Bacteria Biology Mini Test PDF

Taxonomy Classifying 8 characteristics of living things - 1. Made of cells 2. Reproduce 3. Need and use energy 4. Grow and develop 5. Respond to stimuli, how they interact with environments and react to change 6. Movement 7. Exchange Gases, take and release 8. Excrete...

Taxonomy Classifying 8 characteristics of living things - 1. Made of cells 2. Reproduce 3. Need and use energy 4. Grow and develop 5. Respond to stimuli, how they interact with environments and react to change 6. Movement 7. Exchange Gases, take and release 8. Excrete waste Why is it important to classify? 1. Identify species 2. Farming practices 3. Medical disease identification, treatment using medicinal plants 4. Invasive species control 5. Conservation biology 6. Global communication of species Morphological Species Concept Focus on the morphology of an organism Morphology refers to: body size, shape and other structural features Organisms are compared and scientists decide whether similar organisms represent different species Advantages: Simple Disadvantages: Most populations are made up of non-identical individuals Biological Species Concept Defines a species taxon as a group of organisms that can successfully interbreed and produce fertile offspring. Organisms may appear to be alike and be different species Advantages: If two individuals can mate together in nature and produce viable offspring that can successfully live to also reproduce - easy: same species Disadvantage: BSC is not applicable to all species. After all, species that reproduce asexually cannot fit the BSC, which is based on sexual reproduction. Also, BSC cannot be applied to extinct species since the breeding experiments cannot be done. The species may also not be able to get to each other, but still could interbreed even if they do not. Phylogenetic Species Concept Focus on evolutionary relationships among organisms A species is defined as a cluster of organisms that is distinct from other clusters and shows a pattern of relationship among organism Advantage: Can be applied to extinct species and includes modern DNA analysis Disadvantage: Evolutionary history is not known for all species Naming Species Once it has been determined that something is a separate species, a name must be assigned Animals can have many différent names depending where you are in the world. Having a standardized system for naming across the world is essential Binomial Nomenclature Taxonomy - a branch of biology that identifies, names and classifies species based on natural features Binomial Nomenclature - a two-part naming system It assigns a two-word latin name to each species, often called a species or a scientific name First: Genus, Second: Species First word is written with a capital letter, with the whole name italicized when typed and underlined if handwritten Classifying Species Species concepts help determine which groups of organisms make up a species, and binomial nomenclature provides a formal name for each of those species Classification - The grouping of organisms based on a set of criteria that helps to organize and indicate evolutionary relationships Hierarchical Classification - Species are arranged in categories from most general to most specific - A system is nested when the elements that have a few items in them, have à subset of items of elements with more items - Ex. Sports, have team sports, team sports has hockey, soccer, etc Taxonomic Categories Groupings arranged in a hierarchy used to classify organisms that have been named and identified À species is assigned membership in eight nested categories Rank: A level in a classification system Taxon: The name of each rank - Ex. Grey wolf 1. Domain: Eukarya, Bacteria, Archaea - broadest of all the ranks (categories)  - All large organisms are also in this domain (humans, plants, animals) 2. Kingdom: Animal - fewer species within it than a domain (next level) 3. Phylum 4. Class 5. Order 6. Family 7. Genus 8. Species * Scientific name just uses genus and species Acronym: Doctor King Phillip Came Over For Good Spaghetti History of Taxonomy Aristotle - Classified living things into 2 large groups, plants and animals Kingdom Plantae - organisms that did not move and obtain food through photosynthesis Kingdom animalia - Organisms that could move and obtain food Problem: Lots of things don't fit into these categories - in the 1600s, views began to change due to the invention of the microscope. The microscope changed everything due to the ability to see “invisible” life, microorganisms Ernst Haeckel (1866): A german biologist proposed classifying all microorganisms into a third category, Kingdom Protista Mushroom and mould originally placed in Kingdom Animalia - but re-classified into a 4th kingdom called kingdom fungi. Scientists further classified the last two kingdoms using DNA technology - Kingdom Bacteria and Kingdom Archaebacteria - Archaebacteria are able to live in extreme environments and have different RNA and protein structures than those in kingdom Bacteria Carl Linnaeus was the father of taxonomy who founded binomial nomenclature Bacteria Prokaryote Pro - before Karyon - nucleus (no nucleus) The simplest forms of life are prokaryotes Earth's first cells were prokaryotes Prokaryotes are earth's most abundant life forms They can survive in many environments They can get energy from many différent sources Differences between prokaryotes and eukaryotes Eukaryotic cells contain membrane-bound organelles (such as the nucleus and mitochondria), while prokaryotic cells do not.  