Bacteria/Archaea

Question 1

What are Bacteria?

Answer 1

They are Prokaryotes

Question 2

Pathogens

Answer 2

-cause diseases such as strep throat, salmonella poisoning, and tetanus

Question 3

Ecosystem

Answer 3

• essential for nutrient cycles

- fix nitrogen and produce oxygen

Question 4

Mutualistic relationships

Answer 4

-in human gut, produces vitamins k and B12

Question 5

Commercial use

Answer 5

• production of cheese, yogurt, soy, and chocolate

- produce antibiotics

Question 6

Six major Groups of Bacteria

Answer 6

• proteobacteria
• green bacteria
• cyanobacteria
• Gram-postive bacteria
• spirochetes
• chlamydias

Question 7

Plasmid

Answer 7

• a small loop of DNA often found in prokaryotic cells
• usually contains a few genes that can provide an advantage for the cell
• Eg. antibiotic resistance

Question 8

Bacterial Shapes

Answer 8

• coccus(round)
• Bacillus(rod-shaped)
• spirillum(spiral)
• Diplo(pairs)
• Staphylo(clusters)
• Strepto(chains)

Question 9

Nutrition

Answer 9

• Heterotrophic bacteria: break down organic chemicals from other living things to obtain carbon
• Autotrophic bacteria: make their carbon-containing molecules by assembling small inorganic molecules from the abiotic environment
• Photoautotrophs: use sunlight to produce energy(eg. cyanobacteria)
• Chemoautotrophs: use energy from chemical reactions

Question 10

Metabolism

Answer 10

• Obligate aerobes: oxygen is needed for survival(ex. M. tuberculosis)
• Obligate anaerobes: must be in a oxygen fee environment (ex. clostridium botulinum)
• Facultative anaerobes: Can live with or withought oxygen(escherichia coli)
• when 02 is present aerobic respiration
• without O2 fermentation

Question 11

Reproduction

Answer 11

-Binary fission
-conjugation
-transformation
Horizontal gene transfer
-Endospore fomation

Question 12

Binary fission

Answer 12

• asexual reproduction
• one parent cells divides to form two daughter cells
• mistakes, or mutations, can occur when genetic material is being copied
• Fast reproduction= many mutations
• this leads to increased genetic diversity

Question 13

Conjugation

Answer 13

• sexual reproduction

- two cells join to exchange genetic information

Question 14

Transformation

Answer 14

-a bacterial cell takes in and uses pieces of DNA from its environment

Question 15

Horizontal gene transfer

Answer 15

-one species gets DNA from a different species

Question 16

Endospore formation

Answer 16

• occurs with gram positive bacteria
• when growth conditions become unfavourable the bacterium makes an endospore(a thick wall that surrounds its DNA and cytoplasm)
• The endospore can lie dormant for a long time, though drought, heat and radiation until good condition return.