...These similarities led to what is known today as the endosymbiotic theory. The endosymbiotic theory states that some organelles, such as mitochondria and chloroplasts, evolved through symbiotic relationships. Over the years, there have been many discoveries made to support this theory. The strongest evidence to date that has been found to support this theory is mitochondria and chloroplasts contain their own DNA. This could suggest that at one point in time, they lived on their own as prokaryotes. Furthermore, since mitochondria and chloroplasts both contain small amounts of genetic information, they must have been free living organisms at one point. In addition, they are capable of synthesizing their own proteins, which is something all organisms can do. As a result of these observations and many more that were made throughout time, scientists were able to provide much support for the endosymbiotic...
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...glucose, producing carbon dioxide and water in the process. The chloroplast consumes water and carbon dioxide as it captures energy from light and funnels it into the chemical energy of glucose, releasing oxygen in the process. Endosymbiotic theory proposes that these organelles were once prokaryotic cells, living inside larger host cells. The prokaryotes may initially have been parasites or even an intended meal for the larger cell, somehow escaping digestion. Whatever the cause of their initial internment, these prokaryotes might soon have become willing prisoners to a grateful warden. The prisoner prokaryotes might have provided crucial nutrients (in the case of the primitive chloroplast) or helped to exploit oxygen for extracting energy (in the case of the primitive mitochondrion). The prokaryotes, in turn, would have received protection and a steady environment in which to live. Multiple lines of evidence support the endosymbiotic theory. Endosymbiosis is observed elsewhere in biology. Mitochondria and chloroplasts have intriguing similarities in structure, reproduction, biochemistry, and genetic makeup to certain prokaryotes. The plain fact that mitochondria and chloroplasts have any genetic information of their own argues in favour of the theory. Because virtually all eukaryotes have some sort of mitochondria, while only photosynthetic eukaryotes have chloroplasts, it has been proposed that endosymbiosis occurred twice, in series. First, an aerobic (oxygen-using) heterotrophic...
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...Biology Semester 1 Research Project Cellular Process Meagan Baggett 4th Period The endosymbiotic theory explains how eukaryotic cells may have evolved from prokaryotic cells. Symbiosis is a close relationship between two different organisms. The discovery of the endosymbiotic theory took hundreds of years to be considered as real and was eventually it was finalized. The endosymbiotic theory is believed to be first introduced and described by Andreas Schimper in 1883. Schimper was a German botanist and phytogeographer. He was born on May 12, 1856 and he passed away on September 9, 1901, at the age of forty-five. After studying at the University of Strassburg from 1874 to 1878, in the process acquiring his Ph.D, He left Germany...
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...himself immediately after. This dilutes the strength of the paper. He makes reference to himself three times at the end of the paper. He does not make reference to Brandenburger & Nalebuff, who are very well respected academics and are considered the gurus on the concept of Coopetition. The way the paper has been quoted shows that either Zineldin thinks he is better than Brandenburger & Nalebuff or he is not scholarly aware of the depth of work that they have contributed to the subject. Zineldin makes a fundamental mistake when quoting Margulis by using a ‘he’ reference, yet Margulis is a female. This may demonstrate that Zineldin has not researched thoroughly. However, Margulis’ work on Serial Endosymbiosis Theory correlates with Zineldin’s view on Coopetition theory. Zineldin states seven preconditions for the development of enduring and mutually beneficial coopetitive relationships. I believe the criteria set by Zineldin (2004) are only applicable in a utopian business set up. However, not to totally dismiss the criteria, I think...
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...The theory of Endosymbiosis explains the origin of chloroplasts and mitochondria and their double membranes. This concept assumes that chloroplasts and mitochondria are the result of years of evolution initiated by the endocytosis of bacteria and blue-green algae. According to this theory, blue green algae and bacteria were not digested; they became symbiotic instead. Endocytosis is when a substance gains entry into a cell without passing through its cell membrane. A cell's plasma membrane encloses and fuses to lock foreign material inside. An intracellular vesicle is formed as result .The ribosomes of the inner structure in chloroplasts and mitochondria resemble prokaryotic ribosomes. Evolutionist Lynn Margulis proposed the idea in the late 1960’s. In 1970 she published her argument in The Origin of Eukaryotic Cells. The controversy surrounding theory is that it is not a fact. The endosymbiotic theory is that it proposes no real process and most textbooks show the simple picture of a cell that swallows another cell that becomes a mitochondrion. There is a difference between the process of endosymbiosis and its incorporation in the germ line, necessitating genetic changes. One of the controversies stated by Albert de Roos: What were those changes? What was the host? Was it a fusion, was it engulfment, how did the mitochondrion get its second membrane, how did two genomes in one cell integrate and coordinate? The theory is also strongly teleological, illustrated by the widely...
