CSI Biological and Trace Evidence 2

Question 1

Which presumptive test for blood produces a blue-green color change in the presence of hemoglobin?

Accepted Answer

Leuco malachite green test

Answer

Kastle-Meyer test

Answer

Luminol test

Answer

TMB test

Question 2

What is the primary reason investigators use an alternate light source (ALS) when searching for biological fluids?

Accepted Answer

To cause biological fluids to fluoresce or absorb light differently

Answer

To sterilize the evidence surface

Answer

To enhance fingerprint ridge detail

Answer

To determine the age of bloodstains

Question 3

A fiber recovered from a victim's clothing is identified as nylon. Which microscopic characteristic best distinguishes nylon from polyester fibers?

Accepted Answer

Birefringence pattern under polarized light

Answer

Trilobal cross-section

Answer

Circular cross-section with no striations

Answer

Surface scales similar to hair cuticle

Question 4

When collecting soil evidence, what is the recommended minimum number of reference samples that should be taken from around a scene?

Accepted Answer

At least four perimeter samples plus a control

Answer

One composite sample

Answer

Two samples from opposite ends

Answer

One sample adjacent to the evidence

Question 5

Which enzyme is most commonly targeted in confirmatory tests for amylase to identify saliva?

Accepted Answer

Alpha-amylase

Answer

Lactate dehydrogenase

Answer

Acid phosphatase

Answer

Prostate-specific antigen

Question 6

A hair root pulled out forcefully with an intact follicular tag is most useful for which type of analysis?

Accepted Answer

Nuclear DNA analysis

Answer

Mitochondrial DNA analysis

Answer

Microspectrophotometry

Answer

Trace element profiling

Question 7

What characteristic of glass fractures helps determine the direction from which a force was applied?

Accepted Answer

Radial and concentric crack patterns with hackle marks on edges

Answer

The color of the glass fragments

Answer

The weight of individual glass fragments

Answer

The refractive index of the glass