The discovery of ribozymes supported the RNA World Hypothesis.RNA folding is typically mediated by the same type of base-base interactions that are found in DNA, with the difference being that bonds are formed within a single strand in the case of RNA, rather than between two strands, in the case of DNA.During transcription, an RNA copy of a segment of DNA, messenger RNA (mRNA), is made.According to the RNA World Hypothesis, life later evolved to use DNA and proteins due to RNA’s instability relative to DNA and its’ poorer catalytic properties.Donna Blackmond, a chemist at Imperial College London, stated that “this is extremely strong evidence for the RNA world.
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That is the scientific process – a carefully structured, meticulously researched effort to explain some aspect of our world.Science is a body of knowledge about the living world – of insights about nature- ,the evidence for which is a vast array of facts.This may sound like science is very inexact, but in fact, this is the reason that science has come up with so many accurate descriptions of how the world works.There is a hierarchy of organization in the living world.A theory is as close as we will get to most of the “facts” about the world we study.
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Such type of hypothesis in which daughter DNA molecules contain one parental strand and one newly-replicated strand.The enzymes also require the presence of an oligomeric RNA segment as a primer.When replication of DNA molecule is completed newly synthesized strand has primer RNA.In this way newly replicated DNA appears as a hybrid of DNA and RNA, with gaps in the newly synthesized strands.This hypothesis was also rejected due to lack of evidence.
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The endosymbiotic theory has not always gained acceptance by some biologists, and many other hypotheses exist in the biological world on the evolution of the eukaryotic cell.Ribosomal RNA ... Phylogenetic analyses based on ribosomal RNA (rRNA) sequences are one of the standard methods of inferring relationships among diverse organisms.The endosymbiotic theory was criticised in 1998 by Martin and Muller stating that the need for energy exchange in ATP drove the establishment of mitochondrial endosymbionts, this was known as the Hydrogen Hypothesis.But despite the theory being laughable when first proposed, it has now gained the acceptance from many top biologists including Doolittle and Brown in 1994 who stated “the endosymbiont hypothes...
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Evidence of chloroplast and mitochondria having their own DNA supported the endosymbiosis hypothesis.Also, mitochondria share similar characteristics with aerobic bacteria just how chloroplasts are similar to photosynthetic bacteria.It explains that all of the organelles in a eukaryotic cell broke off from the prokaryote cell and soon created a eukaryote cell in which each organelle had its own function within the new cell.The autogenetic hypothesis states that eukaryotic cells evolved from prokaryote cells.Two prokaryote independent cells existed, one was a host cell whereas the other was an independent chloroplast or mitochondria.
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Quantitative evidence supporting this so-called ‘error minimisation’ hypothesis was first provided by Haig and Hurst (1991).The ‘ambiguous intermediate’ theory proposes that codon reassignment involves an intermediate stage during which the codon is read by both cognate and a mutant transfer RNA (tRNA) (Schultz and Yarus 1994).Schultz, D. W. & Yarus, M. 1994, ‚Transfer RNA mutation and the malleability of the genetic code’, , vol.Experiments to study the binding of RNA aptamers (short RNA molecules) to amino acids demonstrated that those aptamers selected from random sequence mixtures by amino acid binding were significantly enriched with cognate codons for the respective amino acids (Knight and Landweber 1998).Later, this hypothesi...
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These clues suggest that DNA-bound enzymes appeared during an "early age" in the DNA world, where RNA cells and RNA and DNA viruses existed.The hypothesis of an RNA world, which is now popular with scientists, is based on the discovery that ribonucleic acid (RNA) can both be the support of genetic information, such as DNA, and performing metabolic tasks, such as proteins.The relevant polymerization has probably been that of RNA nucleotides, initiating the early stages of an RNA world.The ribonucleic acid (RNA) world hypothesis is that RNA was the main - and arguably the only - form of polymer supporting metabolism, before the emergence of the first DNA cell.RNA viruses would here be relics of the RNA world, U-DNA viruses would then be re...
