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Explain how forensic scientists are able to use DNA analysis to identify individuals. a. Comparison of DNA from a known source or individual with analysis of the sequence of an unknown sample of DNA allows scientists to find out if both of them are similar or not. b. DNA from the unknown sample is sequenced and analyzed. The result of the analysis is then matched with any random population. The matching individual then helps in forensics. c. Comparison of DNA from a known source or individual with analysis of the sequence of bases in strands of an unknown sample of RNA allows scientists to find out if both of them are similar or not. d. Comparison of DNA from a known source or individual with analysis of the sugars and phosphates in strands of an unknown sample of DNA allows scientists to find out if both of them are similar or not.

Step by step solution

01

Understanding DNA Analysis

Forensic scientists use DNA analysis to identify individuals by comparing DNA samples. DNA, which carries the genetic information in living organisms, is unique to each individual.

02

Comparison of DNA Samples

DNA from a known source (such as a suspect) is compared with DNA from an unknown sample (such as evidence from a crime scene). This comparison is used to determine if the DNA sequences are similar.

03

Analyzing the DNA Sequence

Scientists analyze the sequence of bases in the strands of DNA. Bases are the chemical units that make up the DNA strand, and their sequence determines genetic identity.

04

Matching Specific Samples

DNA from the unknown sample is sequenced and analyzed. The result is then compared to known profiles in DNA databases to find a match. This helps identify individuals linked to the sample.

05

Eliminating Incorrect Options

Review the provided options:a) Comparison of DNA sequences from known and unknown sources is correct.b) The matching with any random population is not a reliable method.c) Comparing RNA sequences is not a standard forensic method.d) Comparing sugars and phosphates does not provide individual genetic information.Therefore, the correct answer is option 'a'.

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

DNA sequencing

DNA sequencing is a powerful tool used in forensic science to identify individuals uniquely. The process involves determining the exact order of the nucleotides in a DNA molecule. These nucleotides are represented by the letters A (adenine), T (thymine), C (cytosine), and G (guanine). The sequence of these letters forms the genetic blueprint of an individual.
For forensic DNA analysis, scientists begin by extracting DNA from a crime scene sample. Then, they use specialized techniques to sequence the DNA. This sequence is essentially like a genetic fingerprint, making it possible to compare it with other DNA samples.
For example, if DNA is found at a crime scene, it can be sequenced and compared to the DNA of a suspect. If the sequences match, it suggests that the DNA at the crime scene and the suspect's DNA came from the same person.

criminal identification

DNA analysis plays a critical role in criminal identification. This process involves comparing DNA from known sources (like a suspect) with DNA from unknown crime scene samples. This comparison checks for matching sequences to help place a suspect at the crime scene or rule them out.
When forensic scientists analyze DNA, they look for specific regions of the DNA strand known as STRs (Short Tandem Repeats). STRs are highly variable among individuals, making them perfect for identification.
Here's how it works:

• Collect DNA samples from crime scenes and suspects.
• Extract and purify the DNA.
• Use PCR (Polymerase Chain Reaction) to amplify the DNA.
• Sequence the DNA and compare STR regions.

This process helps to either confirm or exclude a suspect's involvement in a crime.

forensic DNA comparison

Forensic DNA comparison is the key technique used to determine if two DNA samples match. Common steps in this process include extracting DNA, sequencing it, and comparing the sequences. Here's a more detailed look at each step involved:

• DNA extraction: This is the process of isolating DNA from cells obtained from a sample.
• DNA amplification: In this step, small quantities of DNA are copied many times to produce enough DNA for analysis, often using a technique called PCR.
• DNA sequencing: The DNA's nucleotide sequence is determined using various sequencing technologies.
• DNA comparison: The sequences from the crime scene and the suspect are compared. STR regions are particularly useful because their variation between individuals makes the comparison highly reliable.

If the DNA sequences match, it indicates a high probability that both samples originated from the same individual. However, if the sequences don't match, it suggests that the samples came from different individuals.
Overall, forensic DNA comparison is a cornerstone of modern forensic science and has revolutionized criminal investigations by providing strong genetic evidence either supporting or refuting connections to the crime scene.