WEEKLY TOPIC: Homework
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Colonial Tunicates: Species Guide
SPECIES IN DEPTH Colonial Tunicates Colonial Tunicates Tunicates are small marine filter feeder animals that have an inhalant siphon, which takes in water, and an exhalant siphon that expels water once it has trapped food particles. Tunicates get their name from the tough, nonliving tunic formed from a cellulose-like material of carbohydrates and proteins that surrounds their bodies. Their other name, sea squirts, comes from the fact that many species will shoot LambertGretchen water out of their bodies when disturbed. Massively lobate colony of Didemnum sp. A growing on a rope in Sausalito, in San Francisco Bay. A colony of tunicates is comprised of many tiny sea squirts called zooids. These INVASIVE SEA SQUIRTS individuals are arranged in groups called systems, which form interconnected Star sea squirts (Botryllus schlosseri) are so named because colonies. Systems of these filter feeders the systems arrange themselves in a star. Zooids are shaped share a common area for expelling water like ovals or teardrops and then group together in small instead of having individual excurrent circles of about 20 individuals. This species occurs in a wide siphons. Individuals and systems are all variety of colors: orange, yellow, red, white, purple, grayish encased in a matrix that is often clear and green, or black. The larvae each have eight papillae, or fleshy full of blood vessels. All ascidian tunicates projections that help them attach to a substrate. have a tadpole-like larva that swims for Chain sea squirts (Botryloides violaceus) have elongated, less than a day before attaching itself to circular systems. Each system can have dozens of zooids. -
Volvox Barberi Flocks, Forming Near-Optimal, Two
bioRxiv preprint doi: https://doi.org/10.1101/279059; this version posted March 8, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Volvox barberi flocks, forming near-optimal, two-dimensional, polydisperse lattice packings Ravi Nicholas Balasubramanian1 1Harriton High School, 600 North Ithan Avenue, Bryn Mawr, PA 19010, USA Volvox barberi is a multicellular green alga forming spherical colonies of 10000-50000 differentiated somatic and germ cells. Here, I show that these colonies actively self-organize over minutes into “flocks" that can contain more than 100 colonies moving and rotating collectively for hours. The colonies in flocks form two-dimensional, irregular, \active crystals", with lattice angles and colony diameters both following log-normal distributions. Comparison with a dynamical simulation of soft spheres with diameters matched to the Volvox samples, and a weak long-range attractive force, show that the Volvox flocks achieve optimal random close-packing. A dye tracer in the Volvox medium revealed large hydrodynamic vortices generated by colony and flock rotations, providing a likely source of the forces leading to flocking and optimal packing. INTRODUCTION behavior (see, e.g., [8, 9] and references therein) but their interactions are often dominated by viscous forces (e.g. fluid drag) unlike larger organisms which are The remarkable multicellular green alga Volvox barberi dominated by inertial forces. Here, I show that V. [1] forms spherical colonies of 10,000 to 50,000 cells barberi colonies, which are themselves composed of many embedded in a glycol-protein based extra cellular matrix individual cells acting together, show collective behavior (ECM) and connected by cytoplasmic bridges that may at a higher level of organization. -
Introduction to the Cell Cell History Cell Structures and Functions
