This season was all about genetics, DNA replication, and Protein Synthesis. In the first chapter of this unit, chapter 14, the class used Z space to learn about Mendel's laws of genetics. The first law being the Law of Segregation, which states that each parent gives one allele to its offspring and one of the traits is displayed based off of these alleles.There are two types of alleles, dominant and recessive. A recessive allele is the allele that carries a recessive trait. Meaning, in order for the recessive allele to be seen in an organism, the organism must have two recessive alleles, one from each parent. Dominant alleles are alleles that code for dominant traits. For dominant traits, there only needs to be one dominant allele present in order for the trait to be expressed. For example, if one parent passes down a recessive allele, r, and the other parent passes down a dominant allele, R, then the genotype will be Rr but the dominant trait will be expressed. This example helps to show the next Mendelian law, the Law of Dominance. The law states that when a dominant allele is present in the genetic make- up, or genotype, of an organism, it will be expressed in the organism. The physical expression of a trait in an organism is called the phenotype. When an organism has two different alleles, Rr, the trait is heterozygous. When an organism has two of the same alleles, rr or RR, the organism is called homozygous recessive or dominant based off of the alleles. The final
Mendelian law was the Law of Independent Assortment, stating that a trait is independently inherited of other traits.
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Although not from this class, this image shows how zSpace can be used to innovate the classroom by showing a 3D representation of what you are studying.
Citation: Zspace Header. N.d. Buckeye Education Systems. Web. 15 Dec. 2016. <http://buckeye-edu.com/interactive-tech/>.
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In the following chapter, chapter 15, the class learned about pedigrees, pungent squares, and types of inheritance of traits as well as genetics that don't follow
Mendelian laws. There are four main types of inheritance, autosomal recessive, autosomal dominant, or sex- linked. Autosomal recessive and dominant traits mean that the traits are carried/ passed down on genes that are not found on sex chromosomes, X and Y. Sex- linked traits are traits that are found on only the X or Y chromosomes. Also, the class learned about traits that do not follo
w Mendelian laws. For example, pigmentation of the skin is related to many traits, not just one, this is called polygenic traits. There are many other types of non-
Mendelian genetics like codominance, which is when an organism is heterozygous but does not display the dominant allele, but a mix of the dominant and recessive alleles. There is also epistasis, which is when a gene controls how another gene functions (one gene acts as a light switch for the other gene turning it on or off). To apply these new teachings, each person in class in a group of three or two researched a specific genetic disorder and created a voice thread about the disorder that they researched. Each voicethread included the type of inheritance of the disorder, where the mutated gene was located, symptoms of the disorder, how the disorder affects an individual, and lastly to interview a person who has or works with this specific disorder and include the interview into the voicethread in some way. The genetic disorders varied from eye cancers, to muscular
dystrophy, to 22q11.2 deletion syndrome. Then, every student needed to individually comment on each voicethread discussing grows and glows. Another activity we did to better understand genetics was watch the documentary Cracking the Code of Life. This documentary followed how Celera and the Human Genome Project connected to solving many genetic mutations and the technologies that are being used to cure and find treatments for cystic fibrosis, Tay Sachs, cancers, and many other types of illnesses. Check out AP Bio Rockstars for posts about Cracking the Code of Life documentary as well as for links to look at thevoicethread projects!
Chapter 16 was all about the replication of DNA. In order to help better understand, we created our own DNA in class. Using paper, we drew out a DNA molecule on green paper. We then used helicase, scissors, to open and unwound our DNA. Then, a new nucleotides are matched up by DNA polymerase in the 3' to 5' direction of the original strand. Polymerase can only read DNA in the 3'- 5' direction, but since DNA is anti-parallel, DNA polymerase cannot read the other half of the original DNA strand, called the Lagging Strand. Thus, an enzyme called primase makes RNA primers on the lagging strand of DNA telling Polymerase when to start and stop, called Okazaki fragments. Ligase, tape in the representation done in class, then sticks these fragments together. The result is two identical DNA molecules.
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DNA Replication activity that we did in class! Green represents the original strand of DNA while the pink represents the newly formed sections of DNA which results in two identical DNA molecules
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Finally, in chapter 17, we talked about transcription, translation, and RNA to produce proteins. To help us better understand protein synthesis we played a game in which each person played a different molecule or organelle that participated in the synthesis of proteins. The roles were mRNA, rRNA, tRNA, and Golgi apparatus. The person playing mRNA's job was to go to the nucleus, Mrs. Girard, and copy a strand of DNA into a strand of RNA that would be brought to the ribosome where the rRNA would transfer this code into anti- codons that the tRNA would then find in the cell, the classroom. This would build a sentence that represented a protein. The job of the Golgi apparatus was to double check the sequences given by the mRNA and rRNA and make sure that the sentence made sense. Then, the message was returned to the nucleus, but in reality the proteins would be processed and shipped internally or to another cell.
