OBJECTIVE: STUDENTS WILL BE ABLE TO DESCRIBE THE PHYSIOLOGY OF FINGERPRINTS. Do Now 1. 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 twins 3. 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 different directions  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

Exercise White Balloon Moist wipes Ink your thumb from nail edge to nail edge ¼ 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 tie Observe 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 finger Some may have 3 matches some may have no matches For the ones that match, circle or highlight the figures of the print that appear the same example

Exit Ticket 1. 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?