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...1 2 Contact Information Dr. Sonish Azam Office: SP 375.23 Tel: 514-848-2424 ex 3488 Email: sonish.azam@concordia.ca (Please mention BIOL 266 in subject) Office hours: after the class or by appointment Topics 3 ! ! ! ! ! ! Topics !"#$%&!"&'(&%")(*(+& %,--.&/01&"23/0,--,.&& '4567,846/-&*,/69450.:&*,.;42/9450&,0,.&/01&%72585.58,.&& ?,8@2/0,&;259,40.&/01&.92A69A2,& ?,8@2/0,&92/0.;529& #259,40&.529403&95&523/0,--,.& >,0,2/-&;24064;-,.&5B&6,--&.430/-403& C430/-&92/0.1A69450&;/97D/=.& %=95.E,-,950& ?495.4.&/01&%=95E40,.4.& !7,&A04F,2./-&6,--&6=6-,&650925-&.=.9,8! %,--&6=6-,&67,6E&;5409.& %/06,2&/01&G;5;95.4.& 3. Objectives 1. Learn about structural features and functions of the components in an Textbooks 4 (1) Essential Cell Biology by Alberts et al. (4th Edition) published by Garland Publishing, Inc. in 2014. (2) Cell and Molecular Biology: Concepts and Experiments by Gerald Karp (7th Edition) published by John Wiley & Sons, Inc. in 2013. • The textbooks are recommended, neither of them is required. • Additional reading will be posted on moodle website and announced in class Internet address: http://moodle.concordia.ca Grading Scheme 5 • Midterm • In-class Activity/Assignment • i>clicker • Final exam 30% 12% 3% (starts Jan 20th) 55% Final exam will cover the entire course (cumulative) 6 CELLS AND ORGANELLES Lecture 1 BIOL 266/4 2014-15 Dr. S. Azam Biology Department Concordia University What does it mean to...
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...Milky Way Galaxy, the Sol System, 4.2 billion years ago, rock and ice particles swirling around a very young sun collide and merge, producing large planetoids. One of them, an infant planet we have come to call home, is born. This planet will later be named Earth. At this point the baby Earth is nothing more than a scorching inferno of magma and vaporized rock, spitting up nothing more than magma volcanoes. This infant planet is very different from the one we know today. Its atmosphere is comprised of deadly gasses and probably had a sky the color of a pinkish-orange. Its oceans containing large quantities of dissolved iron were most likely a kind of brown color. Life on early Earth began with very little amounts of oxygen compared to the quantities we have today, it was comprised of primitive elements and very slowly evolved into the Earth we know today. Had you been on Earth all that time ago, when it was just beginning to evolve, you would have died with just a few deep breaths! Earth’s early atmosphere contained little or no oxygen. It was primarily comprised of carbon dioxide, water vapor, and nitrogen, with smaller amounts of carbon monoxide, hydrogen sulfide, and hydrogen cyanide. Over time a controversial question emerged, could organic molecules assemble under the conditions on early Earth? In 1953, biochemists Stanley L. Miller and Harold C. Urey conducted an experiment to find these answers; they tested for what kind of environment would be needed to allow life to...
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...Chloroplast and Mitochondrion in Plant Cells Introduction: Mitochondrion and chloroplast are two organelles that are very important to organisms. Both provide energy and nourishment to the cell. While chloroplast is found in plant cells only, mitochondrion is found in both animal and plant cells. It is believed that these two organelles were once bacterial cells on their own, but then they were engulfed by other bacteria. This theory is called the Endosymbiotic Theory. This theory is proven by the fact that chloroplast and mitochondrion are the only organelles, within a cell, that have their own DNA. They also use this DNA to produce their own enzymes and proteins. Further proof is shown by the fact that both these organelles have a double layer of membrane surrounding them, and that they replicate as a bacteria does. Purpose: * Prepare a supernatant of spinach leaf * Demonstrate proper techniques involved in using centrifuge * Using filtration and centrifugation, separate the chloroplast from other organelles in a spinach leaf * Identify mitochondrion in an onion cell Materials: * Fresh spinach leaves * Grinding solution * 0.33 M sorbitol * 10mM sodium pyrophosphate (NaPO) * 4mMMgCl * 2mM Ascorbic Acid * Adjust pH to 6.5 with HCl * Chopping board and knife * Chilled mortar and pestle * Cheesecloth * Refrigerated preparative centrifuge * Suspension solution * 0.33 M Sorbitol * 2mMEDTA ...
