1. Microorganisms

2. Viruses
Biological particle composed of genetic material and protein Cause diseases Virulent –immediate Temperate - not immediately Obligate Parasite - only reproduces in a living host

3. Viruses
Comparison with cells Constructed of compounds usually associated with cells Have some characteristics of life but not all No nucleus, cytoplasm, organelles, or cell membrane Don't reproduce by either mitosis or meiosis. Not capable of carrying out cellular functions Contain nucleic acids Can crystallize where cells cannot.

4. Viruses Viral Structure Core of nucleic acid - either RNA or DNA
Core surrounded by protein layer called Capsid
Made of repeating protein units called Capsomeres  
Gives virus its shape.  
Function of viral nucleic acid  
Codes for production of viral nucleic acid.  
Control manufacture protein coat.  
Shape  
Icosahedron - 20 triangular faces; Most common shape
Polio, chicken pox, colds  
Helix - subunits of coat form spiral chain - like coiled spring
Rabies, mumps  
Strands surrounded by 2 protein layers - inner protein layer surrounded by lipid layer with embedded glycoproteins
HIV.  

5. Viruses

6. Viruses Classification Major division RNA Viruses DNA Viruses
Lower levels based on shape and size.  
Retroviruses - contains enzyme Reverse Transcriptase
Directs host cell to make DNA using viral RNA of virus as a template.  
Disease causing particles - smaller and simpler than virus  
Viroid - short, single strand of RNA with no capsid interferes with normal cell functions  
Prion - glycoprotein particle contains polypeptide of about 250 amino acids - no nucleic acid.  

7. Viruses Bacteriophage(Phage) - virus that infects bacteria
Have been used to gather information about viral replication.  
Have round, oval, or many sided heads and hollow tails  
Head contains nucleic acid.  
Tail has fibers at tip
Anchors phage to bacteria

8. Viruses

9. Viruses
Lytic Cycle - fundamental reproductive process of viruses Consists of 5 phases. Attachment Entry Replication Assembly Release

10. Viruses

11. Viruses Lysogenic Cycle Involves temperate viruses
Viruses enter cell similar to lytic cycle
Consists of a small segment of DNA
Prophage  
Viral DNA becomes additional set of genes
Incorporates into host's DNA
Replicates with host DNA  
External stimulus - radiation, chemicals - cause prophage to become virulent  

12. Viruses

13. Viruses Evolution Believed to have evolved after cells
May be simplification of some existing cells.

14. Kingdoms Eubacteria and Archaebacteria
Most common members - bacteria
Bacteria Characteristics  
Prokaryotic - no nucleus
Microscopic  
Heterotrophs or autotrophs  
Evolution  
Fossil monerans billion years old.  
Evolved into many forms - live in different environments.  
Classification difficult; rely on physiology  

15. Kingdoms Eubacteria and Archaebacteria
Classification - 2 Kingdoms
Kingdom Archaebacteria  
Kingdom Eubacteria  

16. Kingdom Archaebacteria
 Adapted to harsh environments  
Include methanogens, extreme halophiles, and thermoacidophiles.  
Methanogens
Anaerobic
Use carbon dioxide and hydrogen to form methane
Live in bog and lake bottoms, digestive tracts of livestock, and sewerage treatment plants.  
Halophiles - live in high salt areas  
Thermoacidophiles - live in very acidic and hot areas  

17. Kingdom Archaebacteria

18. Kingdom Eubacteria
All members of which we commonly call Bacteria Identification Classified on basis of shape Coccus - spherical shaped cells Bacillus - Rod shaped cells Spirillum - Shaped like coiled rods or corkscrews Cells can cluster together or form chains or filaments Staphylo - cluster Strepto -filament Diplo - pairs Classified on reaction to Gram stain - stains pink or purple Gram-Negative - pink - difficult to treat with antibiotics Gram-Positive - purple -treated with antibiotics

19. Kingdom Eubacteria

20. Kingdom Eubacteria Two specialized Phyla Phylum Cyanophyta
Blue-green bacteria (algae)
Similar to plants and plant-like protists
Photosynthetic - produce food and oxygen.
Clump to form colonies
Exhibit some division of labor
Phylum Prochlorophyta
Photosynthetic
Live symbiotically with tunicates
Chlorophyll similar to eukaryotes.