Introduction to the cell cell history cell structures and functions CK-12 Foundation December 16, 2009 CK-12 Foundation is a non-profit organization with a mission to reduce the cost of textbook materials for the K-12 market both in the U.S. and worldwide. Using an open-content, web-based collaborative model termed the “FlexBook,” CK-12 intends to pioneer the generation and distribution of high quality educational content that will serve both as core text as well as provide an adaptive environment for learning. Copyright ©2009 CK-12 Foundation This work is licensed under the Creative Commons Attribution-Share Alike 3.0 United States License. To view a copy of this license, visit http://creativecommons.org/licenses/by-sa/3.0/us/ or send a letter to Creative Commons, 171 Second Street, Suite 300, San Francisco, California, 94105, USA. Contents 1 Cell structure and function dec 16 5 1.1 Lesson 3.1: Introduction to Cells .................................. 5 3 www.ck12.org www.ck12.org 4 Chapter 1 Cell structure and function dec 16 1.1 Lesson 3.1: Introduction to Cells Lesson Objectives • Identify the scientists that first observed cells. • Outline the importance of microscopes in the discovery of cells. • Summarize what the cell theory proposes. • Identify the limitations on cell size. • Identify the four parts common to all cells. • Compare prokaryotic and eukaryotic cells. Introduction Knowing the make up of cells and how cells work is necessary to all of the biological sciences. Learning about the similarities and differences between cell types is particularly important to the fields of cell biology and molecular biology. -
Algae of the Genus Volvox (Chlorophyta) in Sub-Extreme Habitats T A.G
Short Communication T REPRO N DU The International Journal of Plant Reproductive Biology 12(2) July, 2020, pp.156-158 LA C P T I F V O E B Y T I DOI 10.14787/ijprb.2020 12.2. O E I L O C G O S I S T E S H Algae of the genus Volvox (Chlorophyta) in sub-extreme habitats T A.G. Desnitskiy Department of Embryology, Saint-Petersburg State University, Saint-Petersburg, 199034, Universitetskaya nab. 7/9, Russia e-mail: [email protected]; [email protected] Received: 18. 05. 2020; Revised: 08. 06. 2020; Accepted and Published online: 15. 06. 2020 ABSTRACT Literature data on the life of green colonial algae of the genus Volvox (Chlorophyta) in sub-extreme habitats (polar, sub-polar and mountain regions) are critically considered. Very few species (primarily homothallic Volvox aureus) are able to thrive in such conditions. Keywords : Geographical distribution, reproduction, sub-extreme habitats, Volvox. The genus Volvox Linnaeus (Volvocaceae, Chlorophyta) Peru (South America) at the elevation of more than five includes more than 20 species of freshwater flagellate algae thousand meters above sea level seems to be doubtful. The (Nozaki et al. 2015), providing an opportunity to study the illustration from this article (which focuses mainly on developmental mechanisms in a relatively simple system diatoms) shows a spherical colony with a diameter of about 14 consisting of two cellular types (somatic and reproductive). μm, consisting of several hundred very small cells (Fritz et al. Volvox carteri f. nagariensis Iyengar is a valuable model of 2015, p. -
Laboratory Exercises in Microbiology: Discovering the Unseen World Through Hands-On Investigation
City University of New York (CUNY) CUNY Academic Works Open Educational Resources Queensborough Community College 2016 Laboratory Exercises in Microbiology: Discovering the Unseen World Through Hands-On Investigation Joan Petersen CUNY Queensborough Community College Susan McLaughlin CUNY Queensborough Community College How does access to this work benefit ou?y Let us know! More information about this work at: https://academicworks.cuny.edu/qb_oers/16 Discover additional works at: https://academicworks.cuny.edu This work is made publicly available by the City University of New York (CUNY). Contact: [email protected] Laboratory Exercises in Microbiology: Discovering the Unseen World through Hands-On Investigation By Dr. Susan McLaughlin & Dr. Joan Petersen Queensborough Community College Laboratory Exercises in Microbiology: Discovering the Unseen World through Hands-On Investigation Table of Contents Preface………………………………………………………………………………………i Acknowledgments…………………………………………………………………………..ii Microbiology Lab Safety Instructions…………………………………………………...... iii Lab 1. Introduction to Microscopy and Diversity of Cell Types……………………......... 1 Lab 2. Introduction to Aseptic Techniques and Growth Media………………………...... 19 Lab 3. Preparation of Bacterial Smears and Introduction to Staining…………………...... 37 Lab 4. Acid fast and Endospore Staining……………………………………………......... 49 Lab 5. Metabolic Activities of Bacteria…………………………………………….…....... 59 Lab 6. Dichotomous Keys……………………………………………………………......... 77 Lab 7. The Effect of Physical Factors on Microbial Growth……………………………... 85 Lab 8. Chemical Control of Microbial Growth—Disinfectants and Antibiotics…………. 99 Lab 9. The Microbiology of Milk and Food………………………………………………. 111 Lab 10. The Eukaryotes………………………………………………………………........ 123 Lab 11. Clinical Microbiology I; Anaerobic pathogens; Vectors of Infectious Disease….. 141 Lab 12. Clinical Microbiology II—Immunology and the Biolog System………………… 153 Lab 13. Putting it all Together: Case Studies in Microbiology…………………………… 163 Appendix I. -
