BIO UNIT VII ASSIGNMENT

BIO UNIT VII ASSIGNMENT

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1. After reviewing the DNA evidence presented in Figure 2, which of the three suspects is the likely burgler of Paul’s Pierogi Palace? Explain your answer.

Sample 2. The DNA sample taken from a crime scene is compared with a DNA sample from the suspect and the two DNA profiles are a match. This means that suspect 2 is the likely burgler of Paul’s Pierogi palace.

1. Only DNA for the Terrible Towel found at Paul’s Pierogi Palace could be used in gel electrophoresis and not that from the partially eaten pierogis. Why was this so? What does this mean for crime scene analysis using DNA?

The partially eaten Pierogis were contaminated with bacteria. Bacteria mostly act on the DNA directly, causing damage which may result in errors during replication and hence bacteria can severely damage DNA and cause cell death.

1. You are investigating a crime scene in which only a microscopic amount of DNA was found as potential evidence. Can this tiny amount be used to help solve a crime? Explain your answer.

Yes. By correcting the DNA of the suspects, even very small amounts of DNA can yield enough material for DNA comparison with those of the suspects.

1. After reviewing the DNA evidence presented in Figure 3 for the paternity case, which of the three possible fathers is the biological father? Explain your answer.

Father 1. Man 1 would be the most likely father of the child because if we observe and compare the STRs band and the VNTRs band of the child, father and mother, then we can say that the bands of the child on the particular locus are having a match with mother or the man 1most likely.

1. Eyewitness evidence linked two suspects to a crime. DNA analysis was done to identify which suspect was the perpetrator of the crime. Despite solid DNA evidence, neither suspect was charged because a specific single individual could not be identified as required by law and the case remains unsolved. From what you know about genetics, why was DNA evidence useless to identify a suspect in this case? Explain your answer.

Eyewitness testimony, which relies on the accuracy of human memory, has an enormous impact on the outcome of a trial. Eye witnessing might be contaminated and contaminated forensic evidence of any kind — not just contaminated eyewitness evidence — can lead to a wrongful conviction

1. In-gel electrophoresis, some DNA fragments move faster and farther in the agarose gel than others. Why is this so? Explain your answer.

The DNA molecules have a negative charge because of the phosphate groups in their sugar-phosphate backbone, so they start moving through the matrix of the gel towards the positive pole. When the power is turned on and current is passing through the gel, the gel is said to be running. As the gel runs, shorter pieces of DNA will travel through the pores of the gel matrix faster than longer ones. After the gel has run for a while, the shortest pieces of DNA will be close to the positive end of the gel, while the longest pieces of DNA will remain near the wells. Very short pieces of DNA may have run right off the end of the gel if we left it on for too long.

1. What specific trait makes DNA unique among biological molecules?

Every person depicts their DNA except identical twins who sometimes show similarity and is synthesized in the 3′ to 5′

1. From what you know about the pairing of bases in the DNA molecule, list a complementary base sequence to this example, where A = adenine, T = thymine, G = guanine and C = cytosine: GCATG.

Cytosine can form three hydrogen bonds with guanine, and adenine can form two hydrogen bonds with thymine. Or, more simply, C bonds with G and A bonds with T.

1. DNA does not make proteins but instead directs the process. How does this occur?

Genes contain information that is needed to make proteins. However, the genes direct the process during the process of transcription, translation of an information process. The information stored in a gene’s DNA is transferred to a similar molecule called RNA (ribonucleic acid) in the cell nucleus. The second step in getting from a gene to a protein takes place in the cytoplasm. A type of RNA called transfer RNA (tRNA) assembles the protein, one amino acid at a time. Protein assembly continues until the ribosome encounters a “stop” codon.

1. Which DNA fragment move faster and farther during gel electrophoresis – one of 500 bp or one of 200 bp? Explain your answer.

The DNA with 200bp will move faster than the DNA with 500bp. As the gel runs, shorter pieces of DNA will travel through the pores of the gel matrix faster than longer ones. After the gel has run for a while, the shortest pieces of DNA will be close to the positive end of the gel, while the longest pieces of DNA will remain near the wells