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Rifampicin is an antibiotic which in bacteria affects the RNA polymerase.At some stage in eukaryogenesis, cellular and genomic combination of the two different organisms (which vary for the hydrogen and syntrophy hypothesis) happened with gene transfer from bacteria to archaea and then subsequent replacement.Moreover, both of these organelles contain the operating systems required for cellular functions such as protein synthesis, for example ribosomes and transfer RNA, and also the cellular constituents needed for translation.It does not have this effect on eukaryotic RNA polymerase however does inhibit mitochondrial RNA polymerase.This hypothesis is based on similar metabolic considerations as the hydrogen hypothesis proposed by Martin ...
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(12) Also, the antibiotic rifampicin which inhibits the RNA polymerase of Bacteria has been found to inhibit the RNA polymerase within bacteria.Support for the endosymbiosis hypothesis can be found in the physiology and metabolism of mitochondria and chloroplasts, as well as the structure and sequence of their genomes.The second hypothesis, also known as the hydrogen hypothesis, states that the bacterial ancestor of the mitochondrion was taken up by a member of the Archaea via endosymbiosis, and from this association, the nucleus later emerged, followed by a later acquisition of the cyanobacterial ancestor of the chloroplast.Hence, it is no surprise that both these organelles contain 70S ribosomes typical of prokaryotic cells, and show 1...
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RNA is used today in a number of applications in molecular biology, in particular thanks to the process of RNA interference, which consists of the introduction into eukaryotic cells of short fragments of double-stranded RNA called "small interfering RNAs".The discovery of RNA with catalytic capacities was made in the 1980s, in particular by the Thomas Cech's team, who worked on the introns of the ribosomal RNA gene of the ciliated protozoan Tetrahymena, and Sidney Altman, who studied ribonuclease P, the tRNA-processing enzyme.This theory, known as RNA world hypothesis ("RNA world hypothesis"), makes it possible to get rid of a paradox of the egg and the chicken which arises when one seeks to know which proteins (catalysts) and which DNA ...
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How might similarities and differences in genetic codes, or the proteins built as a result of these codes, be used to determine how closely related different species are?Explain your answer.Although, this is just a theory, but can support the beginning of life.The next closest to humans and chimps are horses, because on the chart there are 3 differences and the rest are similar .A universal genetic code takes the similarities in organisms and compares them to suggest that each organism came from a single organism from early Earth.
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Evolution is a theory and not a hypothesis because evolution has been proven by vast amounts of scientific data, research, and testing.The definition of a hypothesis is an educated explanation that needs to be researched and tested but has not yet been proven (Earman, 1984).The fossil record is evidence of evolution.Darwin's Spectre : Evolutionary Biology in the Modern World.Smith, T. M., & Smith, R. L. (2009).
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Therefore, no RNA was present on this slide.This would indicate the presence of DNA, which was stained green by the methyl green, and the absence of RNA which was supposed to be stained red by the pyronin.In the nucleus, RNA does exist and was expected to be stained red.The slide that was only stained with MGP contained both DNA and RNA, which can be concluded from the fact that the cell was stained green in the nucleus and rose-red in the cytoplasm.There are different forms of RNA each have different functions: messenger RNA, ribosomal RNA and transfer RNA.
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Overview: Inquiring About the World of Life .o The sequence of nucleotides along a gene is transcribed into RNA, which is then translated into a specific protein with a unique shape and function.• Posing questions about the living world and seeking science-based answers are the central activities of biology, the scientific study of life.• In spite of the body of evidence supporting a widely accepted theory, scientists may have to modify or reject theories when new evidence is found.• Compared to any one hypothesis, a theory is generally supported by a much more massive body of evidence.
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In January 2009, Joyce’s project resulted in his 24 RNA variants reproducing.However, he felt that this hypothesis would be impossible to prove since the life that is present would prevent new life from emerging.However, this process is only conceivable if RNA can sustain evolution on its own.Additionally, at a recent symposium called “The Future of Life” human genome pioneer Craig Venter explained the hunt for genes around the world.This theory promotes that life as we know it is based on DNA proteins with RNA acting as a courier of genetic information.
