FREE BIOLOGY AND STUDY GAMES ABOUT MICRO CHAPT.

PDF Download

FREE BIOLOGY AND STUDY GAMES ABOUT MICRO CHAPT.

4 EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -67 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation

Question 1: phase where primary metabolites are produced

Answer:

exponential phase Question 2: The nitrogen in microorganisms will typically be present in what molecules?

Answer:

Protein - also present in nucleic acids.

Question 3: A differential medium

Answer:

contains a substance that certain bacteria change in a recognizable way; examples include blood agar and MacConkey agar

Question 4: The most probable number (MPN) method

Answer:

is a statistical assay based on the theory of probability and is used to estimate cell numbers

Question 5: uses passage of a measured amount of very dilute culture and estimates the number of cells by placing filter on a plate

Answer:

Filtration Question 6: A growth medium that can discriminate between two different bacterial species based on an observed change in the media is termed

Answer:

a differential medium Question 7: Where measured culture is serialy diluted and measured in small ammount and then poured onto plate & incubated

Answer:

Spread plate method

Question 8: How is ATP is detected

Answer:

by employing luciferase, which uses ATP to produce light.

Question 9: Secondary metabolites are normally produced during

Answer:

stationary phase

Question 10: an enrichment media for chemolithotrophs

Answer:

You grow an organism in media containing H2S and CO2 as the only sources for energy and carbon

Question 11: Most bacteria are neutrophiles so what would their ph level be?

Answer:

within the pH range of 5 to 8

Question 12: Acidophiles grow optimally

Answer:

ph below 5.5

Question 13: Direct Cell Counts

Answer:

Do not distinguish between living and dead cells.

Question 14: A method that counts only live microbes is the

Answer:

plate count

Question 15: complex & differentail media

Answer:

can tell growth from one organisin from another

Question 16: A chemically defined medium

Answer:

is composed of precise mixtures of pure chemicals; an example is glucose-salts medium.

Question 17: Degermination

Answer:

removal of pathogens from skin with chemicals

Question 18: Chemoautotrophs

Answer:

use inorganic compounds for energy and derive their carbon from CO2

Question 19: the exponential or log phase

Answer:

the cells divide at a constant rate. Initially these bacteria synthesize primary metabolites, but they begin synthesizing secondary metabolites in the late log phase Question 20: Why would bacteria be more susceptible to antibiotics during log phase?

Answer:

because bacteria are multiplying rapidly and most metabolic systems are active. When a metabolic system is active, it is most susceptible to antibiotic action

Question 21: A differential media is used to

Answer:

isolate a specific organism or group of organisms

Question 22: unpaired electrons

Answer:

dangerous

Question 23: death phase

Answer:

The total number of viable cells in the population decreases at a constant rate during the death phase.Question 24: If the solute concentration is higher in the medium than in the cell

Answer:

water diffuses out of the cell, causing plasmolysis.

Question 25: How can Gas production can be detected in blood cultures

Answer:

by using a molecule that fluoresces more brightly when the pH changes slightly or by using an inverted tube in culture media to trap gas.

Question 26: pH indicators

Answer:

can be used to monitor acid production

Question 27: enrichment culture

Answer:

provides conditions in a broth that enhance the growth of one particular organism in a mixed population

Question 28: Aseptic conditions

Answer:

absence of pathogens