Unit 3 Trace Evidence & Microscopy – Vocabulary Flashcards

A comprehensive set of vocabulary flashcards covering key terms from Unit 3: Trace Evidence & Microscopy.

Amorphous

Without a defined shape or form; in solids, atoms are arranged randomly rather than in a distinct pattern.

Anagen phase

The initial growth phase during which the hair follicle actively produces hair.

Becke line

A bright halo observed near the border of a particle immersed in a liquid of different refractive index.

Birefringence

The difference between the two indices of refraction exhibited by most crystalline materials.

Bullet-proof (resistant) glass

A laminated and tempered glass composed of two layers for added strength.

Catagen phase

A short transition stage between the anagen and telogen phases of hair growth.

Chemical property

A property that describes the behavior of a substance when it combines with another substance.

Concentric fracture

A circular pattern of cracks that forms around a point of impact in glass.

Condenser

The lens system beneath a microscope stage that collects light and focuses it onto the specimen.

Cortex (hair)

The region of hair located outside the medulla that contains granules of pigment.

Crystalline

Geometrically shaped; fibers composed of polymers packed side-by-side, making them stiff and strong.

Cuticle (hair)

The tough outer covering of a hair composed of overlapping scales.

Density

The ratio of the mass of an object to its volume.

Eyepiece lens

The upper lens of a compound microscope through which the viewer looks.

Fiber

The smallest indivisible unit of a textile; at least 100 times longer than it is wide.

Follicular tag

A translucent piece of tissue surrounding the hair’s shaft near the root; richest source of DNA on hair.

Glass

A hard, transparent, amorphous, brittle solid made by heating silica and other materials.

Hair follicle

The actively growing base of a hair that contains DNA and living cells.

Hair shaft

The part of hair above the follicle; contains mitochondrial DNA.

Intensive property

A property that does not depend on the size of an object.

Keratin

A fibrous protein that makes up the majority of the cortex of hair.

Laminated glass

Two sheets of ordinary glass bonded together with a plastic film.

Lead glass (crystal)

Glass containing lead oxide.

Manufactured fibers

Fibers derived entirely from animal or plant sources (according to lecture notes).

Medulla (hair)

The central core of a hair.

Melanin granules

Particles of pigment found in the cortex of a hair.

Mineral

A naturally occurring, crystalline solid formed over time.

Mineral fiber

A collection of mineral crystals formed into a recognizable pattern.

Mitochondrial DNA

DNA found in mitochondria, inherited maternally; mitochondria supply energy to the cell.

Natural fiber

A fiber produced naturally and harvested from animal, plant, or mineral sources.

Normal line

A line drawn perpendicular to the interface of two different media.

Nuclear DNA

DNA present in the nucleus of a cell, inherited from both parents.

Physical property

A property that describes the behavior of a substance without reference to another substance.

Objective lens

The lower lens of a compound microscope, positioned directly over the specimen.

Radial fracture

A pattern of cracks that move outward from a point of impact in glass.

Refraction

The change in direction of light as it changes speed when moving from one substance to another.

Refractive index

A measure of how light bends as it passes from one substance to another.

Sand

Granules of fine rock particles.

Silicon dioxide (SiO2)

The chemical name for silica, the primary ingredient in glass.

Tempered glass

Glass strengthened by introducing stress through rapid heating and cooling of its surfaces.

Textile

A flexible, flat material made by interlacing yarns or threads.

Weft

A crosswise yarn or thread in a weave.

Yarn

Fibers that have been spun together.