Forensic Science: Hair Morphology and Evidence
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Questions and Answers

What method is used to identify a toxicant through body fluids or excrement?

  • DNA extraction
  • Toxicological analysis (correct)
  • Chemical synthesis
  • Chromatography

Which of the following is NOT a typical method for toxicant identification?

  • Analyzing stomach content
  • Measuring for length (correct)
  • Excrement analysis
  • Skin biopsies

Which process would involve examining DNA in relation to toxicant identification?

  • Genomic sequencing (correct)
  • Analyzing inherited traits
  • Determining toxic exposure effects
  • Extensive chemical treatment

What is the main goal of chemically treating samples in toxicology?

<p>To isolate and identify toxic constituents (C)</p> Signup and view all the answers

What type of analysis can be performed to identify toxicants using liquid samples?

<p>Spectroscopic analysis (C)</p> Signup and view all the answers

What is defined as anything that can produce an adverse biological effect?

<p>Agent (D)</p> Signup and view all the answers

Which of the following is NOT a form that an adverse biological effect can take?

<p>Mechanical (B)</p> Signup and view all the answers

Which type of test is included in presumptive laboratory tests?

<p>Color tests (D)</p> Signup and view all the answers

Which of these is an example of a chemical that can produce an adverse biological effect?

<p>Cyanide (C)</p> Signup and view all the answers

What is one of the methods mentioned for presumptive testing?

<p>Microcrystalline tests (B)</p> Signup and view all the answers

What type of adverse biological effect is radiation classified under?

<p>Physical (D)</p> Signup and view all the answers

Which of the following is NOT a presumptive test mentioned?

<p>Gas chromatography (B)</p> Signup and view all the answers

Which of the following is an example of a biological agent causing adverse effects?

<p>Snake venom (B)</p> Signup and view all the answers

What is the primary purpose of presumptive laboratory tests?

<p>To suggest possible substances or conditions (B)</p> Signup and view all the answers

Which statement is true regarding the tests mentioned?

<p>Color tests and microcrystalline tests are qualitative (A)</p> Signup and view all the answers

What is characterized by long periods of time, such as weeks, months, or years?

<p>Chronic exposure (B)</p> Signup and view all the answers

Which type of exposure is considered short-term?

<p>Acute exposure (A)</p> Signup and view all the answers

Which of the following best describes chronic exposure?

<p>Involves long-duration exposure (D)</p> Signup and view all the answers

Acute exposure is to be understood as:

<p>Short-term exposure to harmful substances (A)</p> Signup and view all the answers

Which option does NOT represent a type of exposure related to time duration?

<p>Accelerated exposure (A)</p> Signup and view all the answers

What instruments are mentioned for identifying components in toxicology?

<p>Mass spectrometers and infrared spectrometers (B)</p> Signup and view all the answers

Which of the following is NOT a function of mass spectrometers?

<p>Measuring temperature changes (D)</p> Signup and view all the answers

What type of spectrometer is used alongside mass spectrometers for identification?

<p>Infrared spectrometer (D)</p> Signup and view all the answers

In toxicology, what role do spectrometers play in analyzing samples?

<p>They identify and analyze chemical components. (C)</p> Signup and view all the answers

Why is the identification of components important in toxicology?

<p>It allows for the selection of treatment modalities. (B)</p> Signup and view all the answers

Microcrystalline tests are a special class of presumptive drug analyses that produce what type of products?

<p>Crystalline products (D)</p> Signup and view all the answers

Which type of drug analysis do microcrystalline tests belong to?

<p>Presumptive analysis (C)</p> Signup and view all the answers

What is a key characteristic of the products produced by microcrystalline tests?

<p>They form visible crystals (D)</p> Signup and view all the answers

Which of the following best describes the nature of microcrystalline tests?

<p>They are qualitative in nature (D)</p> Signup and view all the answers

Microcrystalline tests are primarily used for which purpose in drug analysis?

<p>To infer the presence of drugs (D)</p> Signup and view all the answers

Flashcards

Chronic exposure

Exposure to something over a long period, such as weeks, months, or years.

Acute exposure

Exposure to something for a short period.

Long-term exposure

Exposure to something for a significant duration like weeks or years.

Short-term exposure

Brief exposure to something.

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Time periods

Duration of events like weeks or months, used to describe exposure.

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Toxicant identification

Finding the harmful substance by examining body fluids, stomach, waste, or skin.

