Fingerprint Lab

Fingerprints• Fingerprints are an impression of the

lines on the inner surface of the thumb and fingers.

• Patterns are made by tiny ridges on the skin.

• The ridges on our fingertips help us grip objects.

• When we touch an object, the oil and perspiration (sweat) on our skin leaves behind a latent (potential) fingerprint.

Fingerprints• Investigators dust latent fingerprints

with a fine powder to make the patterns visible and then lift the fingerprints with sticky paper.

• Fingerprints are permanent details that are created before you are born.

• No two fingerprints are the same, not even on the same person or on identical twins.

Lab Write Up• Title: Fingerprint Lab

•Problem: Which is the most common type of fingerprint in our class?

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3 Types of FingerprintsWhorls

30-35 % of people

Arches5 % of people

Loops60-65% of

people

ResearchWhat do you know about

fingerprints?

Have you ever checked your fingerprints? Tell me your experience with fingerprints.

HypothesisHypothesis: If… then…because…

If each person finds their fingerprint type, then the _________ (loop whorl, arch) fingerprint will be the most common because__________

UNDERLINE the words IF THEN and BECAUSE in your hypothesis

Materials• 1 piece of scratch paper• 1 pencil• 1 magnifying glass• 1 roll of clear tape

VariablesIndependent Variable (the one

thing you change) – the type of fingerprint

Dependent Variable (the one thing

you measure) – the number of fingerprints

Procedure1. Rub the pencil on the scratch paper until there is a

smudge of graphite the size of your fingertip.2. Select which hand you will take fingerprints from.3. Beginning with your thumb. Rub it on the smudge

until your thumb is covered in graphite.4. Place a small piece of tape over your thumbprint

and press down gently.5. Carefully remove the tape and stick it in the

appropriate square on your data table.6. Repeat the process for the other 4 fingers of your

hand. 7. Look at your fingerprints and identify which type of

fingerprint you have.8. Record the class tallies for each type of fingerprint

and then find the total

Data

Loop

TABLE DATA

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Identify your type of fingerprint

Graph

Type 0

2

4

6

8

10

12

14

Fingerprints

LoopWhorlArch

Type of Finger Print

Nu

mb

er

of

Fin

ger

Pri

nts

After you make your graphAnswer the following

questions using COMPLETE SENTENCES.

1. What percent of your class had arches? Whorls? Loops? Find the percentage by dividing the number of each type of fingerprint by the total number of fingerprints and then multiplying by 100Ex: 5 whorls/20 total fingerprints = .25 .25 x100 = 25%

2. What is the most common type of fingerprint in your class?

3. Was your hypothesis supported? Why or why not?

4. Make a Fingerprint Animal

When you are finshed

Try making some fingerprint

animals

Data

Tally Marks and then write the

total

Loop

/Group Data