Question 1

The diversity of microorganisms in culture collections is representative of the diversity of microorganisms found in nature.

Accepted Answer

Culture collections generally contain a limited subset of microorganisms that have been able to be cultured under laboratory conditions, which may not reflect the true diversity found in nature where many microorganisms are unculturable.

Question 2

By using simple microscopy techniques,it is possible to determine if a culture is contaminated with another organism.

Accepted Answer

By observing the morphology and characteristics of the cells under a microscope, it is possible to identify if there are any foreign cells in the culture that may indicate contamination. For example, if a bacterial culture appears to have multiple types of cells with different shapes and sizes, it could indicate contamination by another microorganism.

Question 3

Several fluorogenic dyes can be used simultaneously in a sample as long as they each emit light at a different measurable wavelength.

Accepted Answer

This statement is true. Fluorogenic dyes can be used simultaneously in a sample as long as they each emit light at a different measurable wavelength. This allows for multiple targets to be detected and measured within the same sample.

Question 4

What prior knowledge is required to use a phylochip to study the abundance of the different microbes present within a microbial community? How does this cause bias when using a phylochip to analyze microbial community structure?

Accepted Answer

The answer of What prior knowledge is required to use...

Question 5

Using specific examples,when is it appropriate to use CARD-FISH rather than the traditional FISH method and vice-versa?

Accepted Answer

The answer of Using specific examples,when is it appropriate to...

Question 6

We know that that there are over 50 major phyla in Bacteria; however,only about 25 of these phyla have cultured representatives.Why is this? How are scientists attempting to culture representative from the 25 phyla that do not currently have any organisms in culture?

Accepted Answer

The answer of We know that that there are over...

Question 7

Combined with autofluoresence or fluorescent DNA probes,flow cytometry can separate or count populations of cells from aquatic environments.

Accepted Answer

Flow cytometry combined with autofluorescence or fluorescent DNA probes can be used to separate or count populations of cells from aquatic environments.

Question 8

In natural samples it is often difficult to differentiate live cells from dead cells or cells from nonliving matter.

Accepted Answer

This is because natural samples may contain debris, non-living organic matter, or other particles that can be similar in size and shape to cells, making it challenging to distinguish between live and dead cells or between cells and non-living matter. Various staining and imaging techniques can be used to distinguish live vs. dead cells in a sample.

Question 9

FISH technology can employ only a single phylogenetic probe.

Accepted Answer

FISH technology can employ multiple phylogenetic probes, allowing for the visualization and identification of different specific genetic targets within a sample.

Question 10

Phototrophic organisms in SIP experiments are often observed releasing ¹⁴CO₂ as measuring activity.

Accepted Answer

The answer of Phototrophic organisms in SIP experiments are often...

Question 11

What are the pros and cons of traditional enrichment culture techniques? What advances in the last decade are improving enrichment culture techniques to aid the cultivation of uncultured microorganisms?

Accepted Answer

The answer of What are the pros and cons of...

Question 12

Propose an experiment to identify members capable of assimilating monomers of lignin within a microbial community.

Accepted Answer

The answer of Propose an experiment to identify members capable...

Question 13

A study of the human gut performed in 1982 used various types of plates under different growth conditions to describe and enumerate the microbes in the human gut.They concluded that the majority of the microbes in the human gut are Gammaproteobacteria.A study conducted in 2010 using next-generation sequencing to characterize 16S rRNA sequences concluded that the majority of the microbes in the human gut are Firmicutes and Bacteriodetes.Why did these studies have different conclusions? Which study do you think is most accurate?

Accepted Answer

The answer of A study of the human gut performed...

Question 14

How can NanoSIMS be used to determine which Roseobacters most strongly use DMSP as a sulfur source within a coastal marine environment? Explain the NanoSIMS methodology in your answer.

Accepted Answer

The answer of How can NanoSIMS be used to determine...

Question 15

DGGE and T-RFLP are both molecular microbial ecology methods that use the polymerase chain reaction to amplify specific genes to assess diversity.

Accepted Answer

Both DGGE (Denaturing Gradient Gel Electrophoresis) and T-RFLP (Terminal Restriction Fragment Length Polymorphism) are PCR-based methods used in molecular microbial ecology to assess the diversity of specific genes within a microbial community. DGGE uses denaturing gradients to separate DNA fragments based on their melting behavior, while T-RFLP uses restriction enzymes to cleave DNA at specific sites and generate length polymorphisms. Both methods can be used to examine the diversity of bacterial or fungal communities in environmental samples.

Question 16

Describe what an ITS region is in the context of prokaryotes,and explain the significance of the ITS region for microbial ecology.

Accepted Answer

The answer of Describe what an ITS region is in...

Question 17

Describe how FISH can be used to determine which cells within a microbial community are actively degrading toluene.Assume the genes involved in the metabolic pathway have been sequenced from several microorganisms and vary only slightly from one another.

Accepted Answer

The answer of Describe how FISH can be used to...

Question 18

Metaproteomics is a more developed field than metatranscriptomics due to the high sensitivity of mass spectrometry.

Accepted Answer

Metaproteomics and metatranscriptomics are both rapidly developing fields, but the development of one over the other is not solely due to the sensitivity of mass spectrometry. Both fields face unique challenges and advancements, and their development is influenced by a variety of factors including technological advancements, computational methods, and application areas.

Question 19

The Winogradsky column is a method for assessing the entire gene complement of a habitat,revealing both the biodiversity and metabolic capabilities of the microbial community at the same time.

Accepted Answer

The Winogradsky column is a simple device for culturing a diverse community of microorganisms. It is used to study the metabolic activities of the microbes in different layers of sediment, not for assessing the entire gene complement of a habitat.

Question 20

The MPN technique is rarely applied in the food industry because any microbial presence in food is unsafe.

Accepted Answer

The MPN technique is actually commonly used in the food industry to estimate the number of microorganisms present in a sample. It is important for food safety and quality control measures.

Quiz 18: Methods in Microbial Ecology