The Task
On February 14, 2019, 7:36 pm, Carelton Comet was found dead with a knife in the back of his neck. A death note was found on the scene. There were 5 people present at the time of his murder: Theresa Terra, Fred Flimmer, Sam Sophomore, Glen Glee, and Nancy Normal. Each of these suspects has been influenced by Carelton Comet in some way, and one of them killed him. My group, James, Vanessa, Jada, and I, had to investigate this murder and find and arrest the suspect. This project was very in depth and very fun.
The Presentation
There was one death, five suspects, and a lot of evidence. We spent roughly a month on the project. After a lot of investigation and consideration, my group decided to charge Nancy Normal with the first degree murder of Carelton Comet. We charged her because her fingerprint, pen, blood type, chromosomes, and DNA matched with the ones found on the scene. She also had a solid motive. This is all present in the presentation.
DNA Structure
DNA's structure is very complicated and specific. DNA, or deoxyribonucleic acid, is built off of a sugar phosphate backbone. This backbone is made from deoxyribose, a sugar, and a phosphate. This backbone creates the structure of DNA. Nucleotides are built off this backbone. There are 4 types of nucleotides found in DNA: adenine, or A, thymine, or T, cytosine, or C, and guanine, or G. Adenine always connects to thymine and cytosine always connects to guanine. The nucleotides are held together by hydrogen bonds. DNA is also in a double helix form. This connects with the project because every suspect has their own unique DNA sequence.
DNA Replication
DNA is constantly replicated in the body. DNA replicates itself because extra DNA is needed for cell division. The first step of DNA replication is when it is unzipped by an enzyme called helicase. The helicase breaks the hydrogen bonds between nucleotides and the replication fork is created. There is a leading strand and a lagging strand. Whether a DNA strand is leading or lagging is determined by its directionality. DNA is either in a 3 prime to 5 prime direction or a 5 prime to 3 prime direction. The leading strand is 5' to 3', while the lagging strand is 3' to 5'. From here, replication is similar and different for each of these strands.
Both strands are replicated by using DNA polymerase, which is the enzyme that adds the nucleotides. However, polymerase needs something to help direct and start off the replication process. Primase is an enzyme that places down a primer, which is necessary for replication. On the leading strand, when the primer is placed down, the polymerase is able to go straight through the whole strand and add all the nucleotides. The lagging strand is different, however, because it is in the opposite direction. What happens here is that multiple primers are placed down and polymerase adds some nucleotides to each. These created "fragments" are called Okazaki fragments. Then, an enzyme called ligase glues together these fragments, thus finishing replication on both strands. The replicated DNA is semi-conservative because there's one old and one new strand in each new DNA strand.
This connects to the project because DNA replication sometimes causes mutations, and the different effects of mutations can be seen in each suspect.
Both strands are replicated by using DNA polymerase, which is the enzyme that adds the nucleotides. However, polymerase needs something to help direct and start off the replication process. Primase is an enzyme that places down a primer, which is necessary for replication. On the leading strand, when the primer is placed down, the polymerase is able to go straight through the whole strand and add all the nucleotides. The lagging strand is different, however, because it is in the opposite direction. What happens here is that multiple primers are placed down and polymerase adds some nucleotides to each. These created "fragments" are called Okazaki fragments. Then, an enzyme called ligase glues together these fragments, thus finishing replication on both strands. The replicated DNA is semi-conservative because there's one old and one new strand in each new DNA strand.
This connects to the project because DNA replication sometimes causes mutations, and the different effects of mutations can be seen in each suspect.
How Genes Are Expressed
Genes are strands of nucleotides that code for a certain molecule. Alleles are variations of genes. Genes have a genotype and a phenotype. The genotype is how the gene is expressed at the DNA level. The phenotype is how the gene is expressed at the physical level. An example of a phenotype would be blue or green eyes, while the genotype is that at the microscopic level. Genotypes can be predicted by using a Punnett square. A dominant gene is a gene that is always expressed, which a recessive gene is only expressed if there's no dominant present. Genes are actually expressed by the creation of proteins. This connects to the project because every suspect has unique genes and phenotypes to themselves.
DNA Mutations
A mutation is a random change in the nucleotides of DNA. It usually occurs during DNA replication. Radiation can also cause a mutation.
Base Substitution - Also called a point mutation, this is when a nucleotide is switched with another. There are two types. A transition is when a purine (A, G) is replaced with another purine or when a pyrimidine (T, C) is replaced with another pyrimidine. A transversion is when a purine is replaced with a pyrimidine or vice versa.
Silent - When a base substitution has no effect on the proteins created, it's considered silent.
Missense - When a base substitution changes the polypeptide sequence, it's considered missense.
Nonsense - When a base substitution results in a premature stop codon, it's considered nonsense.
Deletion - This mutation is when a nucleotide is deleted from the DNA sequence.
Insertion - This mutation is when a nucleotide is added to the DNA sequence.
There are many diseases that are caused by mutations. The following are a few examples.
Huntington's Disease - This disease causes a break down of brain cells and the brain. Sam Sophomore has this disease and Nancy Normal might have it.
Marfan Syndrome - This disease affects the body's connective tissue. People with the disease are generally taller and have long legs, arms, and fingers. Fred Flimmer has this disease.
Achondroplastic Dwarfism - This is the most common kind of dwarfism. Glen Glee has this disease.
Base Substitution - Also called a point mutation, this is when a nucleotide is switched with another. There are two types. A transition is when a purine (A, G) is replaced with another purine or when a pyrimidine (T, C) is replaced with another pyrimidine. A transversion is when a purine is replaced with a pyrimidine or vice versa.
Silent - When a base substitution has no effect on the proteins created, it's considered silent.
Missense - When a base substitution changes the polypeptide sequence, it's considered missense.
