Unit 2 Microbiology Quiz

At the start there are 3 bacteria cells, they divide every 10 minutes. How many cells will there be after culturing them for 7 hours?

• 1,344

• 2,378

• 7,890

• 1,567

If 1 mL sample form tube #1 with a tube dilution of 1/25 is placed in tube #2 with 24 mL of diluent, what is the tube dilution and what is the final dilution of tube #2?

• tube dilution 1/50

• tube dilution 1/25

• final dilution 1/625

• final dilution 1/50

This type of media contains specific ingredients that help us to visually distinguish which species do or do not carry out a specific biochemical process.

• selective media

• differential media

• chemically defined media

• enrichment culture media

This media selects for gram-negative organisms and isolates lactose fermenters (pink) and non-lactose fermenters (clear).

• chocolate agar

• Mannitol salt agar

• Eosin-methylene blue (EMB) agar

• MacConkey agar

This is a general purpose medium that supports the growth of a wide variety of bacteria.

• blood agar

• nutrient agar

• chocolate agar

• MacConkey agar

When streaking a plate, the loop should be flamed

• At the beginning and end 
•  At the beginning and end and between the first 2 zones 
• At the beginning and end and between the second and third zone 
• At the beginning and end and between each zone 

What is the function of the Z ring in binary fission?

• What is the function of the Z ring in binary fission?

• It forms a contractile ring at the septum.

• It separates the newly synthesized DNA molecules

• It mediates the addition of new peptidoglycan subunits.

. Quorum sensing is used by bacterial cells to determine which of the following?

• the density of the population

• the availability of nutrients

• the size of the population

• the speed of water flow

Tags

NGSS.HS-LS2-2

Pseudomonas aeruginosa is a common pathogen that infects the airways of patients with cystic fibrosis. It does not grow in the absence of oxygen. The bacterium is probably which of the following?

• an aerotolerant anaerobe

• an obligate aerobe

• an obligate anaerobe

• a facultative anaerobe

Tags

NGSS.HS-LS2-3

Bacteria isolated from Lake Natron, where the water pH is close to 10, are which of the following?

• alkaliphiles

• facultative anaerobes

• neutrophiles

• obligate anaerobes