T OR F Flashcards
Iron is thought to be the primary nutrient limiting the growth of heterotrophic bacteria in the sea
FALSE. DOC is generally thought to be limiting.
At any given time, about 20% of marine bacteria may be infected by viruses.
TRUE
The turnover time for a nutrient in seawater decreases as the concentration increases.
FALSE. Turnover time increases.
The ‘microbial loop’ is considered a major pathway of carbon transport to crustacean zooplankton.
False. Most C is burned up in respiration.
Food chains tend to be longer in more oligotrophic environments.
False:tend to be shorter
UV-B radiation is used to refer to wavelength between 320 nm and 380 nm
FALSE. 290-330 nm.
Dissolved free amino acid concentrations in seawater are typically in nM range.
TRUE.
Changes in viral abundance are correlated to changes in bacterial abundance.
TRUE.
The process of conversion of ammonium to nitrate is nitrification.
TRUE
Viruses infecting cyanobacteria belong to a group of viruses called the Cytophagales.
FALSE. cytophagales are bacteria. Viruses infecting cyanobacteria are called cyanophages.
In coastal water that maximum wavelength of light penetration is shifted to longer wavelengths.
TRUE.
Heterotrophic bacteria assimilation efficiences of carbon are highest when C:N of substrates are also highest.
False. C assimilations efficiencies are lower when C:N ratio is high.
Oceanic gyres south of the equator rotate counterclockwise
True
The phytoplankton C:chl ratio should be higher at the subsurface chl maximum than at the surface.
False: lower light means more Chl is produced, so C:Chl should be lower.
Relative to phytoplankton, the ratio of N to C is greater in heterotrophic bacteria.
True.
Grazing rates of ciliates are typically higher than grazing rates of heterotrophic flagellates.
True
The viral shunt describes the process of respiration that is caused by the lysis of bacteria by viruses
False. The viral shunt is the process whereby cellular C and other nutrients are released by viral lysis and make available for incorporation by other cellular organisms.
A chl concentration of 5mg/L is reasonable for the Strait of Georgia.
no. 5 ug.
Net primary production and bacterial production are typically about equal in the open ocean.
False, primary production exceeds bacterial production.
A reasonable estimate of C in a Synechococcus cell is 250 fg.
True
All wavelengths of light are attenuated more quickly in coastal waters than in clear, oligotrophic water
True
16s rDNA amplicon sequencing is a good way to examine function potential in a bacterial community
False, it give taxonomic profiling, which is not a good indicator of function.
The RNA-dependent RNA polymerase is a MARKER GENE that is used to look at the diversity of RNA viruses.
True
Protist grazing is largely a carbon and energy sink, rather than a link in the marine food web.
True
Cold core rings in the NH rotate in a clockwise direction
False: rotate CCW.
The microbial carbon pump, “pumps” DOC from surface to the deeper water.
False the MCP is a proposed mechanism that concentrated DOC in the water by using the labile DOC and leaving behind the recalcitrant DOC.
A lysogenic life style is favoured under oligotrophic conditions.
True
Free ribosomes exist in seawater.
True
Picornavirales are a group of RNA viruses
True
On balance, bacterial production is considered to be more important as a link than a sink for carbon transfer in marine foodwebs.
False, considered more of a sink.
Bacterial Gross Growth efficiency increases as the C:N ratio of the substrate increases.
False, it decreases.
Clearance rates for ciliates are usually much greater than those of flagellates.
True.
Oceanic food chains are typically shorter than coastal ones.
True
The geographic distribution of viruses infecting the genera Synechococcus and Prochlorococcus are similar.
False, viruses infecting proc. are generally not detectable in temperate water.
Phycoerythrin should be the dominant pigment in Syn found in the Strait of Georgia.
False, should be phycocyanin.
There would be a seasonal deep-chlorophyll maximum in the tropical waters of the South Pacific
False, the DCM would be permanent
The proportion of C respired is greater for high C:N ratio substrates than low C:N ratio substrates.
True.
Assuming everything else is the same, the C:Chlorophyll ratio of phytoplankton will be greater under low light that under high light.
False, more chl is produced under low light, so the ratio will be lower.