DNA in eukaryotic cells is found inside the nucleus, while DNA in prokaryotic cells is located in the cytoplasm. Eukaryotic cells are generally larger and more complex than prokaryotic cells. Characteristics of Bacteria Mostly single-celled No nucleus or membrane bound organelles Circular chromosomes Cell walls Reproduce asexually and sexually Prokaryotic Anaerobic or aerobic Heterotrophic or Autotrophic Structure of bacteria Very small A eukaryotic cell (us) is 10 x larger Bacteria Contain: 1. Cell wall: support and protect the cell 2. Cell membrane: Controls what enters/exits 3. Ribosomes: formation of proteins 4. DNA: single strand in a ring shape 5. Some contain a flagella: movement 6. Cell Shape 3 general shapes - 1. Spherical are called COCCUS 2. Rod are called BACILLUS - Causes E. Coli 3. Spiral are called SPIRILLUM Coccus Cocci that live as separate cells → Monococci In pairs → Diplococci Linear Chains → Streptococci  - Causes strep throat - Causes a severe infection of the skin, flesh eating disease Grapelike Clusters → Staphylococci Bacteria Diseases Coccus - Streptococci - Streptococcus causes strep throat - Causes a severe streptococcal infection of the skin, flesh eating disease (erysipelas) Coccus - Staphylococcus - Causes a staph infection BACILLUS - Causes E. Coli Spirochete - The spirochete Borrelia burgdorferi is a tick-borne parasite responsible for Lyme disease in humans - Blacklegged ticks are often carriers of Borrelia Burgdorferi - An infected tick may transmit lyme disease during the act of attaching and biting their host - Leptospira is type of spirochete bacteria that causes leptospirosis Gram Stain Bacteria can be classified by their reaction to a dye made of crystal violet and iodine called gram stain Gram Stain Colour Common Why Gram - Positive violet Very Different cell wall Not as pathogenic structure (thicker peptidoglycan cell wall)  Gram - Negative Light pink Not as common Much thinner More pathogenic peptidoglycan cell (bacteria that can wall cause diseases) Bacteria - Cell Wall Structure Bacteria are divided into two groups based upon the composition of their cell walls Gram positive: two layers (lipid, peptidoglycan - sugar/amino acids network) Gram Negative three layers, lipid, peptidoglycan and lipopolysaccharide. Obtaining Nutrients Autotrophs: Can make their own organic compounds (glucose) from CO2 With or without the sun Heterotrophs: Obtain energy by breaking down organic molecules from their environment Respiration This does not mean breathing. It is the process of breaking down compounds (glucose) to make energy (ATP) We know that prokaryotes do not have organelles like mitochondria and chloroplasts and other essential organelles needed for respiration so how do they make ENERGY? Aerobic respiration Oxygen is required These bacteria are called Aerobes If oxygen is absolutely necessary they are called obligate aerobes Anaerobic respiration Oxygen is not needed to make energy These bacteria are called anaerobes If oxygen will kill these bacteria they are called obligate anaerobes a third group of bacteria can survive with or without oxygen and are called facultative anaerobes - Ex. Cyanobacteria - Photosynthesis bacterium - Bluish-greenish color - Contain membranes that carry out the process of photosynthesis - Do not contain the same type of chloroplasts as plants do - This bluish-greenish algae can be found nearly everywhere on earth - Can survive in extremely hot environments and even extremely cold environments - They are not in the plant kingdom because they can exists unicellularly - Prokaryotic (no nucleus and membrane-bound organelles) Reproduction - Binary Fission  Bacteria reproduce asexually by binary fission (duplicate of chromosome, continued growth of the cell, division into two cells) Single chromosomes replicates and then cell divides Rapid All new cells identical (clones) Bacteria usually reproduce asexually using the process of binary fission The genetic material is duplicated and divided The cell membrane pinches and eventually divides into two cells (happens to E. Coli) Sexual Reproduction - Conjugation Bacteria reproduce sexually by conjugation Form a tube between 2 bacteria to exchange genetic material Held together by pili New cells not identical Bacterias version of sex Some bacteria reproduce sexually by exchanging some of their DNA through a “sex pilus” or conjugation tube to another bacterium Usually plasmid (circular) DNA, not genomic DNA Viruses Dependent on the internal workings of other cells - not capable of living independently Must invade host