Please answer the following questions in a 200-word response minimum. Try your best to reference the text I will message you privately for how to access the text book.
1. DNA Replication shows the need for telomerase-mediated reactions to maintain chromosome length after replication. How would you explain the relationship between DNA replication, telomerase activity, and aging and cell death?
2. A topic I would like to bring to your attention is the functions of DNA. It would be very difficult if the DNA was held in just one place. If DNA were held in just one cell, just imagine what would happen if that cell was destroyed. Then what? There would be no way for any of the cells to gain the genetic information that it would require for survival. Anyway, the question I would like to pose to the class is what are some functions of DNA?
3. There are four different bases that make up DNA. Every living organism that we know of utilizes the same four bases. So that gives you some idea of how many different combinations of those same four bases are utilized. The backbone of DNA consists of a phosphate, five carbon sugars, and a base. The question that I would like to post to the class is what is the importance of the bases in the process of translation?
4. Given that the genomes of all organisms are made up of As, Ts, Cs, and Gs, how does one account for diversity in organisms? What are some factors that could adversely affect diversity in nature?
5. Based on what we know about DNA, do you think it makes more sense for DNA to be genetic material versus RNA or protein? Why do you think alternative forms of DNA have been found by various researchers?
Please participate (respond) to the classmate's answers with POSITIVE notable and educational input. (200 word minimum Reponses)
1. Micah: Telomeres are ends of eukaryotic chromosomes like the tips of shoelaces. They are essential to the lifespan (aging) of human cells. If Telomeres are frayed (during replication), then DNA strands lose their effectiveness which eventually leads cells to become ineffective, too, just like in the case of endless shoelaces that would cause one to trip. The shorter the telomeres, the older and more fragile cells are. Telomeres function by preventing chromosomes from losing base pair sequences at their ends. According to UT Southwestern Medical Center, "Telomerase, also called telomere terminal transferase, is an enzyme made of protein and RNA subunits that elongates chromosomes by adding TTAGGG sequences to the end of existing chromosomes".
Facts about Telomeres and Telomerase. (2016). Retrieved from https://www.utsouthwestern.edu/labs/shay-wright/research/facts-about-telomeres-telomerase.html
2. Anthony:The double-stranded nature of DNA, as opposed to the single-stranded nature of RNA, further contributes to the favorability of DNA as the genetic material. The double-helix structure of DNA places bases inside the structure, protecting the genetic information from chemical mutagens -- that is, from chemicals that react with the bases, potentially changing the genetic information. In single-stranded RNA, on the other hand, the bases are exposed and more vulnerable to reaction and degradation. Also, when DNA is replicated, the new double-stranded DNA molecule contains one parent strand which serves as the template for replication and one daughter strand of newly synthesized DNA. If there is a base mismatch across the strands, as often happens after replication, the cell can identify the correct base pair from the parent DNA strand and repair it accordingly. Since RNA is single-stranded, it cannot be repaired in this way. The varies adverse and beneficial conditions through the world have resulted in the alteration of DNA.
Graw, M. . (n.d.). Why DNA Is the Most Favorable Molecule for Genetic Material & How RNA Compares to It in This Respect. In Synonym. Retrieved August 23, 2016, from https://classroom.synonym.com/dna-favorable-molecule-genetic-material-rna-compares-respect-17806.html.
3. Micah: There are several different examples of molecular and environmental factors that can cause diversity in organisms. Although the nucleotide bases are the same alphabet to choose from for organisms, the core of diversity relies on the variety in the sequencing of these four letters. Not every individual has the same exact rows of sequenced 3-base nucleotides, even though every organism is choosing from the same pool of the four-letter genomic alphabet. One example of diversity cause and effect are: mutations. Three bases (nucleotides) make up one amino acid. Chains of amino acids result in a protein. Depending on the genetic mutation that occurs will determine the effectiveness of the protein. The addition of one or nucleotides alone causes a "frameshift" mutation in which all of the following groupings of codons are changed, resulting in all of the amino acids inserted after the addition being incorrect.
Nevertheless, "the amino acids coded for before the deletion will not be affected and will still be correct" according to links from highered.mheducation.com. A nucleotide deletion in DNA replication will cause all of the amino acids inserted after the deletion to be incorrect while all of the groupings of codons will change. Because amino acids are built in three nucleotides, the deletion or addition of three bases would be least detrimental to the organism because the most certain it can do is code for a whole new amino acid instead of causing a frameshift like the other cases.
If mutations are only one example of diversity in organisms, what other common examples can be observed, class? Is it possible that some factors occur at higher frequencies than others in order to create such diversity? And which pieces of molecular information ensure that a banana is a banana, while a monkey is a monkey?
Reference
Addition and Deletion Mutations (2016). McGraw-Hill Global Education Holdings, LLC. Retrieved from https://highered.mheducation.com/novella/MixQuizProcessingServlet