Genetic Traits

 In biology class we collected data of different genetic traits from our family members and classmates.  Then we compared our result to see if we could figure out our genotypes.  The genetic traits included tongue-rolling, attached or unattached ear lobe, hitch hiker's thumb, and widows peak.  After completing a survey on my immediate family members, I came up with these results:

  From an outside source I was able to find that tongue rolling is a dominant trait, unattached earlobes are dominant, straight thumbs are dominant, and widow's peaks are dominant.  Using this information it is possible to predict what my family's genotypes are.  Since tongue rolling is a dominant trait, and my mother, Pamela, cannot roll her tongue, she definitely has a homozygous recessive (tt) tongue-rolling gene. My father, Carl II, on the other hand, can roll his tongue, which opts for two possible options: he either has a homozygous dominant (TT) gene, or a heterozygous (Tt) gene.  Since all of Pamela's and Carl II's children can roll their tongues, it is quite probable that Carl II has indeed a homozygous dominant tongue-rolling gene, as this punnett square shows.

Attached vs. unattached earlobes seemed to be the most controversial survey taken, therefore the following results may lack accuracy.  Carl II, who has unattached earlobes, and Pamela, who has attached earlobes, produced three children with unattached earlobes and one child with attached earlobes.  Since unattached earlobes are the dominant trait, Pamela definitely has the homologous recessive genotype (ee).  Then we can predict that Carl has the heterozygous genotype, since most of his offspring have unattached earlobes, but one of them have attached.  

   As for hitch hikers thumb, I concluded that both my parents have the homozygous recessive gene (hh), as well as all of us offspring.  Straight thumbs are dominant, and therefore the offspring of a person who carried that gene would have a chance of having a straight thumb, even if the other parent was homozygous recessive.  Out of four kids all of us have hitch hiker's thumb, therefore having homozygous recessive hitch hiker thumb genes.  Although, there is still a chance that one of my parents are heterozygous.

   Widows peak is a dominant gene.  Carl II has a widow's peak, his wife does not, and neither do any of his children.  This means that Carl II probably has the heterozygous widow's peak gene (Ww) and Pamela has the homozygous recessive gene along with the rest of her children (ww).  

   Next I compared my findings with my class results.

What I found the most interesting about this was that the dominant traits are not always the most common.  For example, Widow's peak is a dominant gene, however less than half of our class have them.

Forensics

     Forensic science is any type of scientific tests or techniques used in the investigation of crimes.   Forensic scientists are the ones who provide the scientific proof to prove a criminal guilty or a person innocent in court.  Real forensics is a little bit different then the media portrays it to be in shows like Law and Order, CSI, or NCIS, but it is still very interesting.

   A variety of techniques and tests are used to provide evidence for a criminal investigation such as modern computer and clay facial reconstruction, DNA fingerprinting, autopsy techniques, forensic anthropology, and toxicology.  DNA fingerprinting is an especially useful part of this.
    As we all know, DNA is a sequence of nucleic acids that code for protein creation and basically are the directions for all living things.  No two people have the same DNA sequence, and scientists have found how to make a DNA profile of an individual in order to identify that person.  They scan 13 specific regions of DNA, which are called loci.  These locus points are different in every person, and the chance that two people will match at all thirteen sites is very small (1 in 400 trillion).
     When crime scene investigators find any type of evidence at a crime scene that can be tested for DNA, such as hair or blood, it is taken to a lab.  There the DNA is extracted by a chemical technique similar to that of the DNA necklace experiment our class conducted.  If this technique doesn't isolate enough DNA to analyze, scientists artificially increase the strand by adding DNA polymerase to the extracted DNA strand.  The polymerase catalyzes DNA synthesis, and the DNA strand is replicated, creating enough DNA for analysis.  Fluorescent molecules are attached to the certain parts of the DNA, and then the DNA is run through a DNA sequencing machine that makes the DNA fingerprint that can be compared.

      Nowadays scientists are working on isolating specific genes that code for specific things.  For example scientists are now able to identify the part of the DNA responsible for inherited traits.  This can make reveal the suspect's hair or skin color and help solve a crime.  In the future scientists will be able to figure out what height or race a person is.  They are even researching how to build a model of a suspect's face from DNA found in evidence, like a single drop of blood.  The possibilities are unknown, but DNA in forensics certainly helps solve a lot of crimes and bring justice to people.  For example, it helped identify bodies after 9/11.  For more information on that: http://www.terradaily.com/reports/Sept_11_Panel_Makes_Recommendations_For_DNABased_ID_After_Mass_Disasters.html
     There are some moral/ethical issues surrounding this topic.  CODIS, which is the COmbined DNA Index System, stores DNA fingerprints of DNA collected at crime scenes and of convicted offenders.  The privacy of this index is definitely a concern.  Usually once a sample is stored in the index it is never destroyed, so peoples' entire genetic makeups are up for grabs.  Genes can reveal many aspects about a person including susceptibility to particular diseases, legitimacy of birth, and maybe even behavioral aspects and sexual orientation. 
Sources:

http://library.thinkquest.org/04oct/00206/pti_dna_matching.htm

http://www.ornl.gov/sci/techresources/Human_Genome/elsi/forensics.shtml#6