OBJECTIVE: STUDENTS WILL BE ABLE TO DESCRIBE THE PHYSIOLOGY OF FINGERPRINTS.

Do Now1. What is your predicted grade for the test now that you took it?2. T/F: a fingerprint is an individual trait for everyone except identical twins3. What does this graph tell us about fingerprint patterns?

Announcement Quiz 4 make ups this week Extra credit: hand sanitizer, paper

towels, tissue, napkins, Band-Aids and hand soap (especially for this unit)

Notebook check on Thursday New exit ticket style Quiz on Tuesday Gloves on Friday and Monday

Exit Ticket Point of exit ticket Graded everyday 4/5 per week Still part of notebook grade Track your grade Purpose

Fingerprints Look at your fingers There are raised portions on your hands and

toes whose function is to help with grip These raised portions are called friction ridges

CFU: Raised portions used for gripping

Print When these ridges press against things

they leave something know as a fingerprint

The print left behind consist of natural secretions from the sweat glands Includes water, oil, and salt

and dirt from everyday activity

CFU:T/F: A fingerprint is made when your

ridges press against something. This is related to the Locard exchange principle.

Development Start to form between 10th-16th week

of development Basal layer- layer in the skin where skin

cells are produced

What Happens? In the fetus, the basal layer grows faster than the epidermis on the outside The layers collaps and folds in differentdirections Cannot be altered or destroyed permanently because the outer layer protects it

Turn and Talk: When are ridges formed and how do ridges form?

Loops, whorls, and arches Fingerprint characteristics are named for

their appearance…called patterns Arches – 5%- enter one side of the

fingerprint, rise in the middle, exit the other side of the fingerprint

Whorls – 30%- looks like a bulls eye (circles)

Loops - 65% - enter from one side and exit on the same side

ExerciseWhite BalloonMoist wipes

Ink your thumb from nail edge to nail edge¼ way from the top, 2/3 way from the bottom Roll your thumb over the balloon from nail edge to

nail edge Inflate the balloon half way, do not tieObserve your finger print. Is it loop, whorl, or arch?Observe a classmates

Bertillonage Alphonse Bertillon

Developed the first organized system of identifying individuals He said that the odds of two people having the

same bertillonage measurements were 286 million to one

Distinguished by Measurements of key features

DIAMETER OF HEAD, WIDTH OF THE ARMS OUTSTRETCHED

CFU: T/F: The bertillonage system identified

people using the measurement of key features

Fingerprint Matching activity Using the following sheet in front of you:From the impression match the ones that

are made by the same fingerSome may have 3 matches some may

have no matchesFor the ones that match, circle or highlight

the figures of the print that appear the same

example

Exit Ticket1. Raised portions on your hands that allow for

gripping:a. Fingerprint b. Whorls c. Friction

Ridges

2. Define basal layer.

3. If 65% of fingerprints have loops, how are fingerprints considered individual evidence?