1. Unit 10: STERNGRR and Kingdoms
p. 155
“Simple” Organisms
Unit 10: STERNGRR and Kingdoms

2. Is a virus a living thing?
p. 155
Is a virus a living thing?
Viruses, although not technically living due to the lack of cellular structure, are classified as microorganisms.

3. Why are Viruses Nonliving?
Living Cell
Virus
Asexual or sexual
DNA
Yes
Reproduction- only with a host cell
Genetic code- DNA or RNA
Growth/ development- NO
Obtain and use energy- NO
Response to environment- NO
Change overtime- Yes

4. Is a virus a living thing?
Viruses are composed of a protein coat (called a capsid) that protects a nucleic acid - either DNA or RNA.
The shape of the capsid determines the type of cell the virus can infect.

5. Is a virus a living thing?
A virus can only exist by infecting a host cell.
Viruses are classified by the reproductive cycle it uses to infect the host cell.

6. Fill It In …
Name 2 reasons that viruses are not considered living things: 1. 2.

7. Is a virus a living thing?
1. The lytic cycle describes the “life cycle” in which a virus uses the host cell to make copies of itself, then quickly kills the host cell as new virus copies are released.

8. Lytic Cycle Make copies of itself and infect host cell
Lytic Cycle
Make copies of itself and infect host cell
Cell cannot tell the difference between virus’ DNA and its own
Will transcribe and translate viral DNA
Viral DNA and protein will eventually chop and KILL the host cell
Only after hundred of copies of the virus was made

9. Is a virus a living thing?
2. The lysogenic cycle describes the “life cycle” in which the virus has a dormant stage in which the virus remains inactive within the cell.
This dormant period may last for weeks, months, or years.
An environmental trigger may cause the viral DNA to emerge from the host DNA and begin a lytic cycle of reproduction.
Ex: Herpes and chicken pox viruses!

10. Lysogenic Will integrate itself into the host DNA
Will remain dormant for some time
It will eventually replicate itself along with the host DNA
Watch this video: Virus

11. Fill It In …
Using the diagram, explain how lytic and lysogenic are different:

12. Watch this video: How a virus works

13. Is a virus a living thing?
Viruses are pathogenic, or disease-causing microorganisms

14. Is a virus a living thing?
HIV causes AIDS.
HIV infects T-cells, which are important for the immune response.
Thus, people with AIDS often die of opportunistic infections, such as pneumonia.

15. Is a virus a living thing?
Several different viruses cause influenza (the “flu”).
The influenza viruses mutate rapidly, meaning the actual virus being spread changes with each outbreak.

16. Is a virus a living thing?
Flu epidemics are caused by viruses that are genetically different enough from earlier years’ viruses that people have little immunity to them.

18. Is a virus a living thing?
Influenza viruses infect respiratory cells.
The lysis of these cells leads to some of the typical symptoms of the flu, such as sore throat and congestion.

19. Is a virus a living thing?
A poxvirus causes smallpox.
Special efforts have eradicated the smallpox disease; however samples of the smallpox virus were kept for study and are currently stored at the CDC in Atlanta.

20. Is a virus a living thing?
Smallpox starts in the cells of the lymph nodes and lungs, then moves into other internal organs and the skin.
Symptoms include severe headaches, muscle ache, and pustules on the skin.

21. Virus Prevention and Treatment
Vaccines can be developed for viral diseases. A vaccine uses a dead or weakened form of the virus to “turn on” the immune response so that antibodies are produced.

22. Virus Prevention and Treatment
Active immunity to a virus is conferred by a vaccine or by exposure to the virus itself.
Production of antibodies by an organism after an encounter
Natural- Due to infection
Artificial- Vaccination

23. Virus Prevention and Treatment
Passive immunity is conferred when antibodies are passed between individuals (ie. through breast milk).
Acquire antibodies from another organism
Natural- pass from mother to child during placenta or breast milk
Artificial- Immune serum or antivenin

24. Virus Prevention and Treatment
Antiviral medications work by interrupting the virus’s life cycle.
Antibiotics are NOT effective against viruses!

25. Viruses and Natural Selection
Viruses often mutate rapidly, meaning the actual virus being spread changes with each outbreak.

26. Viruses and Natural Selection
2.Mutations in the HIV virus make developing a treatment or vaccine difficult. Viruses that are resistant due to mutations can survive and reproduce by natural selection.
3.Flu epidemics are caused by viruses that are genetically different enough from earlier years’ viruses that people have little immunity to them.

27. Fill It In …
Identify 3 viral diseases: 1. 2. 3.

28. Check Yourself! What are the two parts of a virus?
What are the two reproductive cycles of viruses?
What is a pathogen?
What type of cell does HIV infect?
Why is there a different flu virus each year?

29. Are all bacteria “bad”?
A. All bacteria are classified in the kingdoms Eubacteria and Archeabacteria.
They are differentiated by the chemicals found in the bacterial cell wall.
They are all unicellular and prokaryotic.

30. Are all bacteria “bad”?
B. Bacteria typically reproduce through binary fission, but can also exchange DNA in a process known as conjugation.
This allows for genetic variation in a bacterial population.

32. Are all bacteria “bad”?
C. The vast majority of bacteria in our world are beneficial.
They are important decomposers and perform many other ecosystem services.
They exist in the intestines of some animals and aid digestion.
They are also important in food production.

