Serial Endosymbiosis Or Singular Event at the Origin of Eukaryotes?
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Buzzle – Zoology Terms – Glossary of Biology Terms and Definitions Http
Buzzle – Zoology Terms – Glossary of Biology Terms and Definitions http://www.buzzle.com/articles/biology-terms-glossary-of-biology-terms-and- definitions.html#ZoologyGlossary Biology is the branch of science concerned with the study of life: structure, growth, functioning and evolution of living things. This discipline of science comprises three sub-disciplines that are botany (study of plants), Zoology (study of animals) and Microbiology (study of microorganisms). This vast subject of science involves the usage of myriads of biology terms, which are essential to be comprehended correctly. People involved in the science field encounter innumerable jargons during their study, research or work. Moreover, since science is a part of everybody's life, it is something that is important to all individuals. A Abdomen: Abdomen in mammals is the portion of the body which is located below the rib cage, and in arthropods below the thorax. It is the cavity that contains stomach, intestines, etc. Abscission: Abscission is a process of shedding or separating part of an organism from the rest of it. Common examples are that of, plant parts like leaves, fruits, flowers and bark being separated from the plant. Accidental: Accidental refers to the occurrences or existence of all those species that would not be found in a particular region under normal circumstances. Acclimation: Acclimation refers to the morphological and/or physiological changes experienced by various organisms to adapt or accustom themselves to a new climate or environment. Active Transport: The movement of cellular substances like ions or molecules by traveling across the membrane, towards a higher level of concentration while consuming energy. -
Pinpointing the Origin of Mitochondria Zhang Wang Hanchuan, Hubei
Pinpointing the origin of mitochondria Zhang Wang Hanchuan, Hubei, China B.S., Wuhan University, 2009 A Dissertation presented to the Graduate Faculty of the University of Virginia in Candidacy for the Degree of Doctor of Philosophy Department of Biology University of Virginia August, 2014 ii Abstract The explosive growth of genomic data presents both opportunities and challenges for the study of evolutionary biology, ecology and diversity. Genome-scale phylogenetic analysis (known as phylogenomics) has demonstrated its power in resolving the evolutionary tree of life and deciphering various fascinating questions regarding the origin and evolution of earth’s contemporary organisms. One of the most fundamental events in the earth’s history of life regards the origin of mitochondria. Overwhelming evidence supports the endosymbiotic theory that mitochondria originated once from a free-living α-proteobacterium that was engulfed by its host probably 2 billion years ago. However, its exact position in the tree of life remains highly debated. In particular, systematic errors including sparse taxonomic sampling, high evolutionary rate and sequence composition bias have long plagued the mitochondrial phylogenetics. This dissertation employs an integrated phylogenomic approach toward pinpointing the origin of mitochondria. By strategically sequencing 18 phylogenetically novel α-proteobacterial genomes, using a set of “well-behaved” phylogenetic markers with lower evolutionary rates and less composition bias, and applying more realistic phylogenetic models that better account for the systematic errors, the presented phylogenomic study for the first time placed the mitochondria unequivocally within the Rickettsiales order of α- proteobacteria, as a sister clade to the Rickettsiaceae and Anaplasmataceae families, all subtended by the Holosporaceae family. -
The First Cells Were Most Likely Very Simple Prokaryotic Forms. Ra- Spirochetes
