EEB 4611 Exam II Review - Quiz Questions

Water has a dipole moment which leads to what other property of water?

a. High specific heat

b. High heat of fusion

c. All of these

d. Surface tension

c. All of these

Which property of water leads to ice floating?

a. Liquid water achieves its greatest density at about 4 degrees C

b. Solid water (ice) is much less dense than liquid water

c. Solid water (ice) is denser than liquid water

d. Sea water achieves its greatest density at about 0 degrees C

b. Solid water (ice) is much less dense than liquid water

The predominant form of DIC (dissolved inorganic carbon) in most MN freshwaters is:

a. CO2

b. bicarbonate

c. carbonate

d. carbonic acid

b. Bicarbonate

True or false: a 2 µm particle sinks in lakes faster than a 10 µm particle.

False

True or false: most algae are negatively buoyant

True

True or false: carbonate precipitation should occur more prevalently in lakes in the Arrowhead than in south-west Minnesota.

False

True or false: more organic carbon is buried in freshwater ecosystems than in all of the ocean.

True

How many Pg of carbon (mostly as CO2) are released by freshwaters to the atmosphere annually?

a. 2-4

b. 0.2-0.3

c. 30-50

d. 20-30

a. 2-4

Why are the C:P ratios of particles in freshwaters higher and more variable than those in the ocean?

a. There is greater influence of terrestrial organic matter and residence times are less variable.

b. There is less influence of terrestrial organic matter and residence times are more variable.

c. There is less influence of terrestrial organic matter and residence times are less variable.

d. There is greater influence of terrestrial organic matter and residence times are more variable.

d. There is greater influence of terrestrial organic matter and residence times are more variable.

Schindler's experiments at the Experimental Lake Area in Canada demonstrated that: 

a. Lakes are limited by N

b. Lakes are limited by light

c. Lakes are limited by P

d. Lakes are limited by C

c. Lakes are limited by P

Which ion is most abundant in the ocean?

a. Cl

b. Na

c. K

d. HCO3

a. Cl

The oceans have layers of different density due to: 

a. Temperature differences

b. Pressure differences

c. Salinity differences

d. Temperature and salinity differences

d. Temperature and salinity differences

True or false: hydrothermal vents are a source of salt to the oceans.

True

Ocean deep water formation occurs where?

a. At low latitudes

b. At mid-latitudes

c. At high latitudes

d. All of the above

c. At high latitudes

Upwelling in the ocean occurs primarily where?

a. On the western side of continents

b. On the eastern side of continents

c. In the central gyres

d. Along the equator

a. On the western side of continents

Calcite is more soluble in the deep ocean than the shallow ocean due to: 

a. It is colder

b. pH is lower

c. Lower pH and colder temperatures

d. It is the same in the surface and deep ocean

c. Lower pH and colder temperatures

When CO2 dissolves in water what happens to the pH?

a. It goes down

b. It goes up

c. It stays the same

d. The carbonate concentration goes up

a. It goes down

What process is most responsible for the removal of 2 Pg C from the atmosphere to the oceans?

a. Solubility pump

b. Biological pump

c. DOC pump

d. Subduction of ocean sediments

a. Solubility pump

The pH of the Pacific Ocean deep water is lower than the pH of the Atlantic Ocean because:

a. The pacific deep water is younger than the Atlantic

b. The pacific deep water is older than the Atlantic

c. There is more ocean acidification in the Pacific

d. It is deeper than the Atlantic

b. The pacific deep water is older than the Atlantic

Ocean acidification makes it more difficult for corals to grow because:

a. Calcite saturation increases

b. Calcite saturation decreases

c. Carbonic acid concentration increases

d. Carbonic acid concentration increases

b. Calcite saturation decreases

Which factor is most likely to limit primary production at 100 m depth?

a. Light

b. Nitrogen

c. Phosphorus

d. Iron

a. Light

Which factor is most likely to limit primary production in the Southern Ocean?

a. Light

b. N

c. P

d. Fe

d. Fe

The Redfield ratio is:

a. 106P: 16N: 1C

b. 106C: 50N: 1P

c. 106C: 16N: 1P

d. 250C: 20N: 1P

c. 106C: 16N: 1P

Ocean acidification has what effect on the calcite compensation depth?

a. It increases it

b. It decreases it

c. It has no effect

b. It decreases it

True or false: ocean primary production is greater than terrestrial primary production.

False

Export production refers to:

a. The ratio of organic matter exported from the mixed layer relative to net primary production

b. The ratio of organic matter in biomass relative to that dissolved in water

c. The ratio of carbon to phosphorus

d. The ratio of nitrogen to phosphorus

a. The ratio of organic matter exported from the mixed layer relative to net primary production

Liebig argued that how many factors limit the production of primary producers?

a. One

b. Two

c. Three

d. An infinite amount

a. One

True or false: most production in the ocean is ‘new’ production

False

Atmospheric deposition is an important source of which nutrient to the surface ocean?

a. Fe

b. N

c. P

d. Si

b. N

True or false: nitrogen fixation can compensate for a lack of N in ecosystems.

