Basic Fingerprint Patterns Aim: How are fingerprints classified? Do Now: take a handout HW: Finish Worksheet

Medical Mystery: People w/ No Prints Cheryl Maynard has a rare genetic disorder called DPR, or dermatopathia pigmentosa reticularis, and she's not only missing fingerprints -- she's also missing those unique marks on her toes, in addition to being unable to sweat. The condition is passed down through the female side of the family. People that suffer from DPR can also have extremely thin hair, brittle, ridged nails and mottled skin. DPR is so rare that the Maynards were the only family in the world known to carry the genetic defect. How is this condition possible? The ridges on our fingers and toes start forming in utero at about 11 weeks. However, if certain genes mutate, the body never creates the signals that form the prints -- resulting in the Maynard family condition.

What is a delta?

LOOP Comes in and curves Goes back out same side Enters and Exits on same side 4

Loops Loops must have one delta Delta on left = Ulnar Delta on Right = Radial Ulnar Loop Loop opens toward little finger. Radial Loop Loop opens toward thumb. Delta NOTE: On the left hand, delta would be on the opposite side

ARCH Enter on one side Rises Falls Goes out on the other side 6

Arches Arches are the simplest type of fingerprints. No deltas are present. Tented Arches Sharp rise Spike or “tent” Plain Arch Smooth rise

Ridges rise smoothly in center in a wave-like pattern Plain Arch Ridges rise smoothly in center in a wave-like pattern Plain Arch Tented Arch Ridges in the center thrust upward to give an appearance similar to a tent. Sharp rise Tented Arch 8

WHORL Ridge recurves around 2 deltas Looks like a circle 9

Plain Whorl One ridge makes a complete circle Line between deltas touches or runs through circle

the line between the deltas does not touch the circle Central Pocket Whorl the line between the deltas does not touch the circle

Double Loop Whorl two loops combined into one fingerprint Looks like an “s” 12

Accidental Any pattern that was not yet mentioned Any combination of patterns mentioned Example: loop with a plain whorl

Identify each fingerprint pattern. ? A B Right Hand Left Hand Answer Key: A - Plain Whorl, B – Double Loop Whorl, C – Radial Loop, D – Tented Arch, E – Plain Arch C Right Hand E D Right Hand Left Hand

A - Plain Whorl, B – Double Loop Whorl, C – Radial Loop, D – Tented Arch, E – Plain Arch

It’s time to make some prints! Textbook pg 77-78 Avoid Partial Prints GOOD PRINT Get as much of the top part of your finger as possible!

Directions 1st – Roll the “pad” portion of your thumb over the ink pad from the left side of your thumb to the right. You do not have to push down really hard! 2nd – Roll the “pad” portion of your thumb from the left side of your thumb to the right in the correct box on your paper to make a thumbprint. 3rd – Continue this process to make a fingerprint of all ten fingers on the “My Prints” worksheet. 4th –Use your notes and a magnifying lens to help you figure out what type of pattern is found in each of your fingerprints. Label each one with the pattern’s name.