33. Are all bacteria “bad”?
D. Some bacteria are pathogenic. One example is the bacterium Mycobacterium tuberculosis, which causes tuberculosis (or TB). The disease attacks the lungs and causes coughing, chest pain, fatigue and fever – it can be fatal if not treated. This bacterium causes disease because it destroys cells. The cells are broken down by the bacteria as a source of nutrition. Other bacteria harm the host by releasing toxins such the bacterium that causes food poisoning.

34. Are all bacteria “bad”? Bacteria
E. Pathogenic bacteria can be treated with antibiotics. Antibiotics kill the bacteria by destroying the cell wall. Bacteria that are resistant to antibiotics can survive and reproduce by natural selection. This means that new antibiotics must continually be developed.
Bacteria

35. Fill It In …
Identify 3 ways that bacteria are beneficial: 1. 2. 3.

36. Are all bacteria “bad”?
Other bacteria harm the host by releasing toxins such as the bacterium that causes food poisoning.

37. Check Yourself! Which two kingdoms include bacteria?
How do bacteria reproduce?
Name two ways that bacteria cause illness.

38. What is a protist?
Protista is a diverse kingdom of organisms that is divided into 3 main groups:
Algae (plant-like)
Protozoa (animal-like)
Slime molds (fungus-like)

39. What is a protist?
Algae are important aquatic producers (the base of aquatic food webs) and produce most of earth’s oxygen.
They may be unicellular or multicellular (seaweed).

40. What is a protist?
Protozoa are unicellular, aquatic protists that are similar to animals.
Protozoa have adaptations that allow them to accomplish life functions:

41. What is a protist?
Adaptations for movement include a whiplike tail called a flagellum, tiny hair-like projections called cilia, or extensions of the cell membrane called pseudopodia.

42. What is a protist?
An adaptation for water balance is the contractile vacuole.
This vacuole pumps excess water out of the cell, since these aquatic organisms may take in more water than necessary by osmosis.

43. What is a protist?
An adaptation for response to stimuli is the eyespot.
This structure allows for responses to light (movement toward or away).

44. Watch! Single Celled Organisms
What is a protist?
In protozoa, reproduction is asexual through binary fission.
Some protists may exchange DNA through conjugation.
Watch! Single Celled Organisms

45. What is a protist? Some protists are pathogenic.
Malaria is a disease caused by parasitic protists called plasmodia.
Malaria is transmitted by a mosquito.
Any organism which transmits/carries a disease without being affected by the disease is called a vector.
Watch! Malaria in human
Malaria in a mosquito

46. What is a protist?
The symptoms of malaria include headache, shaking, chills, and fever.
Some forms of malaria lead to comas, convulsions, or even death.

47. Check Yourself! What are the 3 groups of protists?
Name 2 reasons that algae are important.
What protist causes the disease malaria?

48. What do fungi look like?
mushrooms
mold
yeast

49. Cellular Biology of Fungi
Eukaryotic
Heterotrophic
Have mitochondria; NO chloroplast!
Sexual and Asexual Reproduction
Multicellular (but yeasts are unicellular)

50. How are fungi different from plants?
Fungi are eukaryotic organisms that may be unicellular or multicellular.

51. Remember, they are HETEROTROPHS!
Fungi Nutrition
Cellular Respiration!
C6H12O O2  ATP H2O CO2
Glucose
Oxygen
Energy
Water
Carbon dioxide
Remember, they are HETEROTROPHS!

52. Alcoholic Fermentation
Anaerobic Respiration = NO OXYGEN REQUIRED
Glucose + (NO Oxygen)  Alcohol + Carbon dioxide
This is how we use yeast to ferment beer and make it alcoholic.
This is also what makes bread rise.

53. How do they do it? They secrete ENZYMES!
What about those fungi that are decomposers?

54. How are fungi different from plants?
Fungi are heterotrophic.
They obtain food through extracellular digestion, secreting digestive chemicals and absorbing nutrients across the cell wall.

55. Let’s watch a short animation to see how fungi reproduce

56. Sexual or Asexual Reproduction?
Cells go through (mitosis / meiosis?
Gamete + Gamete  Zygote
Cells go through (mitosis / meiosis?

57. More Reproductive Modes
Sexual !
Asexual !
Producing Spores (sporulation)
Fission

58. How are fungi different from plants?
Fungi may reproduce asexually, such as budding in yeast
Spores may be used in sexual or asexual reproduction.

59. Fill It In …
List 2 ways that fungi can reproduce: 1. 2.

60. How are fungi different from plants?
Some fungi are pathogenic.
Candida is a yeast (fungus) that is one of the normal inhabitants of moist human epithelial tissue, such as the throat and vagina.

61. How are fungi different from plants?
Certain circumstances (such as change in pH or sudden decrease in helpful bacteria) can cause Candida to become pathogenic by growing too rapidly and releasing harmful substances.
The condition caused by this growth is called candidiasis.
Candidiasis leads to oral thrush, yeast infections, and/or kidney infections.

62. Penicillin Humans and Fungi have an amazing history!
Penicillin (an antibiotic produced by a fungus) was discovered accidentally by Alexander Flemming

63. Scientific name?

64. More on the Evolution of Fungi!
According to this cladogram, which type of fungus evolved first?
Which type of fungus is the youngest (most recent to evolve)?
What derived characteristic separates the Chytridiomycota from the Zygomycota?
Chytrids
Club fungi (mushrooms!)
Loss of flagella

65. Check Yourself! How do fungi obtain food?
What reproductive structure can be used for sexual or asexual reproduction?
What is the name of the fungus that causes thrush?

66. Problem Solving Answer the questions on pp. 161-162 in your handbook.
Show your teacher your completed HB pages ( ) when you finish and receive your grade for today’s lesson.