Biology Chapter 19 Kingdom Protista Domain Eukarya Description Kingdom Protista Is the Most Diverse of All the Kingdoms
Biology Chapter 19 Kingdom Protista Domain Eukarya Description Kingdom Protista is the most diverse of all the kingdoms. Protists are eukaryotes that are not animals, plants, or fungi. Some unicellular, some multicellular. Some autotrophs, some heterotrophs. Some with cell walls, some without. Didinium protist devouring a Paramecium protist that is longer than it is! Read about it on p. 573! Where Do They Live? • Because of their diversity, we find protists in almost every habitat where there is water or at least moisture! Common Examples • Ameba • Algae • Paramecia • Water molds • Slime molds • Kelp (Sea weed) Classified By: (DON’T WRITE THIS DOWN YET!!! • Mode of nutrition • Cell walls present or not • Unicellular or multicellular Protists can be placed in 3 groups: animal-like, plantlike, or funguslike. Didinium, is a specialist, only feeding on Paramecia. They roll into a ball and form cysts when there is are no Paramecia to eat. Paramecia, on the other hand are generalists in their feeding habits. Mode of Nutrition Depends on type of protist (see Groups) Main Groups How they Help man How they Hurt man Ecosystem Roles KEY CONCEPT Animal-like protists = PROTOZOA, are single- celled heterotrophs that can move. Oxytricha Reproduce How? • Animal like • Unicellular – by asexual reproduction – Paramecium – does conjugation to exchange genetic material Animal-like protists Classified by how they move. macronucleus contractile vacuole food vacuole oral groove micronucleus cilia • Protozoa with flagella are zooflagellates. – flagella help zooflagellates swim – more than 2000 zooflagellates • Some protists move with pseudopods = “false feet”. – change shape as they move –Ex. amoebas • Some protists move with pseudopods. -
And Development Could Be Examined in Detail. Prior to Darden's Work
CELLULAR DiFPERLENTIA TION IN VOLVOX* BY RICHARD C. STARR DEPARTMENT OF BOTANY, INDIANA UNIVERSITY, BLOOMINGTON Communicated by R. E. Cleland, January 29, 1968 MIicroorganiisms have become important research materials in the study of differentiation at all levels of organization from the molecular to the cellular, but there remains a wealth of species whose potential has not as yet been realized due to problems of isolation, cultivation, or manipulation of the various phases of the life cycle. In this latter group the green alga Volvox has for many years been recognized as having aspects of organization and development that would make it a prime species for investigation of differentiation at the cellular level. The Volvox individual is a spheroid in which the biflagellate cells are arranged in a single peripheral layer. Two types of cells are always present: somatic cells which characteristically make up the bulk of the organism; and reproductive cells which occur in small numbers and which may be differentiated as gonidia, i.e., asexual cells capable of reproducing new individuals without fertilization, or sexual cells capable of becoming eggs, or of forming packets of sperm cells. It is of special interest that many of the species of Volvox were delimited by such early workers as Powers' and Shaw2 using as taxonomic criteria the type and degree of differentiation, and the time at which such differentiation occurred during the development of the young individuals. The pioneering work by Darden3 on Volvox aureus showed the possibility of studying the control of the reproductive cells in cultured material where growth and development could be examined in detail. -
Introduction Why Did England Wish to Establish Colonies?