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Body fluid analysis

Examining body fluids to identify a toxicant.

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Stomach content analysis

Studying the contents of a stomach to identify ingested toxins.

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Excrement analysis

Analyzing waste to discover toxins.

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Skin analysis

Studying skin to discover toxins.

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Toxicant

Any substance that can harm a living organism. It can be chemical, physical, or biological.

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Chemical toxicant

A substance like cyanide that can cause harm through its chemical properties.

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Physical toxicant

A substance that harms through its physical properties, like radiation.

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Biological toxicant

A substance from a living organism that causes harm, like snake venom.

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What are the types of toxicants?

Toxicants can be chemical, physical, or biological. Chemical toxicants are poisonous like cyanide, physical toxicants harm through energy like radiation, and biological toxicants come from living organisms like snake venom.

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Presumptive Tests

Initial laboratory tests that provide a quick, preliminary indication of a substance's presence, but aren't conclusive.

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Color Tests

These tests use color changes to suggest the presence of a substance, based on chemical reactions.

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Microcrystalline Tests

Tests that examine the shape and structure of crystals formed from the substance being tested.

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What are presumptive tests used for?

They are used to quickly screen for the presence of a substance, providing initial evidence that can guide further testing.

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Why are presumptive tests not conclusive?

These tests are sensitive to other substances and can give false positives, so they are not definitive proof.

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Presumptive Drug Analysis

An initial test to determine if a substance is likely a drug, but not conclusive.

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Crystals

Solid materials with a specific, repeating arrangement of atoms or molecules.

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Unique Crystals

Crystals with specific shapes and sizes that identify a particular drug.

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Identify Drug

To determine the specific type of drug present in a sample.

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Component identification

Using instruments like mass spectrometers or infrared spectrometers to determine the specific substances present in a sample.

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Mass Spectrometer (MS)

A scientific instrument that measures the mass-to-charge ratio of ions, helping to identify the different components of a sample.

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Infrared Spectrometer (IR)

An instrument used to identify molecules in a sample by analyzing how they absorb and emit infrared radiation.

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Infrared radiation

A type of electromagnetic radiation that can be absorbed or emitted by molecules.

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What is the role of infrared spectroscopy in component identification?

Infrared spectroscopy helps determine the specific molecules present in a sample by analyzing how they absorb and emit infrared radiation. This analysis provides a unique molecular 'fingerprint' for each component.

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Study Notes

Hair Morphology

  • The basic components of hair are keratin (a strong protein resistant to decay) and melanin (a pigment).
  • Keratin forms stable fibrils.

Hair Layers

  • Hair has three layers: cuticle, cortex, and medulla.
  • The outer layer is the cuticle.
  • The cortex is the middle layer.
  • The inner layer is the medulla.

Hair Collection Evidence

  • Hair and fiber evidence is collected from carpets, bedding, etc.
  • It should be packaged in paper packets.
  • Methods for collection include using hands, powder, hairbrushes, and filtered vacuum cleaners.
  • Other tools may include tweezers and scissors, sticky tape, and lint rollers.

Hair Identification and Comparison

  • Properties like length, color, diameter, presence/absence of medulla, distribution, shape and pigment intensity in the cortex, and whether the hair is dyed, bleached or natural are considered in hair identification and comparison.
  • Forensic scientists can determine species, race, and origin of a hair.
  • This is done through microscopic examination and tests including DNA analysis.

Microscopic Hair Examination

  • Microscopic examination of hair can determine if the hair is from an animal or human.

Presumptive and Confirmatory Tests

  • Presumptive tests indicate the possibility of an illegal substance.
  • Confirmatory tests provide a positive identification of the substance.
  • Presumptive tests include color tests, microcrystalline tests, UV, IR, TLC, and microscopic examination.
  • Confirmatory tests separate and identify components using techniques like gas chromatography, capillary electrophoresis, wet chemistry, alongside instruments like mass spectrometers (MS) or infrared spectrometers (IR).
  • Techniques like chromatography can be used with other techniques, such as UV and infrared spectroscopy, during confirmatory analysis.

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Forensic Chapter 9 Quiz Questions PDF

Description

This quiz covers the essential aspects of hair morphology, including the basic components and layers of hair. It also emphasizes methods for collecting hair evidence and the identification techniques used in forensic science. Test your knowledge on the characteristics and collection of hair in criminal investigations.

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