1KIS International School Science 2010 1. The Power of Words Obtain (v) to get (something) Omar obtained the information that he needed from the touristinformation booth. Step 1. Copy the above word into your Vocabulary Book. Step 2. Complete the activity on the back of this p age. CSI: THE FINGERPRINT ANALYSIS Today’s Tasks 1. Power of Words 2. Pre-Lab 3. Lab 4. Post Lab Questions ATL Connections - Communication - Information Literacy - Collaboration AT L ’ s C o m m u n i c a t i o n G r a d e 7 S c i e n c e M i n i C a s e # 4
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BackgroundSkin has two layers. The deeper layer is the dermis which contains sweat glands, oil glands,nerves and blood vessels. The outer layer is the epidermis which is made of several layers ofcells arranged along ridge patterns. Fingerprints are formed during the fourth and fifth month ofpregnancy and remain unchanged for life.
When skin touches a surface sweat and oils are transferred onto it often leaving behind animpression of the ridge pattern. These impressions are called latent fingerprints because theyare not usually visible to the eye.
Thumbprints were used centuries ago to authenticate documents, but fingerprints were firstdescribed in detail in the 1600s and werenʼt used in solving crimes until about 1880. Policenow use sophisticated software to compare fingerprints found at crime scenes to vastdatabases of stored fingerprint records.
On many surfaces, simple powders can be used to find fingerprints which can then be 'lifted'
using sticky tape to preserve them. Not all surfaces are smooth and shiny however, and manymaterials absorb perspiration and oils into them so sophisticated techniques to reveal andrecord fingerprints are often required.
Once the fingerprints are taken and labeled, forensic scientists use a classification system toidentify them. The three basic fingerprints pattern groups are Loop, Whorl, and Arch. Thereare more complex classification systems that divide the groups further (such as plain archesvs. tented arches, or double loops vs. single loops). We will only identify the three majorgroups.
2) What are the three major groups of fingerprint patterns?
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3) What do we call fingerprints on a surface that cannot usually be seen?
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4) Marc has been kidnapped, and is being held hostage. The kidnappers are demanding aransom of 20 million baht. To show they are serious they have sent a finger with the ransomnote!!! Marc only had his fingerprints taken when he was a baby. Can the police use thosefingerprints to verify if the finger is really Marc's? Explain why or why not.