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...Prokaryotes and Eukaryotes cell Cell theory states that all organisms are made of one or more cells. There are two basis types of cell: prokaryotes, which do not contain a nucleus, and eukaryotes, which have a true nucleus. The difference between the structure and functioning of prokaryotes and eukaryotes is so great that it is considered, by some, to be the most important distinction among groups of organisms. However, if we are to believe the endosymbiosis theory and that eukaryotes evolved from prokaryotes there must also be some fundamental similarities. A significant similarity is the fact that both prokaryotes and eukaryotes use the same genetic material (DNA) and genetic code to store and translate genetic information. But this genetic information is arranged very differently within the two types of cell. In eukaryotes the DNA is packed into chromatins and sequestered within a double membrane bound organelle, known as the nucleus, and is easily seen using a microscope. On the other hand, prokaryotes lack this distinct nucleus and nucleur membrane but instead have a nucleoid, which is an irregularly shaped region within the cell where the genetic information is localised in the form of a, usually circular, double strand of DNA. Prokaryotes and some eukaryotes are also known to have additional small satellite structures of DNA called plasmids. Both prokaryotes and eukaryotes also contain ribosomes which are the organelles responsible for accurately translating this...
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...Naturwissenschaften (2004) 91:255–276 DOI 10.1007/s00114-004-0515-y REVIEW Ulrich Kutschera · Karl J. Niklas The modern theory of biological evolution: an expanded synthesis Published online: 17 March 2004 Springer-Verlag 2004 Abstract In 1858, two naturalists, Charles Darwin and Alfred Russel Wallace, independently proposed natural selection as the basic mechanism responsible for the origin of new phenotypic variants and, ultimately, new species. A large body of evidence for this hypothesis was published in Darwin’s Origin of Species one year later, the appearance of which provoked other leading scientists like August Weismann to adopt and amplify Darwin’s perspective. Weismann’s neo-Darwinian theory of evolution was further elaborated, most notably in a series of books by Theodosius Dobzhansky, Ernst Mayr, Julian Huxley and others. In this article we first summarize the history of life on Earth and provide recent evidence demonstrating that Darwin’s dilemma (the apparent missing Precambrian record of life) has been resolved. Next, the historical development and structure of the “modern synthesis” is described within the context of the following topics: paleobiology and rates of evolution, mass extinctions and species selection, macroevolution and punctuated equilibrium, sexual reproduction and recombination, sexual selection and altruism, endosymbiosis and eukaryotic cell evolution, evolutionary developmental biology, phenotypic plasticity, epigenetic inheritance and...
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...Growth Curve: Lag Phase Intense activity preparing for population growth, but no increase in population. Log Phase Logarithmic, or exponential, increase in population. Stationary Phase Period of equilibrium; microbial deaths balance production of new cells. Death Phase Population Is decreasing at a logarithmic rate. Prokaryotes (Bacteria) Gram Positive Low G + C Firmicutes 1. Clostridium: enospore-producing (obligate anaerobes) 2. Bacillales: a. Bacillus – rod-shapes, makes endospre, aerobic and facultative anaerobe b. Straphyloccus- clusters of cocci (MRSA) 3. Lactobacillales- aerotolerant anaerobes c. Lactrobacillus d. Streptococcus e. Enteroccus f. Listeria 4. Mycoplasmatales- lack a cell wall, small size, takes lots of shapes g. M. pneumoniae- walking pneumonia High G + C Actinobacteria 1. Bacteria that formed filaments a. No conidiospores b. Form conidiospore i. Actinomyces- Anaerobic ii. Streptocytes-Aerobic 2. Don’t form filaments c. Mycobacterium- acid-fast cell wall d. Carynebacterum- causes diptheria e. Propionibacterium- causes acne f. Gardnarella- stains gram-neg- causes bacterial vaginosis Gram Negative (proteobacteria-“many shapes”, all are chemoheterotropic (energy from chemicals, carbon from organic molecules) Alphaproteobacteria: Obligate intracellular parasite 1. Rickettsia: arthrod-borne...
