Prokaryotes: Bacteria & Archaea
Name:
Bacteria, which outnumber all eukaryotes combined, differ from eukaryotes in at least seven ways.
Membrane-Bound Organelles: Bacteria are prokaryotes. Unlike eukaryotes, prokaryotes lack a cell nucleus and all other
membrane-bound organelles. Prokaryotes do contain ribosomes, granules of stored nutrients, enzymes, and certain
internal structures, however.
Cell Size: Most bacterial cells are about 1 µm in diameter; most eukaryotic cells are more than 10 times that size.
Multicellularity: All bacteria are single cells. Some eukaryotes are single-celled, but most are multicellular.
Chromosomes: Bacterial chromosomes consist of a single circular piece of DNA. Eukaryotic chromosomes are linear
pieces of DNA that are associated with proteins. Prokaryotes also have plasmids, small extra loops of DNA.
Reproduction: Bacteria reproduce by binary fission, a process in which one cell pinches into two identical cells. In
eukaryotes, however, microtubules pull chromosomes to opposite poles of the cell during mitosis. Afterward, the
cytoplasm of the eukaryotic cell divides in half, forming two cells.
Flagella and Pili: Bacterial flagella are simple structures that spin like a corkscrew to move the cell. Eukaryotic flagella
are more-complex structures made of microtubules that whip back and forth rather than spin. Some bacteria also have
short, thin, protein tubes called pili that attach to surfaces or to other cells.
Metabolic Diversity: Bacteria have diverse metabolic abilities. For example, some bacteria get their energy from sunlight
through photosynthesis. Others get energy from inorganic molecules that contain sulfur or nitrogen. Most bacteria get
nutrients and energy by feeding on other organisms.
In the space provided, write the letter of the phrase that best completes the statement.
1. Write 3 things that describe the characteristics of prokaryotes.
You can copy any 3 pieces of information from above.
To the left of the number, write E if the characteristic describes only eukaryotes, B if the characteristic describes only bacteria, or
EB if the characteristic describes both eukaryotes and bacteria.
2. B
3. B
4. E
5. EB
6. B
7. E
8. B
9. EB
10. E
11. EB
12. EB
13. EB
14. E
15. E
16. B
17. E
18. B
19. EB
20. B
21. EB
22. B
23. B
24. EB
2. reproduce by binary fission
3. lack a cell nucleus
4. chromosomes are linear pieces of DNA
5. have pili for attaching to surfaces and other cells
6. have plasmids
7. divide by mitosis
8. most cells are about 1 µm in diameter
9. single cells
10. cytoplasm contains membrane-bound organelles
11. simple flagella spin like a corkscrew
12. are about 10 µm in diameter
13. flagella are complex structures made of microtubules
14. most are multicellular
15. during cell division, microtubules pull chromosomes to opposite poles
16. cytoplasm lacks organelles
17. lack plasmids
18. some get energy from inorganic molecules that contain sulfur or nitrogen
19. two identical cells form when cytoplasm pinches in half
20. chromosomes consist of a single circular piece of DNA
21. have ribosomes
22. have a single chromosome called a nucleoid
23. have a cell wall made of peptidoglycan
24. have enzymes for performing metabolic activities
25. How do the sizes compare between virus, bacteria, and eukaryotic cells?
Virus < bacteria < eukaryotic cells
26. (Underline)Escherichia coli are [Gram-negative / Gram-positive] eubacteria.
27. (Underline) [Conjugation / Transduction] is a process in which two bacteria exchange genetic material.
28. (Underline)Escherichia coli have [pili and flagella / only flagella].
29. (Underline)Many bacteria move with [flagella / pili].
30. Complete the chart.
Define
Photoautotrophic
Another way of saying photosynthesis. Using
sunlight to create organic compounds.
Chemoautotrophic
Obtain their own energy by oxidizing inorganics
(like hydrogen sulfide)
Heterotrophic
Technically, obtain the carbon necessary for
energy production from organic molecules like
glucose, have to consume to get access.
Eukaryotic, prokaryotic, or both
Both (plants & many bacteria)
Prokaryotic
Both
In the space provided, write the name of the metabolic group—photoautotrophic, chemoautotrophic, or
heterotrophic—to which each of the following types of bacteria belongs.
___ photoautotrophic ____ 31. Cyanobacteria
____ photoautotrophic ____ 32. purple sulfur bacteria
____ chemoautotrophic ____ 33. bacteria that form their own proteins from hydrogen-rich chemicals like H2S
_____ photoautotrophic ___ 34. Anabaena
_____ heterotrophic ___ 35. Rhizobium
36. The two domains of prokaryotes are called ___eubacteria (Monera)__ and ___archaebacteria___.
37. Bacteria often have small extra loops of DNA called ___Plamsids___.
38. The cell wall of bacteria contains a protein-carbohydrate compound called ____peptidoglycan or
glycoprotein___.
39. Gram-negative bacteria are more resistant to medicines because they have a(n) ___thicker cell wall
_________.
40. Some bacteria can survive harsh conditions by forming thick-walled __endospore______.
41. List and describe 1 beneficial bacteria.
Nitrifying bacteria – metabolize inert atmospheric nitrogen into usable forms
Flora – help hosts metabolize certain substances (E.coli help us make vitamins B & K)
42. List and describe 1 harmful bacteria (not anthrax).
Staphylococcus – food poisoning
See pg 447 of blue book or pg 351 in grayple (grey-purple) book for list
43. Describe anthrax and explain the concern with it.
Anthrax produces lethal poisons when active but can be dormant as very tough spores. Because of its
resilience and other characteristics (odorless), it has been used as a source of bioterrorism.