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The electron cryomicroscopy and image analysis of New World Pichinde and Tacaribe arenaviruses and Old World lymphocytic choriomeningitis virus has revealed pleomorphic enveloped particles ranging in diameter from ∼400 to ∼2,000 (angstroms) and are occasionally filamentous, reaching more than 20 μm in length ( 76 ).While there is considerable evidence for this mechanism, it has proved difficult to directly demonstrate the lipid molecule displacment after proteins are inserted.Also there are two objects that look like beads labelled L and S these are the encapsulated viral RNA genomes, the beads are in fact nucleoproteins that are wraped around the RNA genomes and protect them from host cell degradation attack.From Chapter 1, it was re...
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V. Translation = De-coding RNA into protein .A nucleic acid very similar to DNA, called mRNA or messenger RNA, is a copy of a gene, and serves this function the “bridge” between DNA and protein: The Central Dogma:DNA encodes the information to make RNA and RNA molecules function together to make protein| .tRNA = transfer RNA; small RNA molecules that carry a specific amino acid at one end and an anticodon region that recognizes and binds mRNA at the other end.* When the mRNA gets into the cytoplasm, it is made into protein * Complete transcription of an RNA molecule.rRNA = ribosomal RNA; these RNA molecules associate with other proteins to form the ribosomes.
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The molarities of RNA hybridization to each fragment are given beneath each, with their standard deviations (s.d.).The process involves the recognition of that conserved polyadenylation motif, RNA cleavage and polyadenylation.The nuclear RNA, cytoplasmic RNA, and 5sRNA marker showed peaks as seen in the figure alongside.The initiation signal that carries out polyadenylation is none other than the cleavage signal which attracts the cleavage enzyme that specifically recognizes the AAUAAA motif and cuts the RNA 20 nucleotide downstream.Maurice Sussman, in 1970 gave the ‘ticketing’ hypothesis which encompasses the theory of each RNA having a ticket to gain entry to the ribosome and further ticket punching everytime it got translated.
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The second hypothesis, in contrast, considers that there could have been a nucleus was formed after the acquisition of the protomitochondrion, when a member of the Archaea acquired the bacterial ancestor of the mitochondrion through endocytosis11.However, Margulis reasoned that, if the endosymbiotic hypothesis represents the true course of events in the evolution of mitochondria, then upon entering a symbiotic partnership, the symbionts would lose all synthetic capabilities except the ability to replicate their own DNA.An alternative hypothesis has recently been forwarded by Davidov and Jurkevitch, who propose that the ancestors of mitochondria were not endocytosed by Archaea but were predators that penetrated the host and devoured the h...
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The exons will in turn be sutured to give mature RNA by this splicing mechanism.An intron is a portion of a gene which is transcribed into RNA, within a precursor RNA, and which is then eliminated by a programmed excision process and which is therefore not found in RNA mature.We will therefore obtain an RNA of type Exon 1 - Exon 2 - Exon 3 - ... - Exon n .After transcription, the synthesized precursor RNA will undergo a a number of modifications, including splicing, during which introns will be excised from the RNA.Excision of the intron by a spliceosome is quite specific: the complex will cleave the intron by a transesterification of the phosphodiester bond to its 5 ', to reattach it at the branch box by forming an unusual 5'-2' phospho...
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While they are not the text book example of living organisms, is has been in agreement that there always will be exceptions to the rules.In retroviruses, the RNA gets transcribed to DNA bye the enzyme reverse transcriptase.Viruses deserve to take their rightful place among the ranks of living organisms.While viruses are inactive when in transport between hosts, the arguements are overwhelmingly in favor of considering viruses living organisms.The nucleic acid core is composed of either DNA or in the case of retroviruses, RNA, but never both.
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Although the confocal-microscopy images support this case for siRNA, there is no data provided to support the shRNA claim made.Figure 1d shows similar analytical techniques to those discussed in Figure 1a and b and supports the hypothesis that S33Y-transfected cells reduce E-cadherin promoter activity, and, that silencing of Snail1 by si/shRNA inhibits the invasive activity of these cells thus restoring E-cadherin promoter activity.Suggest two experiments that could be done to support the conclusion.Figure 1 is subdivided into four panels: 1a-1d – each visually recording results of experiments investigating particular questions that collectively challenged the hypothesis to test its validity.The diagram effectively supports the hypothesi...
