Fingerprints, a Classification System

Target Curriculum: Science

Target Grade: 6 - 8

SOLs: MAT.7.20   MAT.7.21   SCI.LS.1   SCI.LS.5  
Time: 2-3 1 hour periods

Objective:
Students will:
1. Observe differences and similarities in fingerprints
2. Develop a system to classify prints into similar groups

Purpose:
This lesson allows students to discover the usefulness of grouping things according to similarities and differences. It is a good introduction to classification systems in Life science.

Materials:
pencils, sharpener, transparent tape, index cards, white paper (copy paper) hand magnifiers (not essential)

Procedure:
1.Have students trace an outline of their hand onto a plain piece of white copy paper
2. Rub pencil onto an index card making a graphite pad for taking prints
3. inform students that they will be making a print of their finger pads, not finger tips
4. press/roll finger firmly onto the penciled area
5. stick a short piece of tape to the finger pad and press it into place. carefully remove the tape and press it onto the hand outline in the proper location. The student should now have a good print of their finger pad.
6. Continue with each finger until each student has a complete record of one hand (students should use their dominant hand)
7. Have groups of students compare prints for similarities and differences. What kinds of patterns do they see. Are all the prints on one hand the same? Help them give names to the different patterns. Can the students come up with two or three descriptive names?
8. Give students handout found at www.aimsedul.org/activities/gimmefive/gimme3html
This shows 3 basic fingerprint patterns; loops, arches and whorls. A more detailed handout can be found at:
www.eecs.umich.edu/mathscience/fun
9. Lead a student discussion concerning why it would be useful to law enforcement agencies to have a way to group prints.
10. Inform students that this is what scientist do when they classify living things.

Observations:
1.Classification systems allow us to organize and make sense of our world.

Conclusions:
classification systems provide a useful tool for organizing large numbers of things, whether they are living things, or the clothes in your closet

Extension:

1.create a database of prints from many people
2. create bar graps showing distribution of patterns
3. using your database predict the probability of different patterns
4. create a crime scene using a print from someone in your group. See how fast students can identify the print without using their database. Then see how fast they can identify another print using their database

Class Discussion Questions:
Why is it useful to group similar things together?
Do you group anything at home? clothes, CD's or tapes, movies...Why is it useful
Do you think there is a right and wrong way to classify things or is it simply useful or not useful?

Cautions and Concerns:
Provide an opportunity for students to wash their hands after making prints to avoid making clothes and furniture dirty.