Eukaryotic Theory

Eukaryotes are more closely related to Archaea. They both share certain structural similarites that are not seen in bacteria. These similarites include introns, histones, several types of RNA polymerase, and methionine as the first amino acid in protein synthesis. Also, the comparison of nucliec acid sequences shows greater similarity between archaea and eukaryotes. Other evidence shows that the enzymes involved in processes such as transcription and translation are more closely related to in Eukaryotes and Archaea compared to bacteria. In both archaea and eukayotes replication takes place in multiples origin of replication sites compared to that of bacteria which replication only takes place in one origin of replication site. All of this evidence

Prior to the development of DNA technology and the sequencing of organismal genomes, Charles Darwin suggested that the “tree” of life can be traced back to a single root (Koonin and Wolf, 2012). While Darwin’s theory was primitive, it laid the groundwork for the phylogenetic trees that are currently studied in science classrooms around the world. The three-domain tree, containing Eukarya, Archea, and Bacteria, soon became too simplistic due to the realization that some bacteria possessed the ability to exchange genetic information by horizontal gene transfer (Koonin and Wolf, 2012).

There are two main types of cells in the world. The simplest cells such as bacteria are known as Prokaryotic cells, and human cells are known as Eukaryotic cells. The main difference between each of these cells is that a eukaryotic cell has a nucleus and a membrane bound section in which the cell holds the main DNA which are building blocks of life.

Archaea and the origin of life. The word Archaea originated from the Greeks, meaning beginning. Throughout this essay we will go through discovers of Archaea and why they are classified as Prokaryotes and what the actual evolutionary relationship of Archaea to Eukaryotes and bacteria. We will look at the differing views throughout the scientific community in regards to the number of domains. Over whether three domains of life or two domains of life fit in the Tree of life. We will look at some research that has supportive evidence of the same. This essay will then look at the Habitat of Archaea – why many Archaea are classified as extremophiles and how these are not just bacteria’s and that extremophiles are a diverse group

While there are many different hypotheses to the evolution of eukaryotic organisms, two in particular have very plausible yet different approaches to this complex question. The Margulis hypothesis of the evolution of eukaryotic organisms focuses on the idea of endosymbiosis, which is the close interaction or association between different species with one of those species being inhabited within the other. Margulis hypothesized that free-living bacteria that were capable of energy production and photosynthesis where engulfed by a free-living cell. The cell and the bacteria now inside of it formed a mutualistic and symbiotic relationship with the bacteria providing the cell with the energy and food it needs while remaining protected inside the cell. Through evolutionary time this symbiotic relationship would grow so strong that the two individuals would not be able to function alone and thus the eukaryote would arise. The idea was supported by the fact that mitochondria and chloroplasts both have unique genomes that resemble the single circular chromosomes found within bacteria.

Subsequently,the relationship between prokaryotic cells and eukaryotic cells postulate the theory of endosymbiosis. Endosymbiosis incorporates the history of three individual prokaryotic cells, either able to convert energy , undergo aerobic respiration or participate in photosynthesis (Martin, Garg, & Zimorski, 2015). Eventually , the three individual skills are merged, forming a more complex cell. This theory suggests that independent prokaryotic cells later developed into plastids and mitochondria (Purdom, 2006) in eukaryotic

Kemaladewi D, Maino E, Hyatt E, Hou H, Ding M, Place K, Zhu X, Baghestani Z, Deshwar A, Merico D, Xiong H, Frey B, Wilson M, Ivakine E, Cohn R (2017) Correction of a splicing defect in a

The essence of life begins with knowing that all living things are made from cells. Cells and what is contained inside form the basic unit of structure and function in an organism. All cells have the same basic structure, the vital part being organelles. The name organelle comes from the Latin organellea; which means little organ. They can be found in both eukaryotic and prokaryotic cells and preform specific functions within that cell.

In the replication process of DNA, there are similarities between the process of replication of a Eukaryote cell and Prokaryote cell. There are also differences in both processes. The most notable difference would have to start with the cell themselves, which may add to additional differences in the processes. A prokaryote is a more simplistic cell with less DNA and a Eukaryote cell is much more complex with vast amounts of DNA.

It is a fact that 80 % of the earth’s history is solely a microbial life and continues to be a dominant life form. Living organisms can be grouped into three different domains: Archaea, Bacteria, and Eukarya. The differences between these three domains is concerned with rRNA, cell membrane lipid structure, and the sensibility to antibiotics. Prokaryotes includes members of bacteria and archaea while eukaryotes contain organisms that belong to the eukarya domain. For this compare and contrast we will only focus on two domains which are archaea and bacteria domains.

1.Cell theory just give a description of a cells. Like all living things are made up of cells individually. Also describes how cells can reproduce and metabolize by themselves; which means that they are living small organisms. Germ theory just clarifies on how these microbes are responsible for the infectious diseases that enter the body.

Interestingly, identical elements are also found to be part of A. Castellani genome suggesting a route for gene transfer either from prokaryotes via giant viruses or from protoeukaryotic ancestors [93]. These elements can manipulate the downstream gene expression [94] and play a major role in gene inactivation, deletion, duplication and genetic rearrangement in the genome via homologous/illegitimate recombination [34]. In an extreme case, about 30 non-autonomous transposable elements commonly known as MITEs (10 are integrated in the coding regions) have “colonized” [95] the genome of Pandoravirus salinus, but were undetectable in Pandoravirus dulcis [95]. Akin to their role in prokaryotes, they promote gene deletion and genetic rearrangement [96]. A conceivable outcome of such genome plasticity would be the loss and/or gain of function, accelerating host-switching and adaptation. Apart from these family-specific mobile elements, the genomes of NCLDV also contain self-splicing introns [97] and inteins along with HNH endonuclease which might aid in the mobility of genetic elements [98]. All three are known to influence genome evolution in all forms of life through their splicing and nuclease activity

Some the evidence for this theory include the mitochondria and plastids which can be identified in a eukaryot; however, prokaryotes originally also have the same functional capabilities as the mitochondria, as well as plastids. Perhaps the mitochondria’s development is simply a result of condensing the process of energy creation into a single organelle and the development of plastids was a result of prokaryotes also being capable of completing a similar task; however, felt the need for condensing this task into a single

However, due to their abundant added astronomically immense size, eukaryotes ' aggregate all-comprehensive biomass is estimated at about commensurable to that of prokaryotes. Eukaryotes aboriginal developed about 1.6–2.1 billion years ago.

The hypothesized steps for the evolution of eukaryotic cells from prokaryotic organisms involved mitochondria and plastids. Eukaryotic cells’ classical membrane- bound organelles evolved from the bacteria through a process called endosymbiosis, which ranks amongst the most important evolutionary events in history. In the early 1960s, Stanier, Douderoff, and Adelberg referred to the prokaryote–eukaryote divide as “the greatest single evolutionary discontinuity to be found in the present-day world” While chloroplasts organelles in a plant cell originated from cyanobacteria through endosymbiosis as well. Therefore, the process involved the following steps: The eukaryote mitochondrion evolved from a small autotrophic bacterium that was engulfed by a larger primitive, heterotrophic, eukaryotic cell