Chapter 4 - Fibers (pages 90-91)

Natural fibers can be harvested from

• plants and animals

• only from plants

• only from animals

• plants, animals, and minerals

The shiny nature of silk can be related to

• its hollow core

• its ability to refract light

• its smooth, round fibers

• mucus secretions from the silkworm

What characteristics of cotton make it a great source of fiber for clothing?

• It is very easy to grow.

• It is resistant to staining.

• The fibers are easily woven and dyed.

• The fibers are extremely long.

Mineral fibers such as asbestos are very durable. These fibers are used in all of the following except

• rope

• shingles

• floor tiles

• brake lines

All of the following are characteristics of synthetic fiber except

• they are formed by combining monomer compounds into polymer molecules

• they are man-made

• they are used in the production of carpet fibers

• they do not contain any natural fibers

A characteristic of natural fibers is that they

• are stronger than synthetic fibers

• will break down when exposed to bright light

• melt at a lower temperature than synthetic fibers

• are affected by microscopic organisms

Which of the following observations are used to help identify a specific fiber?

• smell of the burned fiber

• on contact with the flame, does the fiber coil or melt?

• color and structure of the residue left after the fiber burns

• all of the above

Fibers are an excellent source of trace evidence because

• they are easily transferred from victim to suspect

• they are often overlooked by a suspect

• they can be easily collected and stored

• all of the above

A fiber is collected at a crime scene. When viewed under a compound microscope, what two traits would indicate that the fiber was a human hair and not a piece of fiber obtained from an article of clothing?

• the presence of a cuticle

• a medullary index of 0.33 or less

• a wide diameter

• its ability to dissolve in water

Natural fibers can be harvested from:

• Plants and animals

• Plants only

• Animals only

• Plants, animals, and minerals