LIFE AT JAMESTOWN Introduction In May of 1607, three small ships – the Discovery, Godspeed and Susan Constant – landed at what we know today as Jamestown. On board were 104 men and boys, plus crew members, who had left England on a bitter cold December day. Sailing down the Thames River with little fanfare, they were unnoticed by all but a few curious onlookers. The ships were packed with supplies they thought would be most needed in this new land. Sponsors of the voyage hoped the venture would become an economic prize for England. An earlier undertaking in the 1580s on Roanoke Island, in what is now North Carolina, had failed, but times had changed. England had signed a peace treaty with Spain, and was now looking westward to establish colonies along the northeastern seaboard of North America. Word was that the Spanish had found “mountains of gold” in this new land, so these voyagers were intent on finding riches as well as a sea route to Asia. Little did the settlers know as they disembarked on this spring day, May 14, 1607, how many and what kinds of hardships they would face as they set out to fulfill their dreams of riches and adventure in Virginia. Life at Jamestown is a story of the struggles of the English colonists as they encountered the Pow- hatan Indians, whose ancestors had lived on this land for centuries, as well as their struggles among themselves as they tried to work and live with people of different backgrounds and social classes. It is the story of everyday life in an unfamiliar environment at Jamestown, including perilous times such as the “starving time” during 1609-10 and the expansion of the colony when more colonists, including women, came to strengthen the settlement and make it more permanent. -
ACTA PROTOZOOLOGICA Redaktor Naczelny: Zastępca Redaktora Naczelnego: Sekretarz Redakcji ZDZISŁAW RAABE STANISŁAW DRYL STANISŁAW L
PROTOZOOLOGICAACTA ''V.' i -XhM'i- i i ' ; m % & . / M ' J.JsSw. v.. w...... A .. ..sSSL. ..3 . - ,«.. REDACTORU M CONSILIUM S. DRYL (WARSZAWA), A. GRĘBECKI (WARSZAWA), O. JlROVEC (PRAHA), G. I. POLJANSKY (LENINGRAD), Z. RAABE (WARSZAWA), K. M. SUKHANOVA (LENINGRAD) VOLUMEN Vir Fasciculi: 1 — 10 WARSZAWA 19 6 9 http://rcin.org.pl INSTYTUT BIOLOGII DOŚWIADCZALNEJ IM. M. NENCKIEGO POLSKIEJ AKADEMII NAUK ACTA PROTOZOOLOGICA Redaktor Naczelny: Zastępca Redaktora Naczelnego: Sekretarz Redakcji ZDZISŁAW RAABE STANISŁAW DRYL STANISŁAW L. KAZUBSKI NOTICE TO AUTHORS Acta Protozoologica is intended as a journal serving for the publication of original papers embodying the results of experimental or theoretical research in ail fields of protozoology with the exception of purely clinical reports. The papers must be concise and will not be accepted if they have been previously published elswhere. After acceptance by the Editors papers will be printed in the order as they have been received, in the possibly shortest time. Papers are accepted in English, French, German and Russian. Every paper should begin with the name and postal address of the laboratory, name and the surname of the author, title in the language of the text, and translation of the title into the author's own language. The paper should be accompanied by a sum- mary in the language of the text, not exceeding 100 words, also the translation into the author's own language. The authors speaking English, French, German, or Russian should translate the title and the summary into another one of the 4 lan- guages accepted in the Journal. In the Russian texts also the name and the postal address of the laboratory, legends of tables, plates and text-illustrations must be translated, the translation of the summary may be somewhat more extensive, and the name of the author should be given additionally also in the Latin characters. -
Volvox Barberi Flocks, Forming Near-Optimal, Two-Dimensional
