study guide

Question 1

what are fibers?

Answer 1

the smallest individual unit of a textile; it must be 100 times longer than wide

Question 2

What is trace evidence?

Answer 2

small but measurable amounts of physical or biological material found at a crime scene.

Question 3

What is direct transfer?

Answer 3

the passing of evidence, such as a fiber, from victim to suspect or vice versa

Question 4

what is secondary transfer?

Answer 4

the transfer of evidence, such as a fiber, from a source (for example, a carpet) to a person (suspect), and then to another person (victim)

Question 5

how are fibers collected?

Answer 5

Fiber evidence can be collected using forceps, tape, vacuums, and even lint rollers

Question 6

What can fiber evidence reveal

Answer 6

1. type of fiber
2. fabric color
3. numbers of fabric found
4. where the fabric was found

Question 7

what is a textile?

Answer 7

A flexible, flat material made from interlacing yarns (or threads).

Question 8

what are the 3 sources of animal fiber?

Answer 8

hair, fur, and webbing

Question 9

Why is animal hair considered a good piece of trace evidence?

Answer 9

because it sheds easier

Question 10

what polymer makes up all plant fibers?

Answer 10

cellulose

Question 11

what is monomer?

Answer 11

small, repeating molecules that can link to form polymers

Question 12

what is polymer?

Answer 12

a substance composed of long chains of repeating molecules.

Question 13

What are the 4 sources of plant fiber?

Answer 13

seeds, fruits, stems, leaves

Question 14

what is the difference between amorphous and crystanllie?

Answer 14

Amorphous is without a defined shape; fibers are composed of loose arrangement of polymer that are soft, elastic and absorbing. Crystalline is geometrically shaped; fibers are composed of polymers packed side by side, which makes them stiff and strong.

Question 15

what are 2 kinds of mineral fiber?

Answer 15

fiberglass and asbestos

Question 16

what are two types of synthetic fibers?

Answer 16

Regenerated fibers and synthetic polymer fiber

Question 17

what are the five types of synthetic fibers?

Answer 17

Rayon, nylon, acrylic polyester, and olefins

Question 18

how do natural and synthetic fibers differ under the microscope?

Answer 18

Natural fibers have an imperfect look and have varying diameter sizes. Synthetic fibers look uniform and have the same diameter sizes, depending on the synthetic fiber.

Question 19

what happens to fiber if they are too short in their natural state to make textiles?

Answer 19

they are spun into yarn

Question 20

how are fibers woven into fabrics or textiles?

Answer 20

threads are arranged side by side (the warp ) and more threads ( weft) are given back and forth and crosswise through the warp

Question 21

what is synthetic fiber?

Answer 21

a fabric made from manufactured substances, such as plastic.

Question 22

what are 3 sources of natural fiber?

Answer 22

Animals, Plants, and minerals