Archaea, they are prokaryotic organisms with single cell absence of a defined nucleus which has characteristic recognizably different in nature which separates them from bacteria a prokaryote, as well as from eukaryotes (Niederberger, 2017).
At 6.7km depth inside the earth’s crust, pressures up to 110Mpa; more than 10km deep inside the ocean micro organisms are found. From extreme pH 0 to extreme basic pH 12.8; and from the hydrothermal vents at 122°C to the frozen sea water -20°C (Rampelotto, 2010).Archaea consist of various extreme environments. The habitats that allow them to survive in extreme limit are temperature, Ph, Salinity and anaerobiosis which are supposed to be the homes to hyperthermophiles, extreme acidophiles, extreme halophiles and methanogens. Archers are isolated from typical environments such as hot springs, hydrothermal vents, solfataras, salt lakes, soda lakes, sewage digesters and rumen (Chaban, no date).
Archaea were observed as stable, but varied according to temperature (De Leon, no date).Archaes are highly diverse. They are adapted live at high salt concentrations.(Ma, 2010).On the other hand, the archaea presented in active sludge is shown by the fluorescence in situ hybridization (Fredriksson, 2012).
Hydrothermal vents, the strains of archaea and bacteria were observed in specific hydrothermal region, some of the archaeal strains were spreaded and they appear as spreaded over a wide area and settle among and establish control over new niches very efficiently. Further of great temperature fluid sample in pairing up with other types point that strains that are less in some niches are present in large amount in others (Anderson, 2015).All methane produced excluding the industry, is produced by the methanogenic archaea. Archaea belongs to group of micro organisms which are ancient that occupy ecological niches with concentrations of oxygen limited such as wetlands. As an important source of methane termites have been recognized. The production of methane and methanogens present has Benn systematically screened in a large variety of invertebrate taxa, the results obtained show the characteristic property are likely that of the host taxon and production of methane (sustr, 2014).
Archaea which produces methane increase rapidly in number and multiply in natural anaerobic ecosystems anaerobic biological systems. Where the outward feature of electron acceptors other than that of carbon dioxide remain limited. Methanogens interact with anaerobic syntrophs which converts hydrogen, formate and acetate, which are obtained from the breakdown of the complex organic matter into methane and carbon dioxide (Narihiro, 2009).Methanogens are being found to the rumen in cattle and other ruminants. Methanogens are present in the intestine of humans. Presumbly increase rate of the digestion and its flow through the gastrointestinal tract, the time is limited which is available for the production of methane within the rumen (Hook,2010).Extreme thermophiles :- Physical and chemical condition in many terrestrial environment can be defined extreme from an anthropometric perspective. Organisms which are able to develop in such extreme environments are called extremophiles.
Extreme condiments like high temperatures of warm permanent environments such as hydrothermal vents, volcanic areas, hot springs are relatively common. The organisms which grow at relatively high temperature are known as thermophiles where it grow at an optimum temperature within 50-80°C, Organisms that grow above 80°C are known as hyperthermophiles (stable) (Maugini, 2009).These micro organisms are adapted in such a way to growth by sulfur-H, respiration of inorganic carbon and nitrogen fixation (Frock, 2012).Extreme halophiles :- Halophilic archaea survive in high salt contraction environments because they maintain intracellular salt concentration close to saturation in which their cellular processes have been adapted to the functions toward these conditions. Salt concentration can effect the DNA binding in high salt.
Halophiles some live in Dead Sea which is an extremely hypersaline environment, consist of high concentration for about 340% where salt is dissolved totally with ions like magnesium and calcium being higher than that of monovalent ions (Nazerath, 2012). Halobacterium salinarum belongs to the archaeal domain of life. Halophiles are bioenergitically flexible where it can perform both respiration and photosynthesisu and they obtain energy using fermentation (Gonzalez, 2009). ?Task 2Mitochondrial biogenesis make effective use of complex protienaceous machinery in which to import pre proteins synthesized cytosolically. Three multi subunit large protein complexes are found one in the outer membrane whereas two of them in the inner membrane were establishes.