bioRxiv preprint doi: https://doi.org/10.1101/279059; this version posted April 1, 2018. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Volvox barberi flocks, forming near-optimal, two-dimensional, polydisperse lattice packings Ravi Nicholas Balasubramanian1 1Harriton High School, 600 North Ithan Avenue, Bryn Mawr, PA 19010, USA Volvox barberi is a multicellular green alga forming spherical colonies of 10000-50000 differentiated somatic and germ cells. Here, I show that these colonies actively self-organize over minutes into “flocks" that can contain more than 100 colonies moving and rotating collectively for hours. The colonies in flocks form two-dimensional, irregular, \active crystals", with lattice angles and colony diameters both following log-normal distributions. Comparison with a dynamical simulation of soft spheres with diameters matched to the Volvox samples, and a weak long-range attractive force, show that the Volvox flocks achieve optimal random close-packing. A dye tracer in the Volvox medium revealed large hydrodynamic vortices generated by colony and flock rotations, providing a likely source of the forces leading to flocking and optimal packing. INTRODUCTION of many individual cells acting together, show collective behavior at a higher level of organization. Entire colonies can dynamically gather into large populations that move The remarkable multicellular green alga Volvox barberi together, even while individual colonies can continue to [1] forms spherical colonies of 10,000 to 50,000 cells rotate separately. -
Protist Review.Pdf
Protists Termite mound Section 1 Introduction to Protists -!). )DEA Protists form a diverse group of organisms that are subdivided based on their method of obtaining nutrition. Termite colony Section 2 Protozoans— Animal-like Protists -!). )DEA Protozoans are animal-like, heterotrophic protists. Section 3 Algae—Plantlike Protists -!). )DEA Algae are plantlike, autotrophic protists that are the producers for aquatic ecosystems. Section 4 Termites Funguslike Protists SEM Magnification: 17؋ -!). )DEA Funguslike protists obtain their nutrition by absorbing nutrients from dead or decaying organisms. BioFacts • A protist that lives symbiotically Protists in termite gut in the gut of termites helps it LM Magnification: 65؋ digest cellulose found in wood. • The amoeba Amoeba proteus is so small that it can survive in the film of water surrounding particles of soil. • An estimated five million protists can live in one teaspoon of soil. 540 (t)Oliver Meckes/Nicole Ottawa/Photo Researchers, (c)Gerald and Buff Corsi/Visuals Unlimited, (b)Michael Abbey/Photo Researchers , (bkgd)Gerald and Buff Corsi/Visuals Unlimited Start-Up Activities Classify Protists Make this LAUNCH Lab Foldable to help you organize the characteristics of protists. What is a protist? The Kingdom Protista is similar to a drawer or closet in which you keep odds and ends that do not seem to fit any other place. The Kingdom Protista is composed of three groups of organisms that do not fit in any STEP 1 Fold a sheet of notebook paper other kingdom. In this lab, you will observe the three in half vertically. Fold the sheet into thirds. groups of protists. Procedure 1. -
Biology • Environment • Chemistry MEMORABLE TEACHING MADE EASY!
3bscientific.com Biology • Environment • ChemistryBiology • Environment NATURAL SCIENCES NATURAL 3B SCIENTIFIC® NATURAL SCIENCES 3bscientific.com 9000953 EN MEMORABLE TEACHING MADE EASY! Dear customer, Discover the variety of possibilities for making your teaching even more memorable and exciting. We have assembled a wide range of products and experiments for you for teaching various course content in biology. We can offer you detailed models, high-quality preparations and realis- tic replicas that illustrate the structures of plants, animals, humans and the earth as well as numerous experiment sets to aid independent study, practicing and learning. From page 104 onwards, you can browse through the selection of products relating to the earth sciences, ecology and chemistry. These include models of the structure of the earth, rock collections, measuring equipment for water and soil analysis, molecule construction kits and chemical measuring instruments. New and worthy of particular mention are the powerful and comprehensive Coach 7 measuring and analysis software, the VinciLab data logger and the €lab lab interface, as well as the numerous sensors for the measurement of biological and chemical para- meters (page 152 onwards). Representing a further innovation in our range are the devices for neurophysiological studies on intact earthworms. You can find these on page 94 onwards. Let yourself be inspired by our wide range. It’s well worth a look! Our competent team will be happy to advise you personally and is looking forward to receiving your suggestions and orders! We look forward to hearing from you! The 3B Scientific team ›NEW IN ZOOLOGY Limbs of various mammals The dissected real limbs enable scientific comparison of the anatomy of the front or rear legs of selected mammals and allow conclusions to be drawn about their walking and running behavior.