UNIT 3 – MICROBIOLOGY

1. UNIT 3 – MICROBIOLOGY

2. Where did we come from? DO NOT COPY… For Entertainment Purposes Only!

3. The Beginnings of Life • The earth is ~ 4.567 billion years old • Think of the earth’s history as one 24h period (each second = 53 000 yrs) • The universe began 2 days ago (14 billion y.a.) • First signs of life at 3 am: “replicator” (4 billion y.a.) • First prokaryotic cell at 5:20 am (common ancestor) (survived in CO2 and water) • 8 am – Organisms began to use light as an energy source – photosynthesis (oxygen was produced and was toxic!) • Oxygen and UV combine to create the ozone layer…the atmosphere was formed!

4. Early days on planet Earth

5. The Beginnings of Life • 2 pm – Bacteria and Archaea, and eukaryotes combine…endosymbiosis • Small organelles like mitochondria and chloroplasts fuse into larger cells. • 6:15 pm – plant, animal, fungi lines begin to form • 7:15 pm – Multicellular plants and water animals form • 10:12 pm - (340 million y.a) the evolution of the amniotic egg allowed eggs to be laid on land. The super-continent Pangea

6. The Beginnings of Life • 2 seconds before midnight– Homo sapiens arise

7. HOW MANY ORGANISMS? • 287,655 plants, including: • 15,000 mosses, • 13,025 ferns, • 980 gymnosperms, • 199,350 dicotyledons, • 59,300 monocotyledons; • 74,000-120,000 fungi; • 10,000 lichens;

8. HOW MANY ORGANISMS? • 1,250,000 animals, including: • 1,190,200 invertebrates: • 950,000 insects, • 70,000 molluscs, • 40,000 crustaceans, • 130,200 others; • 58,808 vertebrates: • 29,300 fish, • 5,743 amphibians, • 8,240 reptiles, • 9,934 birds, • 5,416 mammals.

9. BIODIVERSITY

10. The Amazon – An example of Biodiversity • 1 million insect species. • Tens of thousands of plants. • 2000 birds and mammals. • To date, at least 40,000 plant species, 3,000 fish, 1,294 birds, 427 mammals, 427 amphibians, and 378 reptiles have been classified. • Scientists have described between 96,660 and 128,843 invertebrate species in Brazil alone. • One square km may contain over 75,000 types of trees. • One square km can contain about 90,790 tons of living plants. • This constitutes the largest collection of living plants and animal species in the world. • One in five of all the birds in the world live in the rainforests of the Amazon.

11. The Amazon – Under Seige • 1/5 has been destroyed • Between 1991 and 2000 an area 2x the size of Portugal has disappeared. • 52 000 square Km are disappearing per year…mostly for cattle farms.

12. It is estimated that we are losing 140 000 species a year!

13. MORE NUMBERS… Organism NumberEstimated # to be Discovered • Viruses 5,000 500,000 • Bacteria 4,000 400,000-30 million • Fungi 70,000 1.5 million • Protozoans 40,000 100,000-200,000 • Algae 40,000 200,000-10 million • Flowering plants 250,000 300,000-500,000 • Roundworms 15,000 500,000-1 million • Mollusks 70,000 200,000 • Crustaceans 40,000 150,000 • Spiders and mites75,000 750,000-10 million • Insects 950,000 8-10 million • Vertebrates 45,000 50,000

14. CLASSIFYING LIVING THINGS • We have a lot of critters to organize! • The science of classifying organisms, called TAXONOMY, has 2 purposes: • Categorize (organize) all living things • Speak in a language that every scientist can understand (unifying system) • Present system developed by Karl von Linne (Latin = Carolus Linnaeus) • System based on an organism’s structure • The more features in common, the closer the relation.

15. HOW DO BIOLOGISTS KEEP TRACK OF ALL THESE ORGANISMS?

16. CLASSIFYING LIVING THINGSLinnean System of Classification • Binomial nomenclature… • The first part of any scientific name is called the genus. A genus may be used alone. First letter capitalized. (Written in italics.) • The second part is called the species and is never used alone. (Written in italics.) • Eg. Canis lupis, Escherichia coli (E. coli)

17. TAXA • Kingdom Less similar (broad category) • Phylum • Class • Order • Family • Genus • SpeciesVery similar (narrow category) • Each different level of hierarchy is called a taxon • “King Philip Could Order Four Good Salads”

18. Classification:

19. Kingdom Animalia • Cells do not have cell walls • All are multicellular • All are Heterotrophs • Most reproduce sexually • Live in terrestrial and aquatic habitats • Includes invertebrates (no backbone) and vertebrates (have backbone) • e.g. Clam, fish, turtle, cat, human

20. Kingdom Plantae • Cell walls contain cellulose • All are multi-cellular • Autotrophs • Most reproduce sexually and asexually • Have chloroplasts • e.g. Mosses, ferns, seed plants

21. Kingdom Archaebacteria • Prokaryotic • heterotrophs • Bacteria that live in extreme conditions • e.g. Bacteria in volcanoes

22. Kingdom Eubacteria • Simple organisms lacking nuclei (prokaryotic) • Either Heterotrophs or autotrophs • Can reproduce asexually • Bacteria that are found everywhere • E.g. E. coli

23. Kingdom Protista • Found many places, some terrestrial, some aquatic • Some have chloroplasts • Most are single celled. • Some are autotrophs, some Heterotrophs, some both • Reproduce sexually and asexually • e.g. Amoeba, Paramecium

24. Kingdom Fungi • Similar to plants but unable to carry out photosynthesis • Heterotrophs • Most are multicellular • Have cell walls but not made of cellulose • Reproduce sexually and asexually • Most are terrestrial • e.g. Yeasts, moulds, mushrooms

25. So… How do we classify???

26. Dichotomous Classification KeysChoose your own adventure! • Used to help place organisms into appropriate groups. • Each key includes two choices for each characteristic. • No two keys are the same. • WARNING…Do not classify based on the behavior of the organisms…just their structure!

27. A Classification Tree of the Six Kingdoms: All Living Organisms Prokaryotic? YES NO Live in harsh environment? Eukaryotic cells: Are they multi-cellular? NO YES YES NO Protista Archaebacteria Eubacteria Cell Wall? YES NO Animalia Wall of Cellulose? NO YES Plantae Fungi

28. YOU TRY IT!! • Make a classification tree using 10 items! • When done, exchange with someone else and see if it works! • If totally done… Try Text Activity!!!