CH 17-25- Organizing Life’s Diversity

1. CH 17-25- Organizing Life’s Diversity Unit 6

2. Classification- grouping of objects or information based on similarities • Taxonomy- branch of biology that groups and names organisms based on studies of their different characteristics

3. Bozemanbiology • Classification of life • http://www.youtube.com/watch?v=tYL_8gv7RiE

4. Binomial nomenclature • Carolus Linnaeus 1707-1778 • First word is genus (plural, genera). Capitalized • Second word is specific epithet. Not capitalized. • Underlined or italics

5. Scientific names and common names • Page 445

6. Taxonomic rankings • Kingdom • Phylum • Class • Order • Family • Genus • species

8. Taxonomic domain • Bozeman Biology Domains podcast • http://www.youtube.com/watch?v=wGVgIcTpZkk

9. Six kingdoms • Eubacteria • Archaebacteria • Protists • Fungi • Plants • animals

10. Dichotomous Key • Shark key • Create your own key

11. Bozemanbiology: viruses • http://www.youtube.com/watch?v=L8oHs7G_syI

12. viruses • Considered non living • Do not exhibit all the criteria for life • They do not carry out respiration, grow, or develop • All they can do is replicate. Must have a host cell • Named for organ or tissue they infect

13. Virus structure • Inner core of nucleic acid- either DNA or RNA • Outer protection coat called a capsid

14. Viral attachment • Must attach to host cell before it can enter it • Attaches to host receptor site (shape specific) • Each virus can usually attach only to a few kinds of cells • Example: small pox (page 478) • Exception: flu (page 478)

15. Viral replication cycle • Attaches to host, recognized, enters, then takes over the host metabolism • Only NOW can the virus replicate • Two types of viral replication: • Lytic cycle • Lysogenic cycle

16. Lytic cycle of viral replication • Once inside the host cell, a virus’s genes are expressed and the substances that are produced take over the host cell’s genetic material • Viral genes alter the host cell to make new viruses • Copies of viral genes burst from the host cell, killing the host cell

17. Lysogenic cycle • Not all viruses kill the cells they infect • Viral DNA integrated into host DNA • Now called a “provirus” • A provirus may not affect the functioning of its host cell, which continues to carry out is own metabolic activity • Every time the host cell reproduces, the provirus is replicated • Therefore, every cell that originates from an infected host cell has a copy of the provirus • This can last for many years • Enters lytic cycle at any time and will kill the cell

18. Provirus diseases page 480 • Cold sores (caused by herpes simplex I) • Herpes simplex II • Hepatitis B • Chicken pox

19. Retroviruses page 481 • HIV • RNA viruses • Reverse transcriptase • Figure 18.5 • HIV page 482

20. Bozemanbiology viral replication • http://www.youtube.com/watch?v=EqK1CYYQIug

21. prokaryotes • Kingdoms Archaebacteria and Eubacteria • Has cell wall, capsule, chromosomes, and ribosomes. Some have pilus and flagellum • Reproduce by binary fissionor conjugation (pages 489-490)

22. Archaebacteria • Archaebacteria- live in extreme environments. Swamps, deep ocean hydrothermal vents, seawater evaporating ponds. Oxygen free environments

23. Eubacteria • Eubacteria are prokaryotes that live in places more hospitable than archaebacteria • 5000 species • Use organic molecules as a food source • Some cause diseases but most are harmless. Some are actually helpful • Saprophytes- organisms that feed on dead organisms or organic wastes

24. Some are heterotrophs • Saprophytes- organisms that feed on dead organisms or organic wastes

25. Some are photosynthetic • Cyanobacteria- use chlorophyll to trap sun’s energy. live in ponds, streams, and moist areas of land

26. Some are chemosynthetic autotrophs • Do not obtain energy from sun. • They break down and release the energy of inorganic compounds containing sulfur and nitrogen in a process called chemosynthesis. • Convert atmospheric nitrogen into the nitrogen-containing compounds that plants need

27. A typical Bacterial Cell Structure • Page 487 • Capsule • Cell wall • Chromosomes • Plasma membrane • Pilus • Plasmid • flagellum

28. Identifying bacteria • By shape • Spheres (cocci) • Rods (bacilli) • Spirals (spirilla)

29. Cocci

30. bacilli

31. Spirilla

32. Bacteria microscope lab

33. Bacteria reproduction- binary fission • No mitosis because no nucleus • Binary Fission- asexual form • 1. copies chromosome • 2. chromosomes attach to cell membrane • 3. cell grows • 4. cell splits • RAPID. Can reproduce every 20 minutes, producing enormous numbers very quickly

34. Bacteria reproduction- conjugation • Sexual form • One bacteria transfers all or part of its chromosome to another cell through a bridge like structure called a pilus (pili) • Afterwards, bacteria undergoes binary fission

35. Diversity of metabolism • Obligate aerobes • Obligate anaerobes

36. endospore • Tiny structure that contains a bacterium’s DNA and a small amount of its cytoplasm, encased by a tough outer covering that resists drying out, temperature extremes, and harsh chemicals. • When environmental conditions improve, the endospore germinates or produces a cell that begins to grow and reproduce • To kill endospores, temperature must exceed 100 degrees C (boiling point of water). Must sterilize in pressure cooker or antoclave

37. Problem solving 18.2 • Page 492

38. Importance of bacteria • Nitrogen fixation • Recycling of nutrients • Food and medicines • Bacteria cause disease

39. Biolab page 498

40. Virtual bacteria lab • Glenco • D:\biology powerpoints\organization of life\Virtual Lab- bacteria.mht

41. Protists- ch 19 • Kingdom Protista • Eukaryotes and unicellular • Lacks complex organ systems and lives in moist environments • Some are autotrophs and some are heterotrophs (saprophytes) • Some reproduce sexually, some asexually • Some have cilia (“ciliates”), some flagella (“flagellates”), some pseudopodia (page 504)

42. Paramecium Feeding Video 34 sec • http://www.youtube.com/watch?v=a4aZE5FQ284

43. Pseudopodia- extensions used to move • “cytoplasmic extensions of the plasma membrane”

44. Pseudopodia video 44 sec • http://www.youtube.com/watch?v=pvOz4V699gk

45. Four main groups of protozoans • 1. amoebas • 2. flagellates-have one or more flagella • 3. ciliates-use cilia to move • 4. sporozoans-produce spores

46. Amoebas

47. Flagellates

48. ciliates • Page 507- diagram

49. sporozoans

50. Parasitic protozoans and Malaria • Protists in the Phylum Sporozoa are called sporozoans • Reproduce by spores • Internal Parasites • Plasmodium causes malaria • Transmitted by mosquitos • Page 509