Ensaio opcional 10 março 2017
One of the wonders of the Central Dogma of Molecular Biology is its universality, in fact the universality of the genetic code, which is the same for all organisms. This means that it is possible to compare all living things to each other. Despite it seems a simple and obvious idea, this is a big step for understand the tree of life and the beginning of life. If before, it was not possible to compare fungi with animals or plants with prokaryotes, due to the absence of ‘’something’’ in common, it is now. Nowadays, with a range of tools, it is possible to compare sequence of the human, of the bacteria that causes tuberculosis and sunflower.
Revisado por Filipe Gudin: Um dos primeiros pontos que podem ser abordados a respeito do teu texto é a formalização da sentença-chave. Como o tema central é a universalidade do dogma central, seria possível encerrar o período logo em “… is its universality.” e aí continuar a ideia em outra sentença, como “In fact, the universality of the genetic code can be seen in all organisms, enabling comparative studies.”. Os períodos estão objetivos e curtos, porém os achei um pouco repetitivos, sempre se referindo à comparação. É possível perceber isso pela presença do verbo “compare” em quase todos eles. Seria interessante explorar um pouco mais o por quê essa comparação é possível, comentando sobre o fluxo de informação ou sobre o própprio código genético, por exemplo. Por causa dessa repetição, senti que o período final não é uma conclusão, mas mais um exemplo relativo ao período anterior. Dessa forma, o texto terminou de uma forma suspensa, deixando o leitor esperando algo a mais para fechar o raciocínio.
Ensaio 1 17/03/2017
The replication of the DNA is made in a semi- conservative model. This mean that the double helix splits in two, and each of the strands serves as a model for a new strand. This seems pretty obvious, but actually it’s not, or batter saying was not. There where tree possible hypothesis that the DNA replications occurred, a conservative model, semi-conservative model and dispersive model. After the Meselson & Stahl experiment, it was clear that the DNA replication is made under a semi-conservative model. Basically the experiments of Meselson& Stahl, they cultured bacteria in a culture containing heavy and not heavy nitrogen, and in each generation observed the proportion of heavy and not-heavy nitrogen.
Revised by Deyvid Amgarten
The assay talks about the models of replication for the DNA molecule. However, a topic sentence is absent and this idea is not passed in the very beginning of the paragraph. There are some minor English typos, as in: "This mean" (This means) and "There where" (There were). I suggest the author to avoid sentences like "This seems pretty obvious…" in scientific text. Last, but not least, I missed some conclusion sentence in the text to sum up the text principal idea.
Natural selection is one of the most popular terms in the field of evolution. Was postulated by Darwin as an explanation of adaptation and speciation. Natural selection act as a selective force on the organisms, leading to the nowadays diversity. However would this be the only force acting on the organisms? The answer is no. Kimura, demonstrate that in the molecular level many mutations occurs. Not because this mutation have an adaptive value and gives the individual better fitness. Mutation or nucleotide substitution happens all the time, and most of the times they are natural. That means that they not are perceived in the phenotype. So they not necessarily are adaptation.