21. Biology of Bacteria Structure and Movement
DNA arranged in single circular chromosome  called plasmids
Cell walls differ from eukaryotes - some rigid, others flexible  
Many produce Capsule - protective polysaccharide layer.  
Glycocalyx - polysaccharide that helps many stick to surfaces
Pili - Protein strands to attach themselves to objects  
May form endospores under adverse conditions
Permits bacteria to lie dormant for years.  
Favorable conditions, endospore breaks; cell becomes active.  
Movement  
Many move by rotating stiff flagellum bent into S-curve.  
Spirochetes use filament that wraps around cell to move  

22. Biology of Bacteria

23. Biology of Bacteria
Nutrition May be heterotrophic or autotrophic Most are Heterotrophic Saprophyte feeds on dead or decaying matter. Parasite feeds on living materials Some Autotrophic Photoautotrophs - use sunlight as energy source. Chemoautotrophs - use energy of chemical reactions to synthesize food. Nitrogen Fixation - gaseous nitrogen converted into ammonia compounds

24. Biology of Bacteria Respiration
Obligate Anaerobes - cannot survive in presence of oxygen.  
Facultative Anaerobes - can live with or without oxygen.  
Obligate Aerobes - cannot live without oxygen.  

25. Biology of Bacteria Reproduction
Some reproduce rapidly - divide every minutes  
Binary Fission - cell reproduces by splitting in two  
Asexual  
DNA replicates first  
Plasma membrane and cell wall grows inward form 2 identical daughter cells.  
Conjugation - type of sexual reproduction, genetic material exchanged.  
Recombination of genetic material by 2 bacteria  
Portion of DNA from one cell passes across bridge formed by pili.   
Recipient DNA destroyed and new DNA is substituted

26. Biology of Bacteria Toxin Production
Pathogen - any organism that causes disease.  
Most bacterial diseases caused by toxins produced by bacteria.  
Toxin - poisonous substance that disrupts metabolism of infected organism.  
Endotoxin - pieces of cell wall of Gram-negative bacteria
Symptoms - fever, weakness, and damage to circulatory system
Example - Typhoid Fever.  
Exotoxin - products of bacterial metabolism
Secreted into area around bacteria
Most potent poisons known
Examples - Diphtheria and Botulism (food poisoning)  

27. Biology of Bacteria

28. Kingdom Protista Characteristics Eukaryotic - have true nucleus.
Eukaryotic - have true nucleus.  
Most are unicellular but some live in colonies.  
Does include some simple multicellular organisms - lack specialized tissues.  
Some autotrophic; others heterotrophic.  
Live in aquatic or moist environments.  
Reproduce sexually and asexually.  

29. Kingdom Protista
Organisms placed in this kingdom because they don't have characteristics of organisms in other kingdoms.  
Separated into 3 broad groups.  
Prototozoa - heterotrophic protists; "first animals"  
Algae - autotrophic protists.  
Unusual Protists - fungus like protists  

30. Protozoa General Characteristics Heterotrophic
Most are unicellular, some form colonies - most are microscopic.  
Live freely or as parasites (in the intestines is common)  
Many free living protozoans makeup zooplankton
Unicellular, heterotrophic organisms that drift in water.  
Parasitic forms cause disease  

31. Protozoa

32. Protozoa
Most lack a protective outer covering - semipermeable cell membrane serves as boundary.  
Most have physiological mechanism for monitoring and responding to environment.  
Sense touch and chemical changes - will bypass noxious chemicals.  
Eyespots (in some) - Localized region of pigment that detects changes in quality and quantity of light.  
Classified into 4 phyla - based on mode of movement.  
Phylum Sarcodina - move by pseudopodia  
Phylum Ciliophora - move by cilia  
Phylum Zoomastigina - move by flagella.  
Phylum Sporozoa - immobile; parasites  

33. Sarcodina - Amoeba
Most have flexible cell membrane; Some marine forms have calcium carbonate shells.
Move by means of pseudopodia - Ameboid Movement  
Pseudopodium - "False Foot" - cytoplasmic extension that functions in movement.  
Cytoplasm has 2 regions  
Ectoplasm  
Endoplasm 
Ameboid Movement - internal flow of cell contents.  
Excess water excreted by Contractile Vacuole
Ingest nutrients (food) by phagocytosis
Undigested food and water excreted by Exocytosis
Reproduce by Binary Fission - identical offspring.  
Form Cysts - protective outer wall - when conditions are bad  

