On The Edge Of Life CH11

Question 1

List three beneficial bacterial species and where they are found.

Answer 1

• Lactobacillus in yogurt
• E. Coli in digesting food
• rhizobium legume fixing nitrogen

Question 2

Three facts about Archaea:

Answer 2

• Were first described in 1970s
• Are known as extremophiles because they are found living in extremely harsh environments.
• Differ from bacteria in the composition of cell wall and plasma membrane.

Question 3

What of the following is not true about bacteria?
1. Bacteria are prokaryotic
2. Bacteria have membrane-bound organelles
3. Oxygen requirements vary from obligate aerobe to obligate anaerobe
4. Bacteria exhibit a number of nutritional modes.
5. Both 2 and 4.

Answer 3

5.

Question 4

Cyanobacteria were formerly described as…?

Answer 4

Blue-green algae and are single called or colonial

Question 5

Cyanobacteria occur where?

Answer 5

Aquatic environments, sidewalks, and trees; they also use an autotrophic mode of nutrition.

Question 6

What is the function of the following in bacteria?
Cell wall:
Plasma membrane:
Plasmid:
Nucleoid:
Pili:

Answer 6

Cell wall: Protection and shape

Plasma membrane: Provides support & regulates material movement in and out of bacteria

Plasmid: Produces copies of genetic material and ensures survival

Nucleoid: Controls activity and reproduction

Pili: Movement, adherence, and attachment.

Question 7

Describe the three major shapes of bacteria, and give an example of each.

Answer 7

Bacilli/Rod-Shaped: Rod shaped to oval and similar to a coccus. E. coli
Spirilli: Spiral or corkscrew shaped. Treponema Pallidum
Cocci: Circular sometimes producing grape like clusters. Staphylococcus

Question 8

5 safety factors to consider when working with bacteria.

Answer 8

• Clean/disinfect work space
• wash hands
• Avoid cross contamination
• follow sterile techniques & procedures
• Follow instructions to clean & put away equipment