T HE O RIGIN OF E UKARYOTIC C ELLS The first cells were most likely very simple prokaryotic forms. Ra- spirochetes. Ingestion of prokaryotes that resembled present-day diometric dating indicates that the earth is 4 to 5 billion years old cyanobacteria could have led to the endosymbiotic development of and that prokaryotes may have arisen more than 3.5 billion years chloroplasts in plants. ago. Eukaryotes are thought to have first appeared about 1.5 billion Another hypothesis for the evolution of eukaryotic cells proposes years ago. that the prokaryotic cell membrane invaginated (folded inward) to en- The eukaryotic cell might have evolved when a large anaerobic close copies of its genetic material (figure 1b). This invagination re- (living without oxygen) amoeboid prokaryote ingested small aerobic (liv- sulted in the formation of several double-membrane-bound entities ing with oxygen) bacteria and stabilized them instead of digesting them. (organelles) in a single cell. These entities could then have evolved This idea is known as the endosymbiont hypothesis (figure 1a) and into the eukaryotic mitochondrion, nucleus, and chloroplasts. was first proposed by Lynn Margulis, a biologist at Boston Univer- Although the exact mechanism for the evolution of the eu- sity. (Symbiosis is an intimate association between two organisms karyotic cell will never be known with certainty, the emergence of of different species.) According to this hypothesis, the aerobic bac- the eukaryotic cell led to a dramatic increase in the complexity and teria developed into mitochondria, which are the sites of aerobic diversity of life-forms on the earth. At first, these newly formed eu- respiration and most energy conversion in eukaryotic cells. -
The Oxymonad Genome Displays Canonical Eukaryotic Complexity in the Absence of a Mitochondrion Anna Karnkowska,*,1,2 Sebastian C
The Oxymonad Genome Displays Canonical Eukaryotic Complexity in the Absence of a Mitochondrion Anna Karnkowska,*,1,2 Sebastian C. Treitli,1 Ondrej Brzon, 1 Lukas Novak,1 Vojtech Vacek,1 Petr Soukal,1 Lael D. Barlow,3 Emily K. Herman,3 Shweta V. Pipaliya,3 TomasPanek,4 David Zihala, 4 Romana Petrzelkova,4 Anzhelika Butenko,4 Laura Eme,5,6 Courtney W. Stairs,5,6 Andrew J. Roger,5 Marek Elias,4,7 Joel B. Dacks,3 and Vladimır Hampl*,1 1Department of Parasitology, BIOCEV, Faculty of Science, Charles University, Vestec, Czech Republic 2Department of Molecular Phylogenetics and Evolution, Faculty of Biology, Biological and Chemical Research Centre, University of Warsaw, Warsaw, Poland 3Division of Infectious Disease, Department of Medicine, University of Alberta, Edmonton, Canada 4Department of Biology and Ecology, Faculty of Science, University of Ostrava, Ostrava, Czech Republic Downloaded from https://academic.oup.com/mbe/article-abstract/36/10/2292/5525708 by guest on 13 January 2020 5Department of Biochemistry and Molecular Biology, Dalhousie University, Halifax, Canada 6Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden 7Institute of Environmental Technologies, Faculty of Science, University of Ostrava, Ostrava, Czech Republic *Corresponding authors: E-mails: [email protected]; [email protected]. Associate editor: Fabia Ursula Battistuzzi Abstract The discovery that the protist Monocercomonoides exilis completely lacks mitochondria demonstrates that these organ- elles are not absolutely essential to eukaryotic cells. However, the degree to which the metabolism and cellular systems of this organism have adapted to the loss of mitochondria is unknown. Here, we report an extensive analysis of the M. -
THE CASE AGAINST Marine Mammals in Captivity Authors: Naomi A
s l a m m a y t T i M S N v I i A e G t A n i p E S r a A C a C E H n T M i THE CASE AGAINST Marine Mammals in Captivity The Humane Society of the United State s/ World Society for the Protection of Animals 2009 1 1 1 2 0 A M , n o t s o g B r o . 1 a 0 s 2 u - e a t i p s u S w , t e e r t S h t u o S 9 8 THE CASE AGAINST Marine Mammals in Captivity Authors: Naomi A. Rose, E.C.M. Parsons, and Richard Farinato, 4th edition Editors: Naomi A. Rose and Debra Firmani, 4th edition ©2009 The Humane Society of the United States and the World Society for the Protection of Animals. All rights reserved. ©2008 The HSUS. All rights reserved. Printed on recycled paper, acid free and elemental chlorine free, with soy-based ink. Cover: ©iStockphoto.com/Ying Ying Wong Overview n the debate over marine mammals in captivity, the of the natural environment. The truth is that marine mammals have evolved physically and behaviorally to survive these rigors. public display industry maintains that marine mammal For example, nearly every kind of marine mammal, from sea lion Iexhibits serve a valuable conservation function, people to dolphin, travels large distances daily in a search for food. In learn important information from seeing live animals, and captivity, natural feeding and foraging patterns are completely lost. -
