forensic test

The rate of hair growth is important to know because it can help determine the last time hair was chemically treated. What is the rate of human hair growth?

1.3 cm per month

Which of the following statements is true about synthetic fibers?

A type of synthetic fiber is the regenerated fiber, which is derived from cellulose and is mostly plant in origin.

Which of the following matches the hair growth stage with the correct description?

Anagen: active growth stage, 80-90% is in this stage

What molecule do all plant fibers share in common?

Cellulose

Many dyes and hair treatments will show signs under certain wavelengths. If the sample contains a particular chemical, it will absorb the wavelength and reemit it at a different wavelength. What technique or tool is used to complete this analysis?

Fluorescence Microscopy

Fill in the following statement with the correct vocabulary: DNA is found in the and is specific to a(n) and will yield evidence.

Mitochondrial (mtDNA); hair shaft; group of people; class

• Fill in the following statement with the correct vocabulary: DNA is found in the and is specific to a(n) and will vield evidence.

Nuclear; follicle; individual; individualized

Which of the following is a disadvantage of manufactured fibers?

They deteriorate faster in bright sunlight.

Which of the following fibers are made out of keratin?

Wool

Which of the following characteristics is found in typical Asain hair?

dark medulla

Which of the following characteristics is found in typical African hair?

densely distributed granules in clumps

There are multiple ways to test fibers without damaging the evidence. Which of the following are NOT ways to analyze the fibers without causing damage?

electron microscopy & fluorescence microscopy

Which of the following CAN NOT be found in hair analysis?

exact time of ingestion

Fiber evidence is collected using *1/1 a variety of methods. Which combination of methods below is INCORRECT?

glue and vacuums

Forensic scientists distinguish several different types of hair on the human body. Which is the complete AND correct list of hair types?

head, eyebrows & eyelashes, beard & mustache, underarm, body, and pubic

Hair cuticles for mammals differ in shape and size. Human cuticles can be described as which of the following?

imbricate

What type of medulla pattern shows the pigment line being broken at regular intervals?

interrupted

Hair viewed for forensic investigations is studied both macroscopically and microscopically. Microscopic characteristics DO NOT include which of the following?

length of the hair shaft

Animal hair and human hair have several differences. Which of the following is not a difference?

medulla types

Fibers can be separated into many different categories. Which of the following is the correct way to classify the fibers?

natural (plant, mineral or animal) or synthetic (polymers & regenerated)

There are five main patterns of medulla that forensic scientists use to identify hair. Which of the following is NOT a type of medulla?

thin

For identification purposes, forensic scientists analyze what to identify yarn?

twist direction

Early collection of fiber evidence in an investigation is critical. Within what time period and what percentage of fibers are lost?

within 24 hours 95% is lost

Although variations can occur, which of the following best describes European hair?

straight or wavy with evenly distributed granules