Counsel in a trial are arguing that a DNA analysis isn’t proof that a particular person was at the scene of a crime. As a DNA analyst, DeShawn identified one point that clearly matches the DNA sample and the suspect’s DNA. What should DeShawn’s response as an expert witness be?
A.
Agree with the lawyer that one matching point is likely to be a coincidence.
B.
Argue that the DNA, combined with other testimony, makes the suspect likely to have been there.
C.
Argue that even one point of similarity in a DNA profile means the chances of a mistake are one in a billion.
D.
Argue that the suspect is clearly guilty, and the DNA analysis is irrelevant.
Counsel in a trial are arguing that a DNA analysis isn’t proof that a particular person was at the scene of a crime. As a DNA analyst, DeShawn identified one point that clearly matches the DNA sample and the suspect’s DNA. What should DeShawn’s response as an expert witness be?
A.
Agree with the lawyer that one matching point is likely to be a coincidence.
B.
Argue that the DNA, combined with other testimony, makes the suspect likely to have been there.
C.
Argue that even one point of similarity in a DNA profile means the chances of a mistake are one in a billion.
D.
Argue that the suspect is clearly guilty, and the DNA analysis is irrelevant.
C. Argue that even one point of similarity in a DNA profile means the chances of a mistake are one in a billion.
Humans and chimpanzees share about 98.8 percent of the genetic code. This sounds very close—it’s only 1.2 percent different—until what information is remembered to provide perspective?
A.
1.2 percent represents about 100 different base pairs.
B.
Humans and chimpanzees evolved around the same time period.
C.
1.2 percent represents 36 million different base pairs.
D.
We both walk upright and use tools.
C. 1.2 percent represents 36 million different base pairs.
The final stage of polymerase chain reaction, where special enzymes attach to primers and attach complementary bases along the strand to create a new strand of DNA that binds to the original strand, is called what?
A.
annealing
B.
denaturing
C.
extension
D.
hybridization
C. extension
Where is mitochondrial DNA found in relation to the cell?
A.
inside the nucleus
B.
inside the cell, but outside the nucleus
C.
outside the cell
D.
inside the nucleus of buccal cells
B. inside the cell, but outside the nucleus
As an expert witness, DeShawn's response should be B. DeShawn should argue that the DNA, combined with other testimony, makes the suspect likely to have been at the scene of the crime. It is important for DeShawn to present a balanced and objective perspective based on the evidence.
To explain why DeShawn should choose this option, let's break down the reasoning:
1. DNA analysis is a valuable forensic tool, but it is not considered as absolute proof that a particular person was at the scene of the crime. It provides evidence that can support or refute a hypothesis.
2. DeShawn has identified one point in the DNA analysis that clearly matches the DNA sample and the suspect's DNA. While this matching point is significant, it does not necessarily prove that the suspect was at the crime scene. It could be argued that it is possible for this match to be a coincidence, especially if there are other factors to consider.
3. By choosing option B, DeShawn acknowledges the importance of the DNA evidence but also recognizes the need for additional testimonial or circumstantial evidence to strengthen the case against the suspect. Combining the DNA analysis with other relevant evidence can increase the likelihood that the suspect was indeed present at the scene of the crime.
4. It is essential for DeShawn to remain objective and provide an expert opinion based on scientific principles. Therefore, options A, C, and D are not appropriate as they either dismiss the potential for coincidence, make unsupported claims about statistical probabilities, or disregard the relevance of DNA analysis altogether.
In summary, DeShawn's response should be B, arguing that the DNA, combined with other testimony, makes the suspect likely to have been at the scene of the crime.