34. Sarcodina - Amoeba

35. Ciliophora - Paramecium
Move by Cilia - short, hairlike projections
Paramecium has rigid protein covering called Pellicle - shaped like shoe sole.
Has 2 kinds of nuclei  
Macronucleus - large; control cell activities
Micronucleus - small; involved in sexual reproduction  
Foodgetting and Digestion  
Food enters through funnel-like Oral Groove -.  
Cilia sweeps food to Mouth Pore .  
Mouth pore opens into a Gullet, forms food vacuoles
Contents of vacuole digested and absorbed.  
Indigestible matter in vacuole moves to the Anal Pore -eliminated.  
Exhibit Avoidance Behavior - move away from harmful conditions
Reproduction  
Asexual - Binary Fission - macronucleus splits– one part to each
daughter cell.  
Sexual – Conjugation - involves 2 mating strains; (+) or (-)  

36. Ciliophora - Paramecium

37. Zoomastigina (Mastigophora)
Move by 1 or more long, whiplike Flagella  
Many freeliving.  
Some are parasitic
Best known - Trypanosoma - African Sleeping Sickness
Transmitted by tsetse fly - live in Africa  

38. Sporozoa All parasitic.
No means of locomotion - in body fluids of hosts.  
Reproduce by spores.  
Example - Plasmodium  
Causes Malaria  
Complex Life Cycle - in female Anophiles sp. - mosquito  
Spores enter blood stream thru mosquito saliva  
Spores reproduce asexually - infect red blood cells - rupture releasing toxin and more spores - causes chills and fever.
Mosquito bites infected person some of cells ingested - become gametes - combine and divide - migrate to mosquito's salivary glands to begin cycle again.  

39. Sporozoa

40. Algae General Characteristics Eukaryotic, plantlike protists
Autotrophic protists - produce food by photosynthesis.  
Most aquatic - terrestrial forms in moist situations.  
Unicellular and multicellular forms (large forms discussed with plants)  
Thallus - Body of an alga - unicellular, colonial, filamentous, or thalloid.  
Phytoplankton - photosynthetic plankton  
Provide food for numerous aquatic organisms  
Generates great amounts of oxygen.
Were classified in past as plants
Gametes formed in unicellular gametangia, plant multicellular gametangia.  
Classified into 4 phyla - based on color, food storage substances, and cell wall composition.  
All contain chlorophyll a; usually have other forms of chlorophyll  
Contain accessory pigments.  

41. Chlorophyta – “Green” Algae
Unicellular, colonial, filamentous, or thalloid  
Most aquatic or moist terrestrial environments  
Photosynthetic Pigments - Chlorophylls a and b; xanthophylls, carotenes  
Food stored as starch.  
Cell wall composition - Polysaccharide, sometimes cellulose  
Importance - Believed to be ancestors of plants  

42. Chlorophyta – “Green” Algae

43. Chrysophyta – “Golden Brown” Algae
Mostly unicellular  
Photosynthetic pigments - Chlorophylls a and c; Carotenes - fucoxanthin  
Food stored as Chrysolaminarin - oily carbohydrate  
Cell wall if present of cellulose, some contain silica  
Most members are Diatoms  
Marine and freshwater specimens  
Have silica containing shells - highly ornamented, double walls.  
Halves fit together like a box - half called Valve  
Types  
Centric Diatoms - circular or triangular valves - marine waters.  
Pennate Diatoms - rectangular valves - freshwater ponds and lakes  
Responsible for bulk of worldwide photosynthesis.  
Diatom shells don't decompose - forms Diatomaceous Earth - abrasive - ingredient in detergents, paint removers, fertilizers, insulators, scouring powders.  

44. Chrysophyta – “Golden Brown” Algae

45. Pyrrophyta – “Fire” Algae
Most are marine; oceanic phytoplankton - called Dinoflagellates - all unicellular  
Photosynthetic pigments - chlorophylls a and c; Carotene  
Food stored as starch  
Cell wall of cellulose - looks like armor.  
responsible for Bioluminescence - light produced by living things.  
Produce "Red Tides" - discoloration of ocean ; population explosion of dinoflagellates - produce toxins may cause respiratory paralysis in vertebrates  

46. Pyrrophyta – “Fire” Algae

47. Euglenophyta – “True Eye” Algae
Have characteristics of green algae and protozoa.
Contain chlorophylls a and b, carotenes in some.
Food stored as a starch - Paramylon
Have no cell wall, surrounded by pellicle
Not completely autotrophic, heterotrophic - in the dark.
Mostly freshwater species.
Contractile vacuole gets rid of excess water.
Moves by whipping flagellum.  
Red-orange eyespot functions as light detector