By the cooperation of translocation complexes with the soluble proteins from the cytosol, the inter membrane space and the matrix. Through the outer membrane Chanel the translocation of pre sequence containing pre proteins comprise the charged mitochondrial targeting sequence containing a chain of imported components of successive electrostatic interactions. Translocation across the inner mitochondrial membrane make effective use of the energy from the proton motive force of the inner membrane and hydrolysis of ATP. ATP- dependent import motor formed by the matrix chaperone system of the mitochondrial heat shock protein 70 by interaction with the polypeptide chain in the carrying of materials and components of the inner membrane translocase. The interaction between the integral inner membrane proteins that of the metabolic carrier family and the imported components which are newly identified of the inter membrane space, in which are inserted into the inner membrane by a second translocase complex (voos, 1999).Mitochondrial disorders :- In the past ten years large amount of information were concerned regarding the inherited mitochondrial disorders. In which the molecular genetics and various mutations were established and understood. Nevertheless, this enlargement must be related on the documentation supplied by pathological studies with identification of morphological abnormal feature, like tubular cristae present in the affected mitochondria (Robert and Thum, 2013).
Kearn-sayre syndrome ( mitochondrial cytopathy) :-Kearn sayre is a syndrome in which a pigmentary retinopathy is related with cardiomyopathy and cause weakness in extraocular muscles. Abnormal feature in mitochondria morphology differ in size and shape and the existence of Paracrystal line includes in ultra structural level and subsarcolemall accumulations of mitochondria which shows abnormality under the light microscope level. The photoreceptors present cause thinning, large mitochondria are recognized at the retinal pigment epithelium. The syndromes that lies over the kearns sayre syndrome are; MELAS consist of mitochondrial encephalopathy, lactic acidosis, and stroke where as MERRF spectrum consist of myoclonus, epilepsy, and red fibers which are ragged (Roberts and Thum, 2013).?Task 3To form the next generation two gametes combine with their genome, which is called sexual reproduction.
The copy number of genome has to be reduced by half before gamers are formed on the next round. This reduction in the number of sets of chromosome in a cell in which successfully bring out by an commonly occurring cell division called meiosis (Hochwagen,2008). Meiosis, a nuclear division is where the umber of chromosome is divided into half from the diploid number (2n) to the haploid number (n).
Same like mitosis, meiosis also consist DNA replication in the parent cell during the interphase. Nuclear division and cell division contain two cycles, they are known as Meiosis I and meiosis II. During meiosis a single diploid divides to form four haploid cells, happen during the formation of sperm and eggs (gametogenesi) in animals and in plants occur during the spore formation. Meiosis is a process which occurs continuously divided into stages like prophase, metaphase, anaphase and telophase.
All these four stages takes place in both meiosis I and II again. During meiosis I, prophase are usually divides in 4 stages : (i) Early prophase I (chromosomes become short and visible), (ii) prophase I (A process called synopsis in which identical chromosomes pair up in which one from male parent and the other from female parent Chromosome and centromere are visible here). (iii) in this stage crossing over occurs (The identical chromosomes repel each other and slightly separate. This stage is known as crossing over phase is which at points the two chromosomes join moving in a constant direction in their length, these joining points are known as chiasmata. (iv) The homologous chromosome repel each other continuously and they get into shapes determined by the number of chiasmata. Metaphase I, the homologous chromosomes arrange themselves in the spindle which is attached by their centromere.
Anaphase I, chromosomes they move towards the opposite poles. Telophase I, the homologous chromosome arrives to the end. Even though the chromosomes are divided into half the two chromatids will remain present.
Interphase II, this stage occurs in animal cells usually. Meiosis II this is identical to mitosis. Prophase III shows absence if interphase II is been absent. The nucleoli and nuclear envelope are distributed, where the chromatids get thicker and short, appearance of spindle fibre is seen.
Metaphase II, lining up of chromosomes along the equator of the cell. Anaphase II, division of centromeres happen, the chromatids reach to the opposite poles by the pull of spindle fibers. Telophase II, form four haploid daughter cell reformation of nuclear envelope take place (Thorpe, 2009).Crossing over, in many places identical chromosomes exchange parts of their chromosome with each other. This is known as crossing over and the location of crossing over referred as chiasma.
