Fiber to Fabric Online Quiz

Fibers are considered trace evidence because they are small, easily transferred, and often left behind at crime scenes. They are not direct evidence, which would be something like a confession or video footage.

Burn test is destructive because it consumes the fiber sample during testing. Microscopy and spectroscopy allow examination without destroying evidence, making them non-destructive alternatives.

Twill weave is characterized by a diagonal pattern, which allows for a higher thread count and greater durability compared to plain or satin weaves. It is commonly used in heavy-duty fabrics like denim.

Secondary transfer occurs when evidence is moved from an original source to a second location, and then to a third. In this case, the fiber moves from the car to the suspect, then to the victim.

Wool is an animal fiber, and under a microscope, it typically shows overlapping surface scales. Other options describe characteristics of synthetic or plant-based fibers.

Cotton fibers exhibit various morphological characteristics under a microscope, including a twisted, ribbon-like appearance (often described as a flat hose) and a hollow core (lumen). Frayed roots are also common in harvested cotton.

Fibers are excellent trace evidence because they are easily transferred, often overlooked by perpetrators, and can be collected and stored for analysis. All these factors contribute to their forensic value.

Wool is a natural protein fiber obtained from the fleece of sheep and other animals. It is not synthetic or derived from seeds or cocoons.

Cotton is a soft, fluffy staple fiber that grows in a boll, or protective case, around the seeds of the cotton plant. It is a classic example of a seed fiber.

Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae, such as silkworms, to form cocoons.

Natural fibers are generally less durable than synthetic fibers and are susceptible to biological degradation by microorganisms like mold and bacteria. Option B correctly identifies both of these common disadvantages.

A plain weave is the simplest and most common weave pattern, where the warp and weft threads cross over each other in a simple one-over, one-under pattern, resembling a checkerboard.

Stem fibers (like flax or hemp) are natural plant fibers. Polyester, nylon, and acrylic are all synthetic fibers created through chemical processes.

Polyester is a synthetic polymer fiber. Animal fibers, seed fibers, and plant fibers are all categories of natural fibers.

When the amount of evidence is very limited, forensic scientists prioritize non-destructive testing to preserve the sample for further analysis or court presentation. Destructive tests are avoided when the sample cannot be replaced.

Forensic scientists focus on physical and chemical properties of fibers to link them to a source. The brand name of a garment is not a standard forensic characteristic, as many brands use the same fibers.

At a crime scene, fibers that are unusual or unexpected are the most significant because they may indicate the presence of a suspect or victim who does not belong there. Expected fibers are often dismissed as background noise.

Fiber evidence can originate from a wide variety of household and industrial sources, including carpets, clothing, linens, furniture, insulation, and rope. All listed items are common sources.

A textile is a flexible, flat material made by weaving, knitting, or felting yarns or threads. Monomer and crystalline are chemical/structural terms, and direct evidence is a legal term.

Natural fibers are those that occur in nature and are derived from animal, plant, or mineral sources. Synthetic fibers are man-made, and monomers/polymers are chemical building blocks.

Synthetic fibers are man-made through chemical synthesis, typically derived from petroleum-based products. Natural fibers come from plants or animals, while monomers and polymers refer to the chemical structure rather than the origin of the fiber.

Yarn is the result of spinning individual fibers together to create a continuous strand suitable for weaving or knitting. Weaving is the process of interlacing these yarns, not the result of spinning fibers.

Secondary transfer occurs when evidence is transferred from an initial source to a victim, and then from the victim to a suspect. Direct transfer is the immediate movement from source to suspect.

Direct transfer refers to the immediate movement of evidence from a source to a victim or suspect. Secondary transfer involves an intermediary step.

Crystalline structures are characterized by an orderly, repeating arrangement of molecules, which contributes to strength. Amorphous structures lack this ordered arrangement.

A weave pattern describes the specific way that warp and weft threads are interlaced. The other options are not standard textile terminology for this process.

A polymer is a large molecule composed of many repeating subunits called monomers. Monomers are the individual units, not the long chain itself.

A monomer is the single, smallest repeating unit that can join together to form a polymer. Polymers are the resulting long chains.

Amorphous materials lack a defined, repeating crystalline structure, resulting in a disordered arrangement of molecules. Crystalline materials are the opposite.

Infrared spectroscopy measures the absorption or reflection of infrared light by a material, providing a unique chemical fingerprint. It is a standard method for identifying fiber composition.

Polarizing light microscopy uses filters to examine the optical properties of fibers, such as birefringence. This helps identify the crystalline structure of the fiber.

In weaving, the weft threads are the crosswise threads that are passed over and under the warp threads. Warp threads run lengthwise.

Warp threads are the lengthwise threads held in tension on the loom. Weft threads are the crosswise threads.