Unit 10: Biodiversity

1. Unit 10: Biodiversity

2. Page 1: Viruses

3. Is a virus a living thing? • There has been debate about this, but most scientists think the answer is no • Viruses are not true cells, they are simply made of a protein coat called a capsid surrounding genetic material (DNA or RNA)

4. Different Virus Structures • T4 Bacteriophage (During infection, leaves its capsid outside the bacterial cell “victim” and injects its genetic material) • HIV Virus

5. Different Virus Structures • Influenza Virus http://www.youtube.com/watch?v=Rpj0emEGShQ&feature=related What are the locks, keys, copy machines, and chefs?

6. Is a virus a living thing? • In order to be living thing, viruses must be made of cells… but they are just protein coats around DNA • In order to be a living thing, viruses must be able to reproduce by themselves, but they can only replicate themselves when they are inside a host cell!

7. How does a virus replicate itself? • A virus makes a copy of itself using a process called the lytic cycle Step 1: Virus attaches to host cell’s membrane and injects its genetic material Step 2: Viral genetic material is transcribed and translated to make viral proteins inside host cell

8. How does a virus replicate itself? • A virus makes a copy of itself using a process called the lytic cycle Step 3: Viral proteins and new DNA or RNA are assembled into new viruses inside the cell Step 4: Host cell lyses (bursts) and releases new viruses

9. Lytic Cycle Infect, Copy, See Ya Later!

10. What are some example viruses in humans? • Ex: Rhinovirus (cold), influenza (flu), varicella (chicken pox), EBOV (Ebola) • Viruses are not bacteria so they can’t be cured using antibiotics…good luck immune system! • Viruses can infect specific host cells based on the types of proteins found in their capsids Child with chicken pox Ebola quarantine area

11. E Bola Virus • Also called hemorrhagic fever • Several strains of virus…most lethal strain is the Zaire strain (90% fatality rate) • Bleeding from mucous membranes (nose, intestines, gums, etc.) Ebola virus up close! Ebola outbreaks from 1979-2008…red dots are Zaire Strain!

12. Case Study of a Virus: HIV • HIV (Human Immunodeficiency Virus) is the virus that causes AIDS and attacks the T Cells of the immune system • HIV is called a retrovirus because it has RNA, not DNA, as its genetic material • It uses an enzyme called reverse transcriptase to copy RNA back into DNA

13. Case Study of a Virus: HIV • The new copied DNA becomes a part of the T Cell’s DNA (genome) and makes the T Cell unable to do its job (fight infection) • Because the host cell does not die, this process is called the lysogenic cycle, not the lytic cycle

14. Lytic vs. Lysogenic Cycles Lytic Cycle: Active Virus Lysogenic Cycle: Dormant Virus

15. Case Study of a Virus: HIV • HIV is spread through passing of body fluids (by sharing needles or sexual contact) • Certain body fluids carry more viruses than others…you’d have to drink a gallon of someone’s saliva to be infected by HIV!

16. Fun Facts About Viruses • The name virus comes from the Latin word for slimy liquid or poison • Over 1016 HIV genomes are produced daily on the entire planet. Many new viral mutants  medications can’t keep up! • In 1918 more people died from the influenza virus (approximately 30 million) than died in the First World War (10 million).

17. Diseases Caused by Viruses • Warts • West Nile • Polio • Hepatitis • Measles

18. What to know about viruses? • Basic virus structure (nucleic acid in protein coat) • Process of viral infection (lytic vs. lysogenic cycle)

19. Page 2: Bacteria

20. How are bacteria classified according to modern taxonomy? • Old system: all bacteria were placed in Kingdom Monera • New System: 2 bacterial kingdoms… Archaebacteria and Eubacteria

21. How are bacteria classified according to modern taxonomy? • Archaebacteria live in harsh environments (ex: deep sea vents and hot springs) • They can make their own food by taking in harsh chemicals from the environment and converting them to energy-rich molecules Deep sea vent with tubeworms Grand prismatic spring in Yellowstone

22. How are bacteria classified according to modern taxonomy? • Eubacteria are the “true bacteria.” They are mostly heterotrophs, but a few (ex: photosynthetic cyanobacteria) are autotrophic. • Heterotrophic bacteria can use aerobic respiration (needs oxygen) or anaerobic respiration (does not need oxygen) E. coli

23. Basic Characteristics

24. Label the Parts of the Bacterium • Yes, I know this is not exactly the same picture as you have in your booklet…YOU CAN DO THIS…I BELIEVE IN YOU! Pili (singular: pillus) are not the same as flagella! Flagella are longer and used for movement. Pili are shorter and are used for sensing things in the bacteria cell’s environment!

