hypothesis!How would you test this?How would you test this?

RESULTS: You pour 2 gallons of gas in David’s car. It RESULTS: You pour 2 gallons of gas in David’s car. It still will not start.still will not start.

What do you conclude about the gas hypothesis?What do you conclude about the gas hypothesis?

OBSERVATIONS!OBSERVATIONS!2. The lights come on, but they are not be as 2. The lights come on, but they are not be as

bright as usual.bright as usual.Make a hypothesis!Make a hypothesis!How would you test this?How would you test this?

1.) You connect a battery charger to 1.) You connect a battery charger to David’s car battery. The battery will not David’s car battery. The battery will not charge. You take the battery to a garage charge. You take the battery to a garage where it is diagnosed as a dead battery. where it is diagnosed as a dead battery. 2.) You install a new battery. The car 2.) You install a new battery. The car starts.starts.

What conclusion can you draw about the What conclusion can you draw about the hypothesis?hypothesis?

Who do you communicate the results to?Who do you communicate the results to?

Problem 2:Problem 2:YOU ARE A DOCTORYOU ARE A DOCTOR The Clampets are on a bear safari in the The Clampets are on a bear safari in the

pacific northwest. They have killed 5 bears. pacific northwest. They have killed 5 bears. That evening they ate bear meat to That evening they ate bear meat to

celebrate their successful hunt. They used celebrate their successful hunt. They used water from a nearby stream to make their water from a nearby stream to make their coffee. They return home to brag about the coffee. They return home to brag about the bears they killed.bears they killed.

A few weeks later several of the Clampets A few weeks later several of the Clampets became sick. They ached all over. At first became sick. They ached all over. At first they passed it off as the flu. But the they passed it off as the flu. But the symptoms did not go away. symptoms did not go away.

Use the scientific method to determine Use the scientific method to determine what is making the Clampets sick.what is making the Clampets sick.

Background InformationBackground Information(to help make an “educated guess”)(to help make an “educated guess”)

1.1. Mountain streams sometime harbor a Mountain streams sometime harbor a parasite called Giardia. Many backpackers parasite called Giardia. Many backpackers have become ill with this parasite after have become ill with this parasite after drinking spring water.drinking spring water.

2. Bears, pigs and other animals are 2. Bears, pigs and other animals are sometimes infected with the trichina sometimes infected with the trichina worm. People who eat rare meat that is worm. People who eat rare meat that is infected with this worm can get trichinosis. infected with this worm can get trichinosis.

HYPOTHESIS 1HYPOTHESIS 1 If the Clampets used stream water to If the Clampets used stream water to

make their coffee, then Giardia from make their coffee, then Giardia from the stream water is the cause of their the stream water is the cause of their illness. illness.

The Giardia parasite looks like this The Giardia parasite looks like this under a microscope. This sample was under a microscope. This sample was from a stool smear of a patient from a stool smear of a patient infected with Giardia. infected with Giardia.

Giardia Test ResultsGiardia Test Results This slide represents the results of a This slide represents the results of a

stool Giardia test for all the Clampets. stool Giardia test for all the Clampets.

Is the hypothesis correct?Is the hypothesis correct? Slide w/ giardia

Clampet test slide

Hypothesis 2Hypothesis 2

If the Clampets did not completely If the Clampets did not completely cook their bear meat, then they cook their bear meat, then they contracted trichinosis from one of the contracted trichinosis from one of the infected bears.infected bears.

The trichinosis worm looks like this The trichinosis worm looks like this under a microscope. This sample was under a microscope. This sample was isolated from an animal with isolated from an animal with trichinosis. trichinosis.

Trichinosis Test ResultsTrichinosis Test Results

This slide represents the results of a biopsy This slide represents the results of a biopsy from Jed Clampet. from Jed Clampet.

Draw a Conclusion: is the hypothesis correct?Draw a Conclusion: is the hypothesis correct? Who would you communicate results to?Who would you communicate results to?

Clampet Trichinosis slide

Trichinosis

Further InformationFurther Information Mr. Whitecloud is the spiritual leader Mr. Whitecloud is the spiritual leader

of the few remaining natives that live of the few remaining natives that live in the region where the Clampets and in the region where the Clampets and others go on bear hunting safaris. He others go on bear hunting safaris. He says that the Clampets were cursed says that the Clampets were cursed by a spirit for killing bears on sacred by a spirit for killing bears on sacred land. Whitecloud rejects the land. Whitecloud rejects the trichinosis hypothesis.trichinosis hypothesis.

Is it possible to test Whitecloud’s Is it possible to test Whitecloud’s explanation?explanation?

Problem 3:Problem 3:YOU ARE A CSIYOU ARE A CSI

Sally Smith was found murdered Sally Smith was found murdered in the middle of the road. Her car in the middle of the road. Her car was carjacked. Two days later was carjacked. Two days later the car was found. No one saw the car was found. No one saw the murder happen. Can the the murder happen. Can the scientific method be used to scientific method be used to solve this crime?solve this crime?

OBSERVATION 1OBSERVATION 1

The police made many The police made many observations about this case. observations about this case. One important observation was One important observation was fingerprints on Sally's car.fingerprints on Sally's car.

Observation 2Observation 2 The police received tips about three possible The police received tips about three possible

suspects in this case. Fingerprints were taken from suspects in this case. Fingerprints were taken from each.each.

What hypothesis could you develop about this crime What hypothesis could you develop about this crime based on the evidence (observations)?based on the evidence (observations)?

Felix:

A convicted drug dealer

Jesse: Suspect in killing two

women

James:

Suspect in the murder of a

doctor

Hypothesis: If the fingerprint Hypothesis: If the fingerprint matches one of the suspects matches one of the suspects fingerprints, then that suspect fingerprints, then that suspect may be Sally’s killer. may be Sally’s killer.

We can TEST our hypothesis by We can TEST our hypothesis by comparing the fingerprints comparing the fingerprints

below.below.

Print from Print from Print from Print from

CAR FELIX JESSE JAMES

Draw a conclusion?

Who do you communicate the results too?

Jesse confessed to the murder Jesse confessed to the murder when he was confronted with when he was confronted with

scientific evidence for this scientific evidence for this case.case.

So, let’s try some of our own work So, let’s try some of our own work with the SCIENTIFIC METHOD!!!with the SCIENTIFIC METHOD!!!

http://www.occc.edu/trandall/biologylabs/Documents/Scientific%20Method/Scientific_method.htm