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The viral genomic RNA is encapsulated in a ribonuclear protein (RNP) complex (nucleocapsid) consisting of the nucleoprotein (NP), minor nucleoprotein (VP30), VP35, and polymerase (L) protein .As with all RNA viruses with a negative sense genome, EBOV virus must package its own RNA-dependent RNA polymerase (RDRP) so that it can initiate transcription and replication.First, we hypothesized that the occlusion of surface MHC1 molecules would have the functional consequence of blocking antigen presentation to CD8 T cells, thereby preventing their activation.EBOV is a member of the family in the order , and so encodes its genome in single-stranded linear RNA in the negative orientation.We have found this to be the case, and have describe...
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RNA contains uracil in place of thymine .This is one of the main lines of evidence that support the hypothesis of an RNA world.RNA has been shown to catalyze certain reactions (as part of ribosomes, rRNA participates in the catalysis of the peptide bonds that form proteins).RNA has both information storage and catalytic properties.In addition, single-stranded RNA molecules can assume a variety of three-dimensional shapes specified by their nucleotide sequences.
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The second hypothesis, in contrast, considers that the nucleus was formed after the acquisition of the protomitochondrion through endocytosis by a member of the Archaea 9.The loss of synthetic ability in mitochondria therefore supports Margulis’ hypothesis and explains why the mitochondrial genome is so small when compared to nuclear genomes in Table 2. .Another example, rifampicin, inhibits the RNA polymerase of bacteria and mitochondria, but has no such effect on eukaryotic nuclear RNA polymerase.What the endosymbiotic hypothesis does not make clear is the order of events regarding the formation of the nucleus and the acquisition of the prokaryotic cell containing the precursor mitochondrial genome.This is known as the hydrogen hypothe...
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One of the modules in this tool able to identify sets of functionally similar genes, then make summarization of gene sets into meta gene and finally apply the statistical analysis on it.On the other hand, GeneXPress is a general purpose of visualization and analysis tool that designed to support extensive post-analysis of gene expression experiments.We acknowledge support by Dr. Razib Othman Senior Lecturer of Department Software Engineering, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia who supervised and guide us throughout this study by giving a lot of helpful comments.A class of small non-coding RNAs which known as a microRNAs (miRNAs) control the gene expression by targeting mRNAs and trigger either translation repressio...
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MicroInspector: a web tool for detection of miRNA binding sites in an RNA sequence .test this hypothesis.However, functional studies are necessary to test this hypothesis.Using the program mFold and Genebee, we determined the potential effect of the SNP sequence alterations on RNA folding.The role of structure on RNA function is akin to that of protein.
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Why is it considered unreliable supporting scientific information?Face outward Why?Proteins – provide structural support, metabolism (enzymes), immune defense, body regulation& resort energy source after carbohydrates and lipids with amino acids as subunits Nucleic Acids – (DNA & RNA).Do the heads of a phospholipid bilayer face outside or inside of a cell membrane?Then formulate a hypothesis trying to come up with a solution, after more observation of the hypothesis & then finally draws a conclusion.
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(2014, April 25).The hypothesis was supported by this experiment because in the presence of the GFP gene the bacteria grew and glowed and bacteria that contain the GFP gene will survive and will also be able to grow and glow in the presence of ampicillin, due to the fact that the green fluorescence protein gene will resist the ampicillin; however if the sugar component is absent then, there will not be any glowing under the UV light.The hypothesis was supported by this experiment because in the presence of the GFP gene the bacteria grew and glowed.The Major findings: While the petri dish that did contain the +pGLO plasmid, and the GFP gene, they could not express the GFP gene because they did not grow in the presence of arabinose, due to...
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No matter what others think.Should an English teach say that if you want you can say the phrase “I brang my books to class.” instead of “I brought my books to class.”?I can teach that to my children at home.Should a teacher say that if you want you can believe a triangle has four sides or that 2+2=5?Abiogenesis is still merely a hypothesis and has not yet reached the status of a scientific theory such as evolution has.
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