48. Euglenophyta – “True Eye” Algae

49. Fungus Like Protists
Members of group traditionally classified as fungi - actually are protists
Life cycles look fungus like  
Store food as glycogen
Morphological differences considered superficial  

50. Fungus Like Protists Phylum Acrasiomycota - Slime Molds
Live mostly on land or in freshwater.  
Feeding stage - Myxameba - uninucleate cell  
Live on forest floor or on decaying plants  
Move and feed like amoeba  
During environmental stress myxameba come together to form a Pseudoplasmodium  
Group of individual cells that act as one unit 
Moves together.  
Unit forms sporangia that produce spores  
Spores develop into individual myxameba  

51. Fungus Like Protists

52. Fungus Like Protists Phylum Myxomycota - Plasmodial Slime Molds
Feeding stage - Plasmosium - multinucleate cytoplasm surrounded by a membrane that moves as a mass, feeds on organic matter  
Stressful periods - plasmodium becomes stationary - produces sporangia on stalks  
Sporangia produce spores - may be dormant for years.  
Spore releases myxameba or flagellate swarm cells  
Cells fuse; nucleus for zygote divides repeatedly  
Doesn't undergo cytokinesis
Multinucleate plasmodium  

53. Fungus Like Protists

54. Kingdom Fungi Diverse group living in many different habitats.
Characteristics  
Eukaryotic  
Many microscopic; some easy to see.  
Important as decomposers - breakdown organic materials  
Release inorganic materials to environment to be reused.  
Most are either parasitic or saprophytic; a few predatory.  
Parasite - organism that lives off of living organisms.  
Saprophyte - organism that lives off of dead organisms or waste products.  
Generally grow in moist environments.  

55. Kingdom Fungi Characteristics
Composed of vegetative filament called a Hypha - may or may not be divided by cross walls.  
Coenocytic - filaments without crosswalls.  
Hypha may be have perforated crosswall - Septum.  
Hypha grows at tip.  
Mycelium - a mat of interwoven hyphae.  
Made of Chitin - complex polysaccharide, also in exoskeleton of arthropods and insects.  
Food stored as glycogen.  

56. Kingdom Fungi Characteristics Reproduce both sexually and asexually.
Asexual Reproduction  
Produce spores on special branches of hypha  
Spores often carried by wind.  
Finds suitable food source germinates; new hyphae grows 
May reproduce asexually by fragmentation  
Sexual Reproduction  
Gametes from 2 mating strains undergo cytoplasmic fusion.  
Nuclei don't fuse immediately - divide independently.  
Heterokaryotic - different nuclei
Homokaryotic - similar nuclei.

57. Kingdom Fungi Classification Basis Structure of hyphae
Coenocytic Hyphae – No crosswalls  
Septate Hyphae - With crosswalls  
Unicellular Hyphae - single cell  
Type of Reproduction - particularly spore type.  
Five Phyla  
Phylum Oomycota  
Phylum Zygomycota  
Phylum Basidiomycota  
Phylum Ascomycota  
Phylum Deuteromycota  

58. Oomycota
Aquatic and terrestrial species - water molds, white rusts, and downy mildews  
Both parasitic and saprophytic  
Coenocytic with branched hyphae  
Cell walls have cellulose not chitin  
Reproduction  
Male gametangium, antheridium, release sperm  
Female gametangium, oogonium, forms egg  
Fusion of egg and sperm develops thick-walled diploid Oospore  
Oospore germinates into coenocytic hyphae  
Asexual reproduction - flagellated zoospores produce hyphae  
Example - Phytophthora infestans   - Late Blight of Potatoes  
Irish Potato Famine of  
Result - mass migration of Irish to United States.  

