Exam 11: Hairs and Fibers

Which statement is true?

Hair can best be characterized as originating from an animal by examining:

A human head hair is best characterized by:

The cuticle is formed by overlapping scales that always point away from the tip end of each hair.

The portion of the hair containing its scales is:

Collecting ________ full-length hairs from all areas of the scalp normally ensures a representative sampling.

Match the word in Column 1 to its definition in Column 2. Each answer can only be used once. A)Fibers derived from either natural or synthetic polymers B)A transition stage between the anagen and telogen phases of hair growth C)Two or more atoms held together by chemical bonds D)A cellular column running through the center of the hair E)DNA that is present in the nucleus of a cell and that is inherited from both parents F)The scale structure covering the exterior of the hair G)The final growth phase in which hair naturally falls out of the skin H)DNA present in small structures outside the nucleus of a cell.. This form of DNA is inherited maternally (from the mother). I)A substance composed of a large number of atoms that are usually arranged in repeating units J)The main body of the hair shaft K)Fibers derived entirely from animal or plant sources L)The basic unit of structure from which a polymer is constructed M)A molecule with a high molecular mass N)The initial growth phase during which the hair follicle actively produces hair O)A translucent piece of tissue surrounding the hair's shaft near the root that contains the richest source of DNA associated with hair -Telogen phase

In what stage can a hair most readily be removed from the scalp?

What is the rate of human hair growth per month?

The cortex derives its major forensic importance from the fact that it gives hair its color.

Generally, the parallel refractive index of a fiber is ________ the perpendicular refractive index of the same fiber.

What is refraction? How does the refractive index of a medium affect what the viewer observes when looking at the medium?

The ________ is embedded with pigment granules that give hair its color.

Why must questioned hairs and standard/reference hairs being compared come from the same area of the body?

The visible light microspectrophotometer is a convenient tool with which to compare the color of fibers because:

Which race is most likely to have head hair with continuous medullae?

Match the word in Column 1 to its definition in Column 2. Each answer can only be used once. A)Fibers derived from either natural or synthetic polymers B)A transition stage between the anagen and telogen phases of hair growth C)Two or more atoms held together by chemical bonds D)A cellular column running through the center of the hair E)DNA that is present in the nucleus of a cell and that is inherited from both parents F)The scale structure covering the exterior of the hair G)The final growth phase in which hair naturally falls out of the skin H)DNA present in small structures outside the nucleus of a cell.. This form of DNA is inherited maternally (from the mother). I)A substance composed of a large number of atoms that are usually arranged in repeating units J)The main body of the hair shaft K)Fibers derived entirely from animal or plant sources L)The basic unit of structure from which a polymer is constructed M)A molecule with a high molecular mass N)The initial growth phase during which the hair follicle actively produces hair O)A translucent piece of tissue surrounding the hair's shaft near the root that contains the richest source of DNA associated with hair -Macromolecule

Hair is an appendage of the skin that grows out of an organ known as the hair ________.

During a microscopic comparison of two hairs, a trace analyst compares the medullae of the hairs to determine species of origin and, if possible, human origin of the hairs. What is the difference between the medullae of human and animal hairs? Name one exception to this among humans that may help in these determinations.

The entire hair is collected because a hair may show variation in color and other morphological features over its entire length.