cells and use their machinery for survival and reproduction They are less than 0.1 um in diameter Hundreds of thousands can fit inside a typical human cell Classifying Viruses Have genetic material and reproduce - but are not cellular so not classified as regular organisms Often named according to the size and shape of the capsid Capsid: The outer protein layer that surrounds the genetic material of the virus Some shapes are small crystals, spherical, cylindrical, or a head attached to protein tail fibres Can also be classified according to the disease they cause - those that affect humans classified into 21 groups. Viruses with RNA Higher mutation rates Human immunodeficiency virus  Influenza viruses (covid) Rabies Measles, mumps, pneumonia, polio, common cold SARS Viruses with DNA Usually stable / constant, vaccines effective) Chickenpox, cold sores, genital herpes, Mononucleosis Hepatitis Respiratory infections, tumors Virus Reproduction Not cellular, no cell division Replication: genetic material is copied before reproduction - completed within a viruses host cell - Virus enters host cell to produce multiple copies of themselves - Copies are assembled by the host cell - One of replication two cycles is used - lytic or lysogenic Lytic Cycle The virus enters the cell, replicates itself hundreds of times, and then bursts out of the cell destroying it 1. Attachment 2. Injection/entry 3. Replication 4. Assembly 5. Realase (lysis = breaking open) Lysogenic Cycle  The virus enters the cell, viral DNA integrates with the host DNA and becomes inactive (this unit is called à provirus). The host functions normally. An environmental change may then cause the virus to enter the lytic cycle. 1. Attachment 2. Injection(injects its genetic material into the host cell)/entry 3. Integration into host cells DNA (Viral DNA becomes part of the host cell's chromosome (provirus stage)) 4. dormancy/normal cell functions 5. Triggering of viral DNA to be released and then lytic cycle begins Differences between Lytic and Lysogenic Cycles In the lytic cycle: - Viral DNA destroys Cell DNA, takes over cell functions and destroys the cell - The virus replicates and produces progeny phages (A progeny phage is a new virus particle that is produced when a virus infects a host cell. The virus replicates inside the cell, and as a result, many new copies are made. These new phages can then go on to infect other cells) - There are immediate symptoms of viral infection In the lysogenic cycle: - Viral DNA merges with cell DNA (becomes a provirus) and does not destroy the cell - The virus does not produce progeny right away - There are delayed symptoms of viral infection Retroviruses These viruses use reverse transcriptase to convert RNA into DNA and incorporate it into à host cell  When the host cell divides by mitosis, it replicates this virus along with its own DNA, which allows the virus to be replicated over and over again while undetected - it is à provirus At any time, the virus can separate from host chromosomes and enter the more damaging lytic cycle HIV is the most well known of these types of viruses Herpes Herpes - causes cold sores which may appear and disappear on people throughout their lifetime Appear - when viral cycle destroys cells Disappear - virus is in provirus stage Triggers may cause à switch from one phase to another Prions Prions are infectious particles made of abnormally shaped protein Non-genetic disease They become harmful when they change shape They lack DNA or RNA They are found in the brain and spinal cord of infected animals. They are transmitted to other animals when infected tissue is eaten. - Ex. Mad cow disease, creutzfeldt-jacob disease (caused by mutation), variant creutzfeldt-jacob disease (caused by eating contaminated meat) How are Pathogens Transmitted? Pathogen - an organism causing a disease to its host Contact - touching, shaking hands Exchange of bodily fluids - kissing, coughing, sneezing, blood, sexual contact Air - germ particles in the air that are breathed in Poor hygiene - lack of hand washing, poor food preparation, poor sanitary conditions, inadequate care of the sick Vectors - Organisms that carry the disease but don't express it themselves Helped by conditions that promote rapid bacterial growth - warm temp, high humidity, no disinfection Application of viruses Viruses have been used to study the basic mechanisms of molecular biology such as DNA replication, protein synthesis Viruses have also been used by geneticists to genetically modify organisms Virotherapy uses viruses to treat bacterial diseases and some form of cancer Viruses are also being used as biological insecticides. Protista Origin of Eukaryotes Eukaryotic cells more complex than prokaryotic cells: - Membrane bound nucleus and organelles - Many chromosomes that occur in pairs - Protists, fungi, plants and animals are composed of eukaryotic cells First eukaryotic organism is thought to have evolved about 1.5 billion years ago. Prokaryotes are as old as 4 billion years Protozoans (protists) possibly evolved from the 1st eukaryotes