59. Zygomycota – Rhizopus Bread Mold
terrestrial organisms  
Coenocytic - hyphae lack septa  
Reproductive structures are separated from other hyphae by unperforated cross walls  
Rhizopus consists of 3 types of hyphae  
Rhizoids - anchoring hyphae – absorb nutrients  
Stolons - hyphae that grow across surface of bread  
Sporangiophore - upright hyphae - sporangia at their tips  
Reproduction  
Asexual - spores from a sporangium on sporangiophore.  
Sexual - Conjugation - two strains unite to form a Zygospore  
Favorable conditions -asexual reproduction
Unfavorable conditions - sexual reproduction

60. Zygomycota – Rhizopus Bread Mold

61. Basidiomycota – Club Fungi
Mushrooms, toadstools, puffballs, rusts, and smuts - mostly terrestrial
Septate hyphae
Underground hyphae produce Basidiocarp - reproductive body
Mushroom is a basidiocarp.
Stalk - stem-like portion
Cap - flattened top portion
Gills - radiating rows under cap - site of basidia;
Basidium - club-shaped reproductive cell; produces Basidiospores
Hyphae grows - septa form - called Primary Mycelium
Hyphae grow,fuse with another mating strain – Secondary mycelium forms.  
Hyphae heterokaryotic - one nucleus in each cell.  
Secondary mycelium forms basidiocarp.  
Asexual reproduction by fragmentation.  
Importance  
Rusts - parasites of many cereal crops  
Smuts - plant pathogens - particularly corn  
Mushrooms - some food value  

62. Basidiomycota – Club Fungi

63. Ascomycota – Sac Fungi
Includes yeasts, molds, mildews, and morels - terrestrial and aquatic species.  
Have septate or unicellular hyphae  
Reproduction  
Asexual  
Spores called Conidium – on Conidiophores  
Yeast asexual reproduction is by Budding  
Sexual  
Two mating strains form male or female gametangia  
Female gametangium – Ascogonium  
Male gametangium – Antheridium  
Gametangia fuse - nuclei pair but don't fuse  
Hyphae intertwine form an Ascocarp - reproductive body  of ascomycete; contains sacs -Asci (ascus) that produce ascospores.  
Yeast important – able to breakdown carbohydrates  
Bread/Baking Industry - use carbon dioxide from anaerobic respiration  
Brewing Industry - fermentation of juices/liquids  

64. Ascomycota – Sac Fungi

65. Deuteromycota Imperfect Fungi
Taxonomic holding tank - fungi that where no sexual reproductive phase has been discovered.  
Have characteristics similar to ascomycetes  
Classified on basis of asexual reproduction.  
Aspergillis and Penicillium - former deuteromycetes now classified as ascomycetes  
Aspergillis - ferments soy beans makes soy sauce  
Penicillium - produce antibiotic penicillin; gives flavor to Roquefort and Camembert cheeses  
Septate hyphae  
Terrestrial species  
Asexually Reproduce by conidia.  

66. Deuteromycota Imperfect Fungi

67. Symbiotic Relationships
MUTUALISM - type of symbiosis in which both organisms benefit Examples Mycorrhizae Symbiotic association between fungi and plant roots Lichens Symbiotic association between a fungus (usually an ascomycete and a green algae or cyanobacteria

68. Mycorrhizae Symbiosis between fungi and plant roots
Help plants absorb water and nutrients
Fungus forms extensive network of hyphae in soil - increases surface area.  
Action of fungal enzymes provide nutrients that can be readily absorbed by the plant.  
Fungi absorbs of sugar produced by plant

69. Mycorrhizae

70. Lichens
Symbiosis between a fungus (usually an ascomycete and a green algae or cyanobacteria
Considered symbiotic-may be a controlled parasitism
Fungal hyphae penetrate algal cells and absorb food
Fungal member provides some protection against drying of algae.
Lichens classified according to thallus  
Crustose - grow surface of rocks and trees  
Foliose - have leafy thallus  
Shrubby - upright growth; also called 2-fold lichens  

71. Lichens

72. Disease
Any change, other than injury, that interferes in normal functioning of a body.  
Pathogen - Disease causing microorganism
Infection - Invasion of a body by a pathogen.

73. Germ Theory of Disease Idea that disease is caused by microorganisms.
Earlier belief was that disease was caused by evil spirits, magic, or miasmas (vapors of marshes or decaying organic matter.)  
Based on work of Louis Pasteur (French) and Robert Koch (German)  
Koch’s Postulates  
Microorganism should always be found in host but not in a healthy organism.  
Microorganism must be isolated and grown in pure culture away from host.  
When microorganisms of pure culture are injected into new host, they should cause disease.  
Microorganisms should be reisolated from second host and grown in pure culture and identified as the same as the original pure culture.  

74. Germ Theory of Disease

75. Disease
Agents of Disease  
Viruses  
Bacteria  
Fungi  
Protozoa