MICROBE STUDY GUIDE
1. Why do we call them “microbes”?
We call them microbes because they are microscopic and you need a microscope to see them.
2. Was the 1st form of life on Earth a prokaryote or eukaryote?
Prokaryote (cyanobacteria)
3. Eukaryotes have a ****.
nucleus
4. Both prokaryotes and eukaryotes have ****.
DNA
5. Archaebacteria are also known as ****.
Extremophiles
6. Do bacteria have a nucleus?
no
7. Are bacteria prokaryotes or eukaryotes?
prokaryotes
8. What do we call Extremophiles that can tolerate salty environments?
Halophiles
9. What do we call Extremophiles that can tolerate extreme heat?
Thermophiles
10. Do viruses have DNA?
yes
11. Why are viruses NOT considered to be living organisms?
Viruses cannot survive and reproduce on their own and must find a host cell to complete their life cycle.
12. What are the four shapes of viruses?
Crystals, spheres, cylinders, and spacecraft
13. How do viruses reproduce? Viruses enter a host cell, reprogram the host cell’s DNA to copy and make more
of the virus. The host cell dies when new viruses are released.
14. How do viruses cause disease? Viruses reproduce in high numbers using the body’s host cells and cause
the immune system to weaken during their attack.
15. Do bacteria have DNA?
yes
16. Why are bacteria considered to be living organisms?
Bacteria can survive and reproduce on their own.
17. What are the three shapes of bacteria?
Bacilli (rod-shaped); Cocci (sphere-shaped); and Spirilla (spiral-shaped)
18. How do bacteria reproduce?
Bacteria reproduce by binary fission.
19. How do bacteria cause disease? Bacteria can reproduce extremely fast and overwhelm the body’s immune
system. “Bad” bacteria are called “pathogenic” bacteria.
20. Why do antibiotics work on bacterial infections but not viral infections? Antibiotics attach to the cell
membrane and viruses do not have a cell membrane on which the antibiotics can attach.
21. What are pathogens?
Pathogens are microrganisms that cause disease.
22. What are mutagens?
Mutagens can cause disease by creating harmful changes in the DNA.
23. What is a vector?
A host, such as an insect, that transmits a disease to a host. (Example: A mosquito transmitting malaria.)
24. What is a contagion?
A contagion is a disease that can be transmitted through direct (touching) or indirect (doorknob) contact.
25. In which eon of geologic time did the first form of life appear on Earth?
Archaean
26. In which eon of geologic time did the first plant-like and animal-like organisms appear on Earth?
Proterozoic
27. What are the 3 main divisions of protists?
Plant-like, animal-like, and fungus-like protists
28. How do different plant-like protists move?
Some plant-like Protists move with flagella (volvox) and others do not move.
29. How do plant-like protists get their food?
Plant-like protists produce their own food through photosynthesis.
30. How do plant-like protists reproduce?
Plant-like protists reproduce through asexual and sexual reproduction.
31. How do different animal-like protists move? Animal-like protists move using flagella, cilia, and pseudopods.
Some animal-like protists (spore-forming) do not move.
32. How do different animal-like protists get their food? Most animal-like protists move using flagella, cilia, or
pseudopodia to get their food. Some (spore-forming) cannot move and must use a host to locate their food
(Ex. Malaria).
33. How do different animal-like protists reproduce?
Animal-like protists reproduce through asexual (binary fission) and sexual reproduction.
34. How do different fungus-like protists move?
Water molds do not move; Slime can move using pseudopodia at certain times in their life cycle.
35. How do different fungus-like protists get their food?
Water molds rely on hosts for food; slime molds use their pseudopodia to find food.
36. What substance do fungus-like protists need in order to reproduce?
Fungus-like protists form spores to reproduce.
37. What is the difference between Autotrophs and Heterotrophs? Autotrophs capture and release energy
through photosynthesis; Heterotrophs capture and release energy through cellular respiration.
38. What is the difference between a producer, a consumer, and a decomposer? Producers are Autotrophs and
use photosynthesis to make their own food; Consumers are Heterotrophs and consume food from other
sources; Decomposers are Heterotrophs that break down dead material.
39. What is the chemical formula for photosynthesis?
6CO2 + 6H2O = light energy => C6H12O6 + 6H2O
40. What is the chemical formula for cellular respiration?
C6H12O6 + 6H2O => 6CO2 + 6H2O + energy (ATP)
41. What does an eyespot do?
An eyespot is used to sense or detect light waves and assists Autotrophs in finding light for photosynthesis.
42. What does a contractile vacuole do?
Contractile vacuoles hold excess water and nutrients and contract to release them from the cell or organism.
43. What important information is stored inside the nucleus of a eukaryotic cell?
DNA
44. What important information is stored inside the cell of a virus or prokaryotic cell?
DNA
45. Draw an example of a protist with flagella.
46. Draw an example of a protist with cilia.
47. Draw an example of a protist with pseudopodia.
48. Draw an example of a protist that lives in a colony.
49. Draw a protist to illustrate endocytosis.
50. Draw a protist to illustrate exocytosis.