The Polyp and the Medusa Life on the Move
The Polyp and the Medusa Life on the Move Millions of years ago, unlikely pioneers sparked a revolution. Cnidarians set animal life in motion. So much of what we take for granted today began with Cnidarians. FROM SHAPE OF LIFE The Polyp and the Medusa Life on the Move Take a moment to follow these instructions: Raise your right hand in front of your eyes. Make a fist. Make the peace sign with your first and second fingers. Make a fist again. Open your hand. Read the next paragraph. What you just did was exhibit a trait we associate with all animals, a trait called, quite simply, movement. And not only did you just move your hand, but you moved it after passing the idea of movement through your brain and nerve cells to command the muscles in your hand to obey. To do this, your body needs muscles to move and nerves to transmit and coordinate movement, whether voluntary or involuntary. The bit of business involved in making fists and peace signs is pretty complex behavior, but it pales by comparison with the suites of thought and movement associated with throwing a curve ball, walking, swimming, dancing, breathing, landing an airplane, running down prey, or fleeing a predator. But whether by thought or instinct, you and all animals except sponges have the ability to move and to carry out complex sequences of movement called behavior. In fact, movement is such a basic part of being an animal that we tend to define animalness as having the ability to move and behave. -
Bioenergetics and Metabolism Mitochondria Chloroplasts
Bioenergetics and metabolism Mitochondria Chloroplasts Peroxisomes B. Balen Chemiosmosis common pathway of mitochondria, chloroplasts and prokaryotes to harness energy for biological purposes → chemiosmotic coupling – ATP synthesis (chemi) + membrane transport (osmosis) Prokaryotes – plasma membrane → ATP production Eukaryotes – plasma membrane → transport processes – membranes of cell compartments – energy-converting organelles → production of ATP • Mitochondria – fungi, animals, plants • Plastids (chloroplasts) – plants The essential requirements for chemiosmosis source of high-energy e- membrane with embedded proton pump and ATP synthase energy from sunlight or the pump harnesses the energy of e- transfer to pump H+→ oxidation of foodstuffs is proton gradient across the membrane used to create H+ gradient + across a membrane H gradient serves as an energy store that can be used to drive ATP synthesis Figures 14-1; 14-2 Molecular Biology of the Cell (© Garland Science 2008) Electron transport processes (A) mitochondrion converts energy from chemical fuels (B) chloroplast converts energy from sunlight → electron-motive force generated by the 2 photosystems enables the chloroplast to drive electron transfer from H2O to carbohydrate → chloroplast electron transfer is opposite of electron transfer in a mitochondrion Figure 14-3 Molecular Biology of the Cell (© Garland Science 2008) Carbohydrate molecules and O2 are products of the chloroplast and inputs for the mitochondrion Figure 2-41; 2-76 Molecular Biology of the Cell (© Garland -
Prokaryotic and Eukaryotic Organisms Pdf
Prokaryotic and eukaryotic organisms pdf Continue There are two types of cells: prokaryotic and eukaryotic. In this section, we will examine the similarities and differences between the two types. The objectives of the training to identify features common to all cells contrast the composition and size of prokaryotic and eukaryotic cells fall into one of two broad categories: prokaryotic and eukaryotic. Single-celled organisms of the domains Of Bacteria and Archaea are classified as prokaryotes (pro - before; carion - core). Animal cells, plant cells, fungi and proteanists are eukaryotes (eu - truth). Components of prokaryotic cells All cells have four common components: (1) plasma membrane, external coating separating the inner part of the cell from the environment; (2) cytoplasm, consisting of a jelly-like area inside the cell in which other cellular components are located; (3) DNA, the