Question 1

The use of modern molecular techniques has provided a mechanism for growing the microorganisms previously referred to as unculturable.

Accepted Answer

False

Question 2

Optical tweezers can be used to

Accepted Answer

A

Question 3

When doing SSU (small subunit ribosomal RNA)of a mixed population of microbes from an environmental sample,specific _____________ are identified.

Accepted Answer

SSU rRNA sequencing is a molecular method used to identify microbial communities in environmental samples based on the presence of specific sequences (phylotypes) that correspond to known microbial groups. It does not identify individual phenotypes or genotypes and does not necessarily detect all unknown microbes in the sample.

Question 4

The level of specific mRNA,and therefore the expression of a given gene in a particular ecosystem,can be evaluated in the environment using in situ reverse transcriptase (ISRT)-FISH.

Accepted Answer

In situ reverse transcriptase (ISRT)-FISH can be used to evaluate the level of specific mRNA and gene expression in the environment.

Question 5

Phylogenetic oligonucleotide arrays (POAs)contain rRNA sequences as probes and are used as a means to detect complementary rRNA sequences from the environment.

Accepted Answer

Phylogenetic oligonucleotide arrays (POAs) do contain rRNA sequences as probes and are used for detecting complementary rRNA sequences from the environment.

Question 6

Which of the following is microscopy in which the microscope is fitted with light filters that enable the excitation of the specimen with a specific wavelength?

Accepted Answer

Epifluorescence microscopy is the only option given that mentions the use of light filters to specifically excite the specimen with a certain wavelength. Electron microscopy uses electron beams, while bright-field and dark-field microscopy do not typically involve the use of filters to excite the specimen.

Question 7

_______ culture are pure cultures,consisting of a single species.

Accepted Answer

The answer of _______ culture are pure cultures,consisting of a...

Question 8

A technique used to quantify specific types of microbes in natural samples,enrichment cultures,and food or water samples is known as the _______ ________ _______ technique.

Accepted Answer

The answer of A technique used to quantify specific types...

Question 9

The fact that cells of genetically uniform population do not have similar phenotypic attributes is called ____________ heterogeneity.

Accepted Answer

The answer of The fact that cells of genetically uniform...

Question 10

It is generally agreed that SSU (small subunit ribosomal RNA)analysis is a technique that is well suited to identifying species present in a given community.

Accepted Answer

SSU analysis is commonly used for taxonomic identification of organisms in a community due to its high resolution and ability to distinguish between closely related species.

Question 11

The discrepancy between the number of microbial cells observed by microscopic examination and the number of colonies that can be cultivated from the same natural sample may be due to

Accepted Answer

The discrepancy between the number of microbial cells observed by microscopic examination and the number of colonies that can be cultivated from the same natural sample may be due to nonviable organisms or incorrect culture conditions, or both. Nonviable organisms may be present in the microscopic examination but unable to grow on culture media. Incorrect culture conditions may result in a lack of growth or inhibition of certain microbes.

Question 12

When PCR amplification of SSU (small subunit ribosomal RNA)yields a population of different PCR products of about the same molecular weight,these fragments can be separated for further analysis by

Accepted Answer

Denaturing gradient gel electrophoresis (DGGE) is a commonly used technique for resolving PCR products that differ by sequence. DGGE takes advantage of differences in the melting behavior of DNA fragments. By subjecting a mixture of denatured DNA fragments to electrophoresis through a gel with a linear gradient of denaturant, fragments that differ by a single base pair can be distinguished based on differences in their melting behavior. In this case, SSU PCR products of about the same molecular weight can be separated and further analyzed by DGGE.

Question 13

When fluorescently labeled oligonucleotides that are known to be specific to the microbe of interest are used to label natural samples,the technique is known as

Accepted Answer

The technique of using fluorescently labeled oligonucleotides specific to the microbe of interest to label natural samples is known as fluorescent in situ hybridization (FISH). Polymerase chain reaction (PCR) is a technique used to amplify DNA, gel electrophoresis is used to separate molecules based on their size and charge, and epifluorescence microscopy is a type of microscopy that utilizes fluorescence to visualize samples. None of these techniques are specifically used for labeling microorganisms in natural samples.

Question 14

_______ _______ arrays are used to assess the diversity of a microbial population.

Accepted Answer

The answer of _______ _______ arrays are used to assess...

Question 15

What percentage of microbes have been cultured in the laboratory?

Accepted Answer

Only a small percentage of microbes, estimated to be around 1%, have been cultured in the laboratory. The majority of microbes remain uncultivated or are difficult to culture using traditional methods, leading to a vast amount of microbial diversity that remains unknown to science.

Question 16

Determining the functional nature of a microbial community by analysis of bulk DNA samples extracted from environmental samples may be misleading for all of the following reasons except:

Accepted Answer

While DNA can be helpful in identifying certain microbes, it is not always reliable for determining the functional nature of a microbial community. The other options provided (B, C, and D) are all valid potential reasons why bulk DNA analysis may be misleading.

Question 17

Recent evidence suggests that most microbial communities have many individuals representing at least ______ taxa.

Accepted Answer

The answer of Recent evidence suggests that most microbial communities...

Question 18

________ culture techniques are based on the expansion of the microenvironment to allow abundant growth of a microorganism formerly restricted to a small ecological niche.

Accepted Answer

The answer of ________ culture techniques are based on the...

Question 19

The fact that certain nucleotide templates are more readily amplified than others is termed

Accepted Answer

The term used to describe the fact that certain nucleotide templates are more readily amplified than others is PCR bias. Multiplex PCR refers to amplifying multiple targets simultaneously, analytical PCR is a generic term for any PCR-based technique used for analysis, and real-time PCR is a technique that allows for quantification of PCR products in real time.

Question 20

In the microdroplet culture method,cells from mixed assemblages are encapsulated in a gel matrix.The matrix is then emulsified to generate gel "microdroplets"; each microdroplet contains a mixture of cells.

Accepted Answer

In the microdroplet culture method, cells from mixed assemblages are encapsulated in droplets of a gel matrix, but the goal is typically to isolate single cells or clones within each microdroplet, rather than mixtures of cells. This allows for the study or cultivation of individual cells in isolation.

Quiz 29: Methods in Microbial Ecology