Chapter 11 Microbiology

Question 1

What term for a bacterial cell shape means a curved rod? ..a stiff spiral? ..a flexible spiral? ..variable shape? ..a short fat rod?

Answer 1

–	Curved Rods are vibrios
–	A stiff spiral is spirilla
–	A flexible spiral is coccobacillus
–	A variable shape is pleomorphic
–	A short flat rod is bacillus

Question 2

Which 2 factors affect the arrangement of prokaryotic cells?

Answer 2

– Planes in which cells divide

– Separation of daughter cells

Question 3

. Why do bacilli have fewer arrangements of their cells than do coccal cells? What is a chevron shape?

Answer 3

– because bacilli divide transversely/perpendicular to long acis; daughter bacilli separate to become single cells or stay attached as either pairs or chains

Question 4

What is the most common means of asexual reproduction in prokaryotes? What are 4 less common means of asexual reproduction in prokaryotes?

Answer 4

– Binary fission (most common)

– Also snapping division, spore formation, budding, or fragmentation

Question 5

What are 2 similarities between binary fission and budding?

Answer 5

– They are both forms of asexual reproduction

– Replicated DNA

Question 6

. What is 1 difference in the outcomes of binary fission and budding?

Answer 6

– Major difference between binary fission and budding is that in budding there is an outgrowth from the parent individual producing a bud, which is identical to its parent individual, but in binary fission, there is no bud or outgrowth formation. It only results in two identical individuals by splitting the parent cell into two parts with mitotic cell division followed by cytokinesis.

Question 7

Which group of bacteria is most ancestral to other bacteria?

Answer 7

– Aquifex

Question 8

Describe the primitive earth environment at the time of the earliest bacteria.

Answer 8

– Very hot habitats containing little oxygen; hot, acidic, anaerobic, and exposed to intense ultraviolet radiation from the sun

Question 9

What are the 2 largest groups of Gram negative bacteria? ..of Gram positive bacteria?

Answer 9

– Gram Negative – Cyanobacteria & Nitrogen fixing bacteria
– Gram Positive – Firmicutes & Actinobacteria

Question 10

What are 3 major groups within the Firmicutes?

Answer 10

1. Clostridia
2. Mollicutes
3. Bacilli

Question 11

What are 3 major contributions of cyanobacteria to the modern world?

Answer 11

1) produced O2;
2) reduced N2 → NH3 (ammonia)
3) gave rise to algae and plant chloroplasts

Question 12

What is the genus of the bacterium that can cause a UTI or external otitis?

Answer 12

– Pseudomonas

Question 13

What is the genus of the firmicute bacterium that contaminates dairy products and causes listerosis?

Answer 13

– Listeria: contaminates milk and meat products

Question 14

What is the genus of the Gram negative bacterium that has a curved rod and causes cholera?

Answer 14

– Vibrio

Question 15

Name one genus of N fixing bacteria that colonizes the roots of legume plants.

Answer 15

– Rhizobium

Question 16

What is the function of nitrifying bacteria and where would you find them?

Answer 16

– Nitrifying bacteria: convert NH3 to NO2- (nitrite) and NO3- (nitrate)
– Nitrobacter, soils, lakes, sewage plants

Question 17

Which firmicute bacterium has cocci in clusters and can cause a variety of diseases such as skin diseases, food poisoning, and toxic shock syndrome?

Answer 17

– Staphylococcus

Question 18

Which Gram negative bacteria are intracellular pathogens that cause respectively Q fever and Legionnaire’s disease?

Answer 18

– Q fever is coxiella

– Legionnaire’s disease is legionella

Question 19

Which spirochaete bacterium causes syphilis?

Answer 19

– Treponema

Question 20

Which firmicute bacterium forms endospores and causes tetanus?

Answer 20

– Clostridium

Question 21

Which actinobacterium is the source of many antibiotics and can sometimes cause sinusitis?

Answer 21

– Streptomyces

Question 22

Which actinobacterium has waxy cell walls and causes tuberculosis?

Answer 22

– Mycobacterium

Question 23

Which family of Gram-negative bacteria are facultative anaerobes that live in our intestine and are often the cause of gastroenteritis?

Answer 23

– Campylobacter

Question 24

What is a microbial antagonist?

Answer 24

– The inhibition of one bacterial organism by another. Through microbialantagonism, the normal bacterial flora of the body provides some defenseagainst disease-causing organisms.