General Microbiology: Chapter 19

B

Microarrays are useful for assessing A. enzyme activity. B. gene expression and the presence of specific rRNA sequences. C. gene expression only. D. the presence of specific rRNA sequences only.

B

Phylogenetic stains, such as those used in phylogenetic FISH, hybridize with A. nuclear DNA. B. ribosomal RNA. C. RNA polymerase. D. mitochondrial DNA.

C

In microbial ecology studies, the FISH technique identifies organisms based on A. fluorescence of unique cofactors or pigments under certain wavelengths of UV light. B. the presence of green fluorescent protein. C. hybridization of a fluorescent probe to specific ribosomal RNA sequences. D. the presence of luciferase.

True

True or False. One way to study a microbial ecosystem is to isolate microorganisms from it and study their properties in laboratory culture.

A

By isolating total community RNA, using reverse transcriptase to make cDNA copies of it, and then sequencing the cDNA, ecologists can __________. A. determine the community genome expression at the moment of sampling B. determine the community genomic potential at the moment of sampling C. determine the community genome translation at the moment of sampling D. determine the community metabolic activity at the moment of sampling

D

Fluorescent in situ hybridization (FISH) can be used to determine __________. A. how many Salmonella typhimurium cells are present in a sample of unpasteurized apple juice B. whether a specific piece of mRNA is being produced C. the phylogenetic diversity of an environmental sample D. all of the listed conditions

B

The phylogenetic diversity analysis of complex microbial communities often targets small subunit (SSU) ribosomal RNA genes. This is because rRNA is found in all organisms and __________. A. is easier to extract from samples B. is highly conserved over evolutionary time C. has more genes than mRNA D. is made by cells only at certain times

B

The term used when an organism is studied in its natural environment is A. au naturale. B. in situ. C. in vitro. D. in toto.

B

For microbial biodiversity studies, it is common to identify the ________ rather than the ________ as a measure of biodiversity. A. organisms themselves/genes B. genes/organisms themselves C. cell types/genes D. cell types/organisms themselves

C

How do viability stains usually distinguish between living cells and dead cells? A. The dye's fluorescence is quenched by dead cells. B. The chemical stain is taken up by living cells and once metabolized becomes fluorescent. C. The dye specifically targets intact cytoplasmic membranes. D. The chemical fluoresces only when bound to ribosomes that are actively synthesizing proteins.

B

Metagenomics involves the analysis of a microbial community by __________. A. sequencing all of the community RNA in an environment B. sampling and sequencing all of the genes in an environment C. generating a phylogenetic tree based on all of the versions of a gene in an environment D. generating a complete sequence of the genomes of all of the organisms in an environment

B

Metagenomics is a more sensitive analysis of community diversity than rRNA-based analyses because __________. A. rRNA genes are not found in all of the organisms present in the environment B. genes do not have to be amplified by PCR before being sequenced C. more clone libraries can be assembled D. the extraction of the DNA from the environmental samples is more efficient

B

Microarrays that have been designed to screen samples for specific groups of bacteria are called __________. A. biochips B. phylochips C. microchips D. phytochips

D

Which fluorescent molecule enables visualization of living microorganisms? A. SYBR® Green B. DAPI C. acridine orange D. GFP