25. What are some potential uses for bacteria? • Genetic Engineering: the gene for human insulin can be inserted into the bacterial plasmid (a circular chromosome). The bacteria will the produce human insulin… which disease does this help treat? • Bacteria serve as saprophytes (decomposers) by breaking down living and dead organic matter

26. Cloning Human Insulin Gene Bacterial DNA with human insulin gene (green) stuck inside!)

27. Fun Facts about Bacteria • Almost one million bacteria can be “created” by one person in a school day • Bacteria 40 million years old have been extracted and successfully grown from a fossilized bee • One species of bacteria called Ralstonia metallidurans can produce solid nuggets from dissolved gold (eat it and then poop it out!

28. Diseases Caused by Bacteria • Lyme disease • Tuberculosis • Strep throat • Tooth decay • Tetanus

29. What to know about bacteria? • Characteristics of the archaebacteria and eubacteria • Bacterial cell parts and their functions • Possible roles of bacteria in the environment

30. Page 3: Protists

31. How are protists classified according to modern taxonomy? • Protists are found in Kingdom Protista • “Grab Bag Kingdom”: All unicellular eukaryotes that are not fungi, plants, or animals • Grouped based on how they compare to animals, plants, and fungi

32. Basic Characteristics

33. Animal-Like Protists • Heterotrophs (ingest other organisms) • Always unicellular • Classified by motility 1) Amoeba: False feet (pseudopods) extend from the cytoplasm 2) Paramecium: Cilia 3) Euglena: Flagella

34. Plant-Like Protists • Autotrophs • Either unicellular or multicelluar • Classified according to the pigments they use to capture sunlight • Sample organisms: brown algae (kelp), green algae, red algae, dinoflagellates, and diatoms

35. Plant-Like Protists • Colonial plant-like protists… Ex: Volvox • Colonial  many individual cells living together… connected by cytoplasm strings, all cells have eyespots to move together towards light • Inner groups of cells = daughter colonies created by asexual reproduction • Can also reproduce sexually

36. Plant-Like Protists • Algae can reproduce using alternation of generations: Have multicellular haploid and diploid forms…can reproduce using spores or gametes

37. Fungus-Like Protists • Heterotrophs (break down organic matter and absorb nutrients) • Includes the slime molds and water molds • Reproduce using spores

38. Fun Facts about Protists • A dinoflagellate causes the red tide • Malaria is spread by mosquitos carrying the protist plasmodium • African Sleeping Sickness is spread the tsetse fly carrying the protist trypanosomiasis

39. What to know about protists? • How are protists grouped? • How do protists obtain nutrients and move? • They are unicellular eukaryotes!

40. Page 4: Fungi

41. How are fungi classified according to modern taxonomy? • Found in Kingdom Fungi • Example Organisms: Mushrooms, molds, yeast • Grouped based on how they reproduce and where their spores are found

42. Basic Characteristics

43. Body Structure • Organize cells into hyphae, string-like structures for reproduction and food absorption

44. Basidiomycetes (Club Fungi) • Example Organisms: Common mushroom, puffball, shelf fungus • A structure called a fruiting body produces spores • Spores are attached externally on basidia

45. Ascomycetes (Cup Fungi) • Example Organisms: molds and yeasts • Sexually-Reproducing Cup Fungi: have male and female reproductive cells in sacs called asci. Produce spores internally. • Asexually-Reproducing Cup Fungi: Organisms like yeasts reproduce asexually by budding

46. Bread Molds • Example Organisms: Rhizopus stolonifer (black bread mold) • Sexual reproduction using structures called sporangia to produce spores • Have specialized hyphae called rhizoids to absorb food and water

47. Symbiotic Relationships • Lichen: Mutualism between fungus and algae…fungus helps algae retain water, algae provides food (photosynthesis) • Athletes Foot Fungus + Human: what type of relationship is this?

48. Fun Facts about Fungi • Leaf cutter ants have a mutualism with a fungus • Giant puffballs can be almost two feet long and contain seven trillion spores • Yeast infections or thrush can be caused by a fungus called Candida albicans

49. What to know about fungi? • How are the members of Kingdom Fungi grouped? • Use spores for reproduction • Basic Body Structure: Hyphae for food absorption (heterotrophs!)

50. Page 5: Plants