genetic material of the cell; and (4) ribosomes, particles that synthesize proteins. However, prokaryotes differ from eukaryotic cells in several ways. Figure 1. This image shows the generalized structure of the prokaryotic cell. A prokaryotic cell is a simple single-celled organism that lacks a nucleus or any other membrane organella. Soon we will see that this is significantly different in eukaryotes. Prokaryotic DNA is found in the central part of the cell: a darkened area called a nucleoid (Figure 1). Unlike archaea and eukaryote, bacteria have a cell wall of peptidoglycan consisting of sugars and amino acids, and many of them have a polysaccharide capsule (Figure 1). The cell wall acts as an additional layer of protection, helps the cell maintain its shape and prevents dehydration. -
Origin and Evolution of Plastids and Mitochondria : the Phylogenetic Diversity of Algae
Cah. Biol. Mar. (2001) 42 : 11-24 Origin and evolution of plastids and mitochondria : the phylogenetic diversity of algae Catherine BOYEN*, Marie-Pierre OUDOT and Susan LOISEAUX-DE GOER UMR 1931 CNRS-Goëmar, Station Biologique CNRS-INSU-Université Paris 6, Place Georges-Teissier, BP 74, F29682 Roscoff Cedex, France. *corresponding author Fax: 33 2 98 29 23 24 ; E-mail: [email protected] Abstract: This review presents an account of the current knowledge concerning the endosymbiotic origin of plastids and mitochondria. The importance of algae as providing a large reservoir of diversified evolutionary models is emphasized. Several reviews describing the plastidial and mitochondrial genome organization and gene content have been published recently. Therefore we provide a survey of the different approaches that are used to investigate the evolution of organellar genomes since the endosymbiotic events. The importance of integrating population genetics concepts to understand better the global evolution of the cytoplasmically inherited organelles is especially emphasized. Résumé : Cette revue fait le point des connaissances actuelles concernant l’origine endosymbiotique des plastes et des mito- chondries en insistant plus particulièrement sur les données portant sur les algues. Ces organismes représentent en effet des lignées eucaryotiques indépendantes très diverses, et constituent ainsi un abondant réservoir de modèles évolutifs. L’organisation et le contenu en gènes des génomes plastidiaux et mitochondriaux chez les eucaryotes ont été détaillés exhaustivement dans plusieurs revues récentes. Nous présentons donc une synthèse des différentes approches utilisées pour comprendre l’évolution de ces génomes organitiques depuis l’événement endosymbiotique. En particulier nous soulignons l’importance des concepts de la génétique des populations pour mieux comprendre l’évolution des génomes à transmission cytoplasmique dans la cellule eucaryote. -
Eukaryote Cell Biology - Michelle Gehringer
FUNDAMENTALS OF BIOCHEMISTRY, CELL BIOLOGY AND BIOPHYSICS – Vol. II - Eukaryote Cell Biology - Michelle Gehringer EUKARYOTE CELL BIOLOGY Michelle Gehringer Department of Biochemistry and Microbiology, University of Port Elizabeth, South Africa Keywords: cell theory, cell diversity, eukaryote cell structure, nucleus, chromatin, DNA, organelles, mitochondria, chloroplasts, transcription, RNA, translation, ribosomes, cell cycle, interphase, mitosis, meiosis, signal transduction, growth regulation, cancer, oncogenesis. Contents 1. Introduction 1.1. The first cell 2. Origin of Eukaryotes 3. Cellular differentiation in multicellular organisms 3.1. Plants 3.2. Animals 4. Eukaryotic cell structure 5. Organization of eukaryotic cells 5.1. Plasma membrane 5.2. Extracellular matrices 5.3. Protein synthesis and transport 5.4. Cytoskeleton and movement 5.5. Nucleus 5.5.1 Genomes 5.5.2 Gene expression 5.5.3 Maintaining the genome 5.6. Organelles 6. The cell cycle 6.1. Mitosis 6.2. Meiosis 7. Regulation of cell growth 7.1. Signal transduction 7.2. Programmed cell death 7.3. CancerUNESCO – EOLSS 8. Experimental Models 8.1. Yeast SAMPLE CHAPTERS 8.2. Arabidopsis 8.3. Drosophila 8.4. The mouse 8.5. Cell culture 8.6. Separation of cellular contents 8.7. Tracing biochemical pathways 9. Future Investigations Glossary Bibliography ©Encyclopedia of Life Support Systems (EOLSS) FUNDAMENTALS OF BIOCHEMISTRY, CELL BIOLOGY AND BIOPHYSICS – Vol. II - Eukaryote Cell Biology - Michelle Gehringer Biographical Sketch Summary Cells form the basic unit of life on our planet. They are well organized systems which perform all the essential tasks of eating, respiring, replicating and excreting waste products. The first cells, which are thought to have evolved about 3.8 billion years ago, much resembled present day prokaryotes. -