Nonsense - When a base substitution results in a premature stop codon, it's considered nonsense.
Deletion - This mutation is when a nucleotide is deleted from the DNA sequence.
Insertion - This mutation is when a nucleotide is added to the DNA sequence.
There are many diseases that are caused by mutations. The following are a few examples.
Huntington's Disease - This disease causes a break down of brain cells and the brain. Sam Sophomore has this disease and Nancy Normal might have it.
Marfan Syndrome - This disease affects the body's connective tissue. People with the disease are generally taller and have long legs, arms, and fingers. Fred Flimmer has this disease.
Achondroplastic Dwarfism - This is the most common kind of dwarfism. Glen Glee has this disease.
Other Important Concepts
Fingerprinting - This is a forensic science method that involved matching fingerprints with people. Every person has different fingerprint. The 3 major fingerprint types are arch, loop, and whorl. Nancy's fingerprint matched with one that was found near Carelton Comet.
Ink Chromatography - This is a method that involves separating the pigments in ink by dipping it into a solution. Nancy and Sam both had a pen that matched the one that wrote the death note.
Blood Type - The 4 major blood types are A, B, AB, and O. Every blood type also has an Rh factor. Nancy's blood type matched with one found on the knife.
Karyotypes - This is a visual representation of one's chromosomes. It shows all the chromosomes of a person. Nancy's karyotype matched with a karyotype found at the crime scene.
Pedigrees - This is a diagram that is used to track a certain gene or disease in a family. It also shows who's dead and the family relations.
DNA Fingerprinting - This is a method that shows the characteristics of DNA by using gel electrophoresis. Nancy's DNA matched with the crime scene.
Chromosomal Disorders - A chromosomal disorder is a disorder that involves the chromosomes of a sufferer. There are many kinds of chromosomal disorders.
XYY Syndrome - Also called Jacob's Syndrome, this syndrome affects only men. It is caused by an extra Y chromosome. People with this disease are taller than normal, have acne, and are at higher risk for learning problems. Sam Sophomore and Carelton Comet both have this disease.
XXX Syndrome - This syndrome affects women and is caused by an extra X chromosome. People with this disease are taller than normal, have flat fleet, and have learning problems. Nancy Normal has this disease.
XXY Syndrome - This syndrome affects men and is caused by an extra X chromosome. People with this disease are skinnier, more feminine, and have less facial hair. Fred Flimmer has this disease.
Down Syndrome - This syndrome is caused by an extra 21st chromosome. People with this disease have slanted eyes, a shortened neck, and learning problems. Theresa Terra has this disease.
Ink Chromatography - This is a method that involves separating the pigments in ink by dipping it into a solution. Nancy and Sam both had a pen that matched the one that wrote the death note.
Blood Type - The 4 major blood types are A, B, AB, and O. Every blood type also has an Rh factor. Nancy's blood type matched with one found on the knife.
Karyotypes - This is a visual representation of one's chromosomes. It shows all the chromosomes of a person. Nancy's karyotype matched with a karyotype found at the crime scene.
Pedigrees - This is a diagram that is used to track a certain gene or disease in a family. It also shows who's dead and the family relations.
DNA Fingerprinting - This is a method that shows the characteristics of DNA by using gel electrophoresis. Nancy's DNA matched with the crime scene.
Chromosomal Disorders - A chromosomal disorder is a disorder that involves the chromosomes of a sufferer. There are many kinds of chromosomal disorders.
XYY Syndrome - Also called Jacob's Syndrome, this syndrome affects only men. It is caused by an extra Y chromosome. People with this disease are taller than normal, have acne, and are at higher risk for learning problems. Sam Sophomore and Carelton Comet both have this disease.
XXX Syndrome - This syndrome affects women and is caused by an extra X chromosome. People with this disease are taller than normal, have flat fleet, and have learning problems. Nancy Normal has this disease.
XXY Syndrome - This syndrome affects men and is caused by an extra X chromosome. People with this disease are skinnier, more feminine, and have less facial hair. Fred Flimmer has this disease.
Down Syndrome - This syndrome is caused by an extra 21st chromosome. People with this disease have slanted eyes, a shortened neck, and learning problems. Theresa Terra has this disease.
Reflection
This project went very well for my group. The project itself was very unique and engaging as well. I had a good mix of strengths and weaknesses. Some of my strengths were my actual work on the presentation and how I presented the end of it. I spent a lot of time at home working on the presentation. I added an intro animation, pedigrees, and motives. All of these additions were important for our group's success. Another strength of mine was the end of our actual presentation. At the end of the presentation when I was summarizing the proof of Nancy being the murderer, I drove it home and put a lot of effort in the end. My speech helped convince the judges that we were right about our charge.
I had some strengths, but I had some weaknesses. My weaknesses were interaction with my group and staying on task. Because I did so much of the presentation at home, I didn't interact much with my group mates and added in a lot that they didn't necessarily know about until the day of the presentation. It would've been better if I told them about it first. During the work days, I sometimes got off task. We worked in the solar studio and were away from everyone else. It was difficult for me to focus at times because I got off task on my phone and people went in and out of the studio.
I did have noticeable weaknesses, but my strengths compensated for them. This project was unique and interesting and I'm ready to start the next one.
I had some strengths, but I had some weaknesses. My weaknesses were interaction with my group and staying on task. Because I did so much of the presentation at home, I didn't interact much with my group mates and added in a lot that they didn't necessarily know about until the day of the presentation. It would've been better if I told them about it first. During the work days, I sometimes got off task. We worked in the solar studio and were away from everyone else. It was difficult for me to focus at times because I got off task on my phone and people went in and out of the studio.
I did have noticeable weaknesses, but my strengths compensated for them. This project was unique and interesting and I'm ready to start the next one.