Final answer:
An alternate light source (ALS) is useful in forensic science for locating bodily fluids, acting as a crime scene search tool, and observing reactions in bloodstains, by using specific ranges of UV light for visualization and analysis.
Step-by-step explanation:
An alternate light source (ALS) has versatile applications in forensic science and can be employed in multiple ways as follows:
- (a) To locate bodily fluids like semen, urine, or saliva by using UV light in the range of 365-415 nm, which can cause these substances to fluoresce and become visible under the specific light conditions.
- (b) Acts as a crime scene search tool by pairing with a broad pass band filter of 430-520 nm, optimizing the visualization of certain forensic evidence.
- (c) To observe the reactions of fluoroscein in bloodstains, which fluoresce under light wavelengths ranging from 455-485 nm.
- (d) All of the above statements are correct uses of an ALS in forensic contexts.
The question involves understanding how UV spectroscopy and fluorescence can be applied in various scientific and practical scenarios. In forensics, specific wavelengths of light, such as UV light, are used to identify and analyze substances that may not be visible under normal light conditions. In the same vein, proteins possess chromophores like tryptophan that absorb UV light, which is a principle utilized in various biochemical applications.