Localization of the Mitochondrial Ftsz Protein in a Dividing Mitochondrion Mitochondria Are Ubiquitous Organelles That Play Crit
C2001 The Japan Mendel Society Cytologia 66: 421-425, 2001 Localization of the Mitochondrial FtsZ Protein in a Dividing Mitochondrion Manabu Takahara*, Haruko Kuroiwa, Shin-ya Miyagishima, Toshiyuki Mori and Tsuneyoshi Kuroiwa Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Tokyo 113-0033, Japan Accepted November 2, 2001 Summary FtsZ protein is essential for bacterial cell division, and is also involved in plastid and mitochondrial division. However, little is known of the function of FtsZ in the mitochondrial division process. Here, using electron microscopy, we revealed that the mitochondrial FtsZ (CmFtsZ 1) local- izes at the constricted isthmus of a dividing mitochondrion on the inner (matrix-side) surface of the mitochondrion. These results strongly suggest that the mitochondrial FtsZ acts as a ring structure on the inner surface of mitochondria. Key words Cyanidionschyzon merolae, FtsZ, FtsZ ring, mitochondria, mitochondrion-dividing ring (MD ring) . Mitochondria are ubiquitous organelles that play critical roles in respiration and ATP synthesis in almost all eukaryotic cells. Mitochondria are thought to have originated from a-proteobacteria through an endosymbiont event. Like bacteria, they multiply by the binary fission of pre-existing mitochondria. Although the role of mitochondria in respiration and ATP production is well under- stood, little is known about the proliferation of mitochondria in cells. In plastids, which also arose from prokaryotic endosymbionts, the ring structure that appears at the constricted isthmus of a dividing plastid (the plastid-dividing ring or PD ring) has been iden- tified as the plastid division apparatus (Mita et al. 1986). The PD ring is widespread among plants and algae, and consists of an outer (cytosolic) ring and an inner (stromal) ring in most species. -
Novel Lineages of Oxymonad Flagellates from the Termite Porotermes Adamsoni (Stolotermitidae): the Genera Oxynympha and Termitim
Protist, Vol. 170, 125683, December 2019 http://www.elsevier.de/protis Published online date 21 October 2019 ORIGINAL PAPER Novel Lineages of Oxymonad Flagellates from the Termite Porotermes adamsoni (Stolotermitidae): the Genera Oxynympha and Termitimonas a,1 b a c b,1 Renate Radek , Katja Meuser , Samet Altinay , Nathan Lo , and Andreas Brune a Evolutionary Biology, Institute for Biology/Zoology, Freie Universität Berlin, 14195 Berlin, Germany b Research Group Insect Gut Microbiology and Symbiosis, Max Planck Institute for Terrestrial Microbiology, 35043 Marburg, Germany c School of Life and Environmental Sciences, The University of Sydney, Sydney, NSW 2006, Australia Submitted January 21, 2019; Accepted October 9, 2019 Monitoring Editor: Alastair Simpson The symbiotic gut flagellates of lower termites form host-specific consortia composed of Parabasalia and Oxymonadida. The analysis of their coevolution with termites is hampered by a lack of informa- tion, particularly on the flagellates colonizing the basal host lineages. To date, there are no reports on the presence of oxymonads in termites of the family Stolotermitidae. We discovered three novel, deep-branching lineages of oxymonads in a member of this family, the damp-wood termite Porotermes adamsoni. One tiny species (6–10 m), Termitimonas travisi, morphologically resembles members of the genus Monocercomonoides, but its SSU rRNA genes are highly dissimilar to recently published sequences of Polymastigidae from cockroaches and vertebrates. A second small species (9–13 m), Oxynympha loricata, has a slight phylogenetic affinity to members of the Saccinobaculidae, which are found exclusively in wood-feeding cockroaches of the genus Cryptocercus, the closest relatives of termites, but shows a combination of morphological features that is unprecedented in any oxymonad family.