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...CHAPTER 6 POPULATION GENETICS SELECTION 1. Which of the following options factually completes the statement, "If a population is in Hardy-Weinberg equilibrium..."? a. There can be no more than two alleles. b. The two alleles will be present at equal frequency. c. Allele frequencies will not change from one generation to the next. d. The dominant allele will be more common. |Correct Answer: |C, Allele frequencies will not change from one generation to the next. | [pic] 2. If allele frequencies do not change from one generation to the next, is the population definitely in Hardy-Weinberg equilibrium? Why or why not? No, it might not be in Hardy-Weinberg equilibrium. Any process that selectively targets heterozygotes can affect genotype frequencies without necessarily changing allele frequencies in the next generation. Examples are nonrandom mating, overdominance, and underdominance. [pic] 3. The Hardy-Weinberg equilibrium principle yields which of the following conclusions? a. If the allele frequencies in a population are given by p and q, the genotype frequencies are given by p2, 2 pq and q2. b. The allele frequencies in a population will not change over time. c. If the allele frequencies in a population are given by p and q, the genotype frequencies are given by p2 and q2. d. The first and third answers are correct. e. The first and second choices are correct. |Correct Answer:...
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...chapter introduces the topics of microscopy and cell fractionation, followed by a review of the cell and the major organelles and structures of eukaryotic cells. A challenge with this chapter is to keep this data from simply being a list of parts. In addition to the structure and function of individual organelles, questions probe student understanding of the cell as a dynamic, interconnected system: the flow of membrane and proteins in the endomembrane system to the plasma membrane; the flow of information from the nucleus to the cytoplasm; and the connection between the cytoskeleton, the plasma membrane, and the extracellular matrix. An evolutionary perspective goes beyond structural distinctions between prokaryotes and eukaryotes to examine theories concerning the evolutionary origins of eukaryotes and key eukaryotic cell structures. Multiple-Choice Questions 1) When biologists wish to study the internal ultrastructure of cells, they can achieve the finest resolution by using A) a phase-contrast light microscope. B) a scanning electron microscope. C) a transmission electronic microscope. D) a confocal fluorescence microscope. E) a super-resolution fluorescence microscope. Answer: C Topic: Concept 6.1 Skill: Knowledge/Comprehension 2) The advantage of light microscopy over electron microscopy is that A) light microscopy provides for higher magnification than electron microscopy. B) light microscopy provides for higher resolving power than electron microscopy. ...
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...Biology guide First assessment 2016 Biology guide First assessment 2016 Diploma Programme Biology guide Published February 2014 Published on behalf of the International Baccalaureate Organization, a not-for-profit educational foundation of 15 Route des Morillons, 1218 Le Grand-Saconnex, Geneva, Switzerland by the International Baccalaureate Organization (UK) Ltd Peterson House, Malthouse Avenue, Cardiff Gate Cardiff, Wales CF23 8GL United Kingdom Website: www.ibo.org © International Baccalaureate Organization 2014 The International Baccalaureate Organization (known as the IB) offers four high-quality and challenging educational programmes for a worldwide community of schools, aiming to create a better, more peaceful world. This publication is one of a range of materials produced to support these programmes. The IB may use a variety of sources in its work and checks information to verify accuracy and authenticity, particularly when using community-based knowledge sources such as Wikipedia. The IB respects the principles of intellectual property and makes strenuous efforts to identify and obtain permission before publication from rights holders of all copyright material used. The IB is grateful for permissions received for material used in this publication and will be pleased to correct any errors or omissions at the earliest opportunity. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted...
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...CARIBBEAN EXAMINATIONS COUNCIL Caribbean Advanced Proficiency Examination CAPE ® BIOLOGY SYLLABUS Effective for examinations from May/June 2008 CXC A10/U2/07 Published by the Caribbean Examinations Council All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form, or by any means electronic, photocopying, recording or otherwise without prior permission of the author or publisher. Correspondence related to the syllabus should be addressed to: The Pro-Registrar Caribbean Examinations Council Caenwood Centre 37 Arnold Road, Kingston 5, Jamaica, W.I. Telephone: (876) 630-5200 Facsimile Number: (876) 967-4972 E-mail address: cxcwzo@cxc.org Website: www.cxc.org Copyright © 2007, by Caribbean Examinations Council The Garrison, St Michael BB14038, Barbados CXC A10/U2/07 ii Contents RATIONALE.....................................................................................................................................................1 AIMS ..................................................................................................................................................................1 SKILLS AND ABILITIES TO BE ASSESSED ...............................................................................................2 PRE-REQUISITES OF THE SYLLABUS .......................................................................................................5 STRUCTURE...
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