True

Liebig's 'Law of the Minimum' assumes:

a. Only one nutrient is limiting at a time

b. Two nutrients can be limiting simultaneously

c. Multiple nutrients can be limiting simultaneously

d. All of these

a. Only one nutrient is limiting at a time

The Redfield ratio for N:P is...?

a. 106:1

b. 16:1

c. 6.6:1

d. Dumb and irrelevant

b. 16:1

Which factor is likely to be most limiting to primary producers (algae) at 20m depth in the North Atlantic gyre?

a. Nitrogen

b. Phosphorus

c. pH

d. Iron

d. Iron

True or false: fe limitation is common in the high nutrient-low chlorophyll regions of the ocean.

True

You are on a cruise in the central Pacific Ocean and grab a water sample from 20m-depth. You take it back to your lab and measure C, N and P of the particles (mostly phytoplankton). You calculate the biomass ratio for this sample as 110C: 30N: 1P and conclude that these algae were most likely __________ -limited.

Phosphorus

Which of the following statements is true?

a. Denitrification works best when it is coupled to nitrification

b. Nitrification works best when it is coupled to anammox

c. Denitrification works best when it is coupled to ammonification

d. Nitrification works best when it is coupled to sulfate reduction

a. Denitrification works best when it is coupled to nitrification

Which of the following should degrade fastest?

a. Leaves with a C:N ratio of 10

b. Leaves with a C:N ratio of 20

c. Leaves with a C:N ratio of 300

d. Leaves with a C:P ratio of 500

a. Leaves with a C:N ratio of 10

Which statement is true about denitrification?

a. Phosphate is a required substrate

b. Denitrification is coupled to nitrification

c. Ammonium is a required substrate

d. N2 is a required substrate

b. Denitrification is coupled to nitrification

Nitrogen is fixed to ammonium via the Haber process to produce fertilizer. What is the source of N?

a. Nitrate in water

b. N2 in air

c. Nitrate in air

d. N2 in water

b. N2 in air

The substrates for anammox are: 

a. Nitrate and ammonium

b. Nitrite and ammonium

c. Organic carbon and nitrite

d. Nitrite and nitrate

b. Nitrite and ammonium

Which of these elements has the most stable redox states in natural systems?

a. N

b. P

c. C

d. O

a. N

Which element does not have a significant atmospheric component?

a. C

b. P

c. S

d. N

b. P

Which compound is the least soluble in the ocean?

a. Ammonium

b. Bicarbonate

c. Phosphate

d. Nitrate

c. Phosphate

Which of the following is where humans use the most P?

a. Insecticides

b. Herbicides

c. Toothpaste

d. Fertilizer

d. Fertilizer

P limitation in terrestrial ecosystems is most likely to occur where?

a. Old arctic soils

b. Young tropical soils

c. Old tropical soils

d. Young arctic soils

c. Old tropical soils

Which does not add fixed N to ecosystems?

a. The Haber process

c. Cultivation of legumes

c. Automobile internal combustion engines

d. Denitrification

d. Denitrification

True or false: the country with the most reserves of mineable P rock is China.

False

Which element has been most perturbed by humans relative to natural processes?

a. O

b. N

c. C

d. P

d. P

True or false: nitrogen is more volatile than is phosphorus.

True

True or false: phosphorus is more soluble than nitrogen.

False

Where is most sulfur found in organisms?

a. Protein

b. DNA

c. Lipids

d. Cytosol

a. Protein

Sulfide oxidizers are which type of metabolism?

a. Chemolithoautotrophs

b. Photolithotrophs

c. Chemolithoautotrophs or photolithoautotrophs

d. Heteroganotrophs

c. Chemolithoautotrophs or photolithoautotrophs

Which process is critical to pyrite formation?

a. Sulfate reduction

b. Sulfide oxidation

c. Photoferrotrophy

d. All of the above

a. Sulfate reduction

How does ∂³⁴S change in marine sediments as sulfate concentrations increase?

a. It stays the same

b. It decreases

c. It increases

d. None of the above

c. It increases

What factors contributed to decreased acid deposition in the eastern US from the 1980s to the present?

a. Sulfur scrubber installation in power plants

b. The Clean Air Act

c. Cap and trade

d. All of the above

d. All of the above

True or false: in the CLAW hypothesis, the warming of the oceans leads to increased consumption of DMS by phytoplankton and decreased cloud formation. 

False

Mt Ruang, a volcano in Indonesia erupted yesterday and is believed to have injected gases as high as 70,000 feet. If so, how will this affect our climate for the next several years?

a. It will warm the Earth

b. It will cool the Earth

c. It will have no effect

b. It will cool the Earth

How much have humans influenced the global sulfur cycle?

a. We have doubled it

b. We have tripled it

c. We have quadrupled it

d. We have had little to no effect

a. We have doubled it

In the Archaean Ocean, the concentration of sulfate would have been ________ than the concentration in the ocean today.

a. Slightly lower

b. Slightly higher

c. Much lower

d. Much higher

c. Much lower

Which compound has the greatest influence on sulfate concentrations in the oceans today?

a. H₂CO₃

b. H₂SO₄

c. CaSO₄

d. FeS₂

c. CaSO₄