The genetic material get exchanged and genetically recombine, form genes mixed from two chromosomes (Wilson, 2009).Exchanging of the genetic material between the maternal and paternal chromosomes are known as crossing over during meiosis, is strictly controlled to limit the number of crossovers in every chromosome pair (Jones, 2006).Each of human chromosome they undergo 3 crossing over procedure. The recombination produce varieties in large amount, since any place through the chromosome crossing over can take place.
Random fertilization, each of the human partner achieve one of 8 million combinations of the paternal and the maternal chromosomes. Trillions and millions of genetic consequences are possible like a random sperm fertilizing a random ovum. The genetic variation leads to difference in one another, for example siblings differ from each other. All of this variety is very important for the evolution variation which are favorable and the gene combination will gather throughout natural selection. The diversity produced via sexual reproduction make sure the genetic variation within population make adjustments to make change in the environments. Genetic variation occur due to mutation, sexual reproduction remain advantageous due to the way how mixing and matching happens (Wilson, 2009).?Task 4Apoptosis or programmed cell death a necessary constituent in number of processes such as the normal cell turnover, development of the immune system, hormone dependent atrophy, embryonic development and chemical induced cel, death, apoptosis occur as a stable mechanism in maintaining dells population in tissues during development and increase of age (Elmore, 2007).Apoptosis give rise to two different pathways they are extrinsic and intrinsic pathways.
The extrinsic pathway is briefly explained in figure 1.2, this begins in response to the extracellular signals at the cell surface. The apoptosis information from cells is passed to a cytosolic part which are activated in a clarified order. The receptor which participated in this pathway is known as the death receptor, these receptors belong to protein family known as the Tumor necrosis factor receptors. The receptors from into a protein in which is made up of three identical polypeptide which binds to the extracellular death ligands cluster, where death domain is exposed in each receptor on its cytosolic part by changing their shape.
Binding of death to an adapter protein happens like the interaction between SH2 with the phosphotyrosines along with proline rich sites in some other proteins. By a death effector domain the adaptor proteins bind to protease. Fas was the first death Logan to be discovered, most of the death receptors in which the adaptor protein binds to death domain is called the fas-associated protein with death domain (FADD) as this is the reason. Once they are bounded to the receptors, FADDS they enlist protease series which begins to digest the cell interior (Plopper, 2014).Caspases are effectors of extrinsic and intrinsic pathways, in which their activities are regulates.
Interaction between the inhibitor of apoptosis protein family and capsases decrease their proteolytic activity (Gilfillan, 2011).Intrinsic pathway is initiated at the mitochondrial outer membrane, in which it is triggered along intracellular signals that communicates information about the condition of the cell. The causes that make intrinsic signals to exist are severe DNA damage, oxygen radicals, disruption in membrane or due to the toxic an harmful substances that have perforated the plasma membrane. The transcription of gene which belongs to the bcI -2-family of proteins get triggered due to this. The relationship between the real triggers and transcription is not understandable but several observations have concluded that during apoptosis activation the host of regulatory proteins control it.
DNA damage triggers intrinsic pathway, the resolution to stop the cell cycle and DNA repairing or to conduct apoptosis these depends on stabilizing carefully between both the pro and anti apoptosis signals. The MRN complex recognizes the interruption in DNA and they enlist proteins to fix up the damaged DNA. Toward the MRN the transcription factors such as p53 and E2F they guide the gene expression which is required to perform the damage of the DNA. Transcription factors like p53 and E2F and other factors can begin apoptosis by apoptosis gene expression comparatively than that of DNA repair genes (plopper ,2014).Figure 1.
2 The extrinsic and intrinsic pathways are summarized on the above diagram P53 is an important gene in pathways of apoptosis. This p53 gene in induced during cellular stress, via depolarization of the mitochondria and modification of the cells and to the inducers of apoptosis. P53 controls and maintains the pathways of apoptosis by regulating the gene expression which participated in the modification of mitochondrial permeability or else through sensitizing cells to the apoptosis by increase the of thecellular death receptors expression, namely Fas and killer/ DRS.
P53 they act as cellular gatekeeper, where it observed cellular stress always (McLendon, 2006).