by Endosymbiosis This endosymbiotic theory was first stated by Lynn Margulis in 1967 Endosymbiosis Endosymbiosis - theory that explains how eukaryotic cells evolved from the symbiotic relationship (a relationship or interaction between two different organisms that share similar habitat) between two or more prokaryotic cells It explains the similarity of chloroplasts and mitochondria to free-living prokaryotes by suggesting that the organelles arose from prokaryotes through (endo)symbiosis. (they evolved from prokaryotic cells) One prokaryotic cell engulfs another prokaryotic cell but does not digest it Cells live together in a mutually benefiting relationship (symbiosis) becoming dependent upon each other Overview: The endosymbiosis theory suggests that eukaryotic cells (like plant and animal cells) evolved when one prokaryotic cell engulfed another, but didn’t digest it. Instead, the two cells formed a mutual relationship, benefiting each other. Over time, the engulfed cell became an important part of the host cell, evolving into organelles like mitochondria and chloroplasts. Evidence for this includes the fact that these organelles have two membranes, with the inner one similar to prokaryotes, their ribosomes resemble those of prokaryotes, they reproduce like bacteria through binary fission, and they have their own circular DNA, similar to that of ancient prokaryotes. Scientific Evidence for Theory of Endosymbiosis Present day mitochondria and chloroplasts each have two membranes. Their inner membranes are similar to those of ancestral prokaryotes, while their outer membranes match the cell membrane of the eukaryote.  The ribosomes found in these organelles are more similar to prokaryotic ribosomes than to ribosomes in eukaryotes These organelles reproduce by binary fission within the cell Each organelle contains a circular chromosome and gene sequences that match those of living prokaryotes Characteristics of Protista Domain Eukarya (eukaryotic cells) Mainly unicellular organisms “Misfits’ 3 groups of protists - 1. Animal-like protists: Amoebas, ciliates, flagellates, sporozoans 2. Fungus - like protists: Slime moulds, water moulds 3. Plant-like protists: euglenoids, diatoms, dinoflagellates, algae (green, red, brown) Animal Like Protists (protozoans) Heterotrophs - an organism that eats other plants or animals for energy and nutrients, consume other prokaryotes, organic wastes, other protozoans Some species are parasites, some are free living (not dependant on another organism for survival) Include 4 phylums (A phylum groups together related organisms on the basis of their fundamental characteristics): 1. Phylum Cercozoa 2. Phylum Ciliophora 3. Phylum Zoomastigina 4. Phylum Sporozoa Phylum Characteristics Ex. Phylum Cell membrane surface, no cell wall = changer shape Ex. Cercozoa Pseudopods (cytoplasm extensions for feeding and Amoeba (cercozoans) movement) Habitat: Salt water, fresh water, mud, intestines Amoeba Single celled No body shape Contain pseudopods (to move and eat) Eat by endocytosis (cells take in substances from their external environment by engulfing them with their cell membrane.) Trypanosoma Trypanosomes are flagellates protozoa that cause tropical diseases in humans and animals, including sleeping sickness  Trypanosomes are found in the bloodstream of various mammalian hosts where they proliferate (increase) as extracellular parasites (not in the cells of the host, but in the body). Phylum Characteristics Ex. Phylum ciliophora Short hair-like projections on cell surface paramecium (Ciliates) (cilia) used for movement and food sweeping Large and complex Free living or parasitic Paramecium Ciliates Many protozoans are covered with hairlike projections, or cilia, and are called ciliates The cilia move back and forth like oars to move the organism through water Unlike amoebas, ciliates have rigid outer covering called a pellicle that maintains their shape. The beating of cilia also sweeps food into its oral groove Food reaches the oral groove, the membrane pinches off, surrounds the food and a food vacuole is formed. The food vacuole finds a lysosome within the cell, breaking down the food with digestive enzymes Undigested food is discharged through the anal pore Paramecium have 2 nuclei- a large macronucleus and à smaller micronucleus Reproduction occurs by binary fission Paramecium reproduce sexually through conjugation - they line up along their oral grooves Phylum Characteristics Ex. Phylum Contain a flagella for movement (tail) Trichonympha  zoomastigina Hard protective outer coating (flagellates) Free living, parasitic or mutualistic Phylum Sporozoa Parasitic protists Plasmodium (sporozoans) Capable of asexual and sexual reproduction Malaria 228 million cases in 2018 Caused by protozoans in the plasmodium genus Fungus-like Protists Heterotrophic - living organisms, dead organisms and wastes Produces spores (à certain cell that is used for reproduction) Divided into 3 main groups: 1. Plasmodial (acellular) slime moulds 2. Cellular slime moulds 3. Water moulds Acellular Slime Mould (plasmodial) Not microscopic, slug like appearance Engulf food particles Feed on bottom of forests and dead material Single celled protists that have many nuclei During most of its life, an acellular slime mould is a plasmodium, a wall-less mass of cytoplasm with many nuclei that have divided over and over by mitosis This huge mass of cytoplasm streaks very slowly over an object using an extended network of strands called pseudopodia When food runs out, slime molds form fruiting bodies (structures that produce and release spores.) that produce spores (tiny reproductive cells that can grow into a new organism.). These spores scatter and grow into flagellated cells, which then fuse to form amoeboid cells (cells that can move and change shape). These amoeboid cells are diploid,  meaning they have two sets of chromosomes, and can eventually grow into new slime molds. (spores are produced through meiosis) Cellular Slime Moulds Feed by ingesting tiny bacteria or yeast cells Release chemical to gather food using pseudoplasmodium No relation to other slime mould Cellular slime moulds live in freshwater, in damp soil, or in decaying matter such as rotting logs In the feeding stage of their life cycle, they move about as amoebalike cells When food is scarce, they come together to form a large multicellular mass Eventually a fruiting body forms and releases spores Water Moulds Live on dead organic matter Can be parasitic to fish, insects and plants the organism (like a fungus or slime mold) grows thin, thread-like structures into the tissues of another organism (the host) to take nutrients or establish itself there. It’s a way for the organism to invade and live off the host Water moulds live in water, though there are a few species in this group that live on land. If you've seen cottony mould growing on a dead fish it was probably a water mould. Most water moulds are aquatic and feed on the remains of dead plants and animals. Most land species are helpful decomposers of dead matter, a few are serious plant parasites that attack crops like grapes and potatoes Phytophthora infestans, for example was the cause of the irish potato famine in the mid Plant-like Protists (Algae) Make their own food by photosynthesis Some can consume other organisms when light is unavailable 6 Phylums: 1. Dinoflagellates, unicellular 2. Red algae, multicellular 3. Brown algae, multicellular 4. Diatoms, unicellular 5. Green Algae, multicellular  6. Euglenoids, unicellular Diatoms Most diverse and abundant group of phytoplankton Rigid cell walls with silica on surface Reproduce asexually by mitosis Sexual reproduction when conscious are unfavorable Dinoflagellates Phytoplankton - unicellular, free floating, aquatic microorganisms Have two flagella that spin the organism Reproduce quickly = blooms Can live inside other organisms The red Tide À red tide is an event that occurs on the coastline when algae - a plant-like organism - grows out of control Caused by Gonyaulax, a dinoflagellate protist that spreads on the surface of the water The name “red tide” comes from the fact that overgrown algae can cause the water to change color. Red tides can be hazardous to human health and sea life. Euglenoids Phytoplankton Shallow freshwater Can be autotrophs or heterotrophs if dark Have light detecting structure = eyespot Euglena propels itself through the water by means of its flagellum Euglena obtains its nourishment in more than one way. In sunlight it is fully autotrophic using its chloroplasts to produce sugars through photosynthesis In the dark, the organism begins to lose its chlorophyll and feeds as à heterotroph on dead organic material in the water Green algae  Most are aquatic mainly freshwater some salt water Diverse habitats Most plant like of the 3 types of algae Can cause harmful algal blooms What happens when there's too much algae in the water? When algae overgrow in water, they can block sunlight, preventing underwater plants from photosynthesizing and disrupting the entire ecosystem. Excessive algae consumption of nutrients can lead to oxygen depletion, creating "dead zones" where aquatic life cannot survive. In some cases, harmful algal blooms (HABs) produce toxins that contaminate water and pose health risks to humans and animals. Why should we be concerned about algae in our water sources? Algae in water sources can lead to harmful algal blooms (HABs), which produce toxins that are harmful to aquatic life, animals, and even humans. These toxins can contaminate drinking water and make it unsafe for consumption or recreational use. Algal blooms also deplete oxygen levels in the water, disrupting ecosystems and causing fish kills. Key Differences Bacteria are unicellular, prokaryotic, and lack a nucleus. Plants are multicellular, eukaryotic, and mostly autotrophic (via photosynthesis), and have a cell wall Animals are multicellular, eukaryotic, and heterotrophic, usually engaging in sexual reproduction. Protists are eukaryotic and can be unicellular or multicellular, with diverse modes of nutrition (both autotrophic and heterotrophic).