Week 2, Session 1
Chapters 26-27
Important text sections: 26.1, 26.3, 26.6, 27.1, 27.2,
Supplemental Instruction
IowaStateUniversity / Leader: / Kelsey
Course: / Bio 211
Instructor: / Dr. Holscher
Date: / 8-31-09

Phylogeny

  1. Who first developed the binomial nomenclature system? Carolus Linneaus
  1. What are the two components of the binomial nomenclature format?

genus and species

  1. Give an example of this format:

homo sapiens

Cladistics

  1. What is the primary criterion in the methodology of cladistics?

Common ancestry is the primary criterion used in cladistics.

  1. A true clade is:
    a. monopyletic
    b. paraphyletic
    c. polyphyletic
  1. Draw an example of a clade:

Three Domain System

  1. What are the domains are found in the three-domain system?

Eukarya

Bacteria

Archaea

Characteristics of Prokaryotes

1. List four characteristics of prokaryotes:

able to live in extreme environments

first organism on earth

unicellular

have a diameter of around 0.5-5 micrometers

2. Name and draw the three common shapes of prokaryotes:

Cocci (spherical) / Bacilli (rod-shaped) / Spriochetes (spiral)

3. A gram-positive__ bacteria has a thick cell wall made of peptidoglycan that causes it to appear purple_ during gram staining.

4. A gram-negative bacteria has a thin layer of peptidoglycan sandwiched between two membranes that causes it to appear _pink/red_ during gram staining.

5. Match the following prokaryotic cell structures with their function:
1. capsule __a__

2. fimbriae __c__

3. sex pili __d__

4. flagellum __b__

5. endospores __e__

6. List and describe the three ways in which prokaryotes perform genetic recombination:

Transformation / Transduction / Conjugation
A prokaryotic cell takes up foreign DNA from its surroundings. / Bacteriophages move bacterial genes from one host to a different host. / Two bacterial cells temporarily join and transfer the material between them.

7. Describe the four modes of nutrition in prokaryotes:

Photoautotrophs / Chemoautotrophs / Photoheterotrophs / Chemoheterotrophs
Use light energy to drive synthesis of organic compounds. / Oxidize inorganic substances to use as a carbon source. / Use light energy and must obtain carbon in organic form. / Must consume organic molecules for energy and carbon.

8. Write in the name of the oxygen-use type that matches the given definitions:

Obligate aerobe / Obligate anaerobe / Facultative anaerobe
Require oxygen for cellular respiration, cannot grow without oxygen. / Are poisoned by oxygen, cannot grow in the presence of oxygen. / Use oxygen if it is present but can also grow without oxygen.

9. What is the most important role that prokaryotes play in the biosphere?

Decomposers- break down corpses, waste, and dead plants which releases carbon and nitrogen.

10. Describe the four types of ecological interactions that exist between prokaryotes and other organisms:

Symbiosis:a relationship in which two species live in close contact

  • Mutualism: both species benefit
  • Commensalism:one species benefits, the other is neither harmed nor helped
  • Parasitism:a parasite eats the tissues or fluids of its host, which harms the host

Archaea

1. Name the three types of extremophiles, and describe their living conditions/preferences:

Halophiles / Thermophiles / Methanogens
Either tolerate or prefer highly saline environments. / Thrive in extremely hot environments. / Obtain energy by using carbon dioxide to oxidize hydrogen gas, releasing methane as a waste product.

Bacteria

1. True or false: All bacteria are pathogenic (harmful). _False

a. If this is false, give an example of a non-pathogenic (beneficial) type of bacteria:

Many are found in human intestines. We have a mutualistic relationship with these bacteria and depend on them to help digest some foods we eat.

2. __Exotoxins___ are poisonous illness-causing proteins secreted by bacteria and other organisms. An example of this type of toxin is _cholera_.

3. _Endotoxins______are components of the outer membrane of some types of bacteria that are released when the cell walls break down. An example of this type of toxin is _salmonella_.

4. List four ways in which bacteria and/or archaea are being used in research, technology, and industry today:

Food production- cheese and yogurt

Bioremediation- use of organisms to remove pollutants from soil, air, and water

Production of natural plastics

Modification of vitamins, antibiotics, and hormones