Deck 12: The Plankton, Energy, and Food Webs

Question 1

The total productivity of upwelling areas is greater than the total productivity of open-ocean areas.

Answer 1

False

Question 2

If both primary productivity and grazing are large, the standing stock can not be small.

Answer 2

False

Question 3

If the rate of uptake of dissolved inorganic carbon by phytoplankton is measured, the rate of production of organic matter can be calculated.

Answer 3

True

Question 4

The total primary production of the world's oceans is determined more by the large seaweeds than it is by the single-celled microscopic phytoplankton.

Question 5

In grams of carbon per square meter per day, the open ocean environment is as productive as a tropical rainforest.

Question 6

Primary productivity per square meter of ocean surface is, on the average, higher in the neritic zone than in the oceanic zone.

Question 7

Approximately 15% of the world's ocean area produces 85% of the ocean's harvest.

Question 8

The shorter food chains of coastal and upwelling areas generally are more efficient than longer open-ocean food chains.

Question 9

The only zone of the ocean with sufficient light for photosynthesis is the

A) euphotic zone.
B) aphotic zone.
C) disphotic zone.
D) None of these choices.
E) All of these choices.

Question 10

The plankton, benthos, and nekton are subdivisions of the

A) seafloor.
B) littoral.
C) oceanic water column.
D) organisms.
E) continental shelf.

Question 11

At low latitudes, primary production is controlled more by the seasonality of the sunlight than by the availability of nutrients.

Question 12

Greater mixing and nutrients from the land cause the coastal areas to generally have higher primary productivity than the open ocean.

Question 13

Organisms that float, but cannot swim against the tides and waves, are known as

A) photon.
B) aphoton.
C) plankton.
D) nekton.
E) benthos.

Question 14

Gross primary production is the rate of production of organic material by photosynthesis required for both the respiration of the plants or algae and the production of new material.

Question 15

The upper boundary of the aphotic zone is determined by the depth of solar light penetration.

Question 16

The standing stock of a population is equivalent to its biomass.

Question 17

In temperate regions, both winter mixing and summer's increasing solar radiation control primary production.

Question 18

Net primary production equals gross primary production minus the respiration requirements of plants or phytoplankton.

Question 19

Nutrients tend to be liberated by decomposition of organic matter at depth and returned to the surface by the physical processes of vertical circulation.

Question 20

Productivity tends to be higher in the open ocean than the coastal ocean.

Question 21

Primary productivity is best described as

A) population.
B) standing crop.
C) life expectancy.
D) rate of birth minus rate of death.
E) rate of production of organic carbon.

Question 22

Chlorophyll a absorbs energy mostly in the blue and red wavelengths.

Question 23

Although light, nitrogen and phosphorous are abundant in the Pacific and Southern Oceans the plankton are less abundant due to

A) low surface temperature.
B) low oxygen levels at the surface.
C) lack of iron in surface waters.
D) low surface temperature and lack of iron in surface waters.
E) low surface temperature, low oxygen levels at the surface and lack of iron in surface waters.

Question 24

Phytoplankton biomass can be measured by satellite.

Question 25

In terms of grams of carbon per square meter per day, the open-ocean environment is about as productive as

A) prairie land.
B) alpine forests.
C) deserts.
D) intensively farmed fields.
E) tropical rain forests.

Question 26

Primary productivity is measured in terms of gC/m²/day.

Question 27

Approximately the same amount of primary productivity occurs in the oceans as occurs on land.

Question 28

Productivity in tropical oceans is limited by nutrient availability.

Question 29

At temperate latitudes, a stable water column with a pycnocline near the surface will _______ primary production in the spring and ________ primary production in late summer.

A) decrease; increase
B) increase; increase
C) increase; decrease
D) decrease; decrease
E) None of these are correct; both will be moderately productive.

Question 30

A high-oxygen content and a low-nutrient content in surface seawater indicate that a population of ______ are present.

A) animals
B) phytoplankton
C) bacteria
D) decomposers
E) None of these are correct; they indicate no life presence.

Question 31

The arctic region has low annual productivity because

A) the nutrient supply is low.
B) the water is cold.
C) ice covers the water in winter.
D) the intensity of solar radiation is low.
E) the oxygen level of the surface waters is low.

Question 32

When new marine phytoplankton biomass is produced by photosynthesis, dissolved carbon dioxide is converted to

A) carbon dioxide gas.
B) carbon dioxide solids.
C) soluble inorganic compounds.
D) organic carbon compounds.
E) None of these are correct.

Question 33

Satellites can detect ocean color.

Question 34

Upwelling areas are more productive than oceanic areas because _______ in upwellings.

A) organic matter is more concentrated
B) food chains are shorter
C) there are more nutrients
D) All of these are correct.
E) None of these are correct.

Question 35

Which of the following is not necessary for photosynthesis?

A) Light
B) Chlorophyll
C) Oxygen
D) Water
E) Carbon dioxide

Question 36

Productivity is higher at a surface convergence than surface divergence.

Question 37

Areas of divergence promote higher rates of primary production.

Question 38

When primary productivity is high, standing crop remains high and nearly constant.

Question 39

The most numerous and greatest biomass of herbivores are

A) zooplankton.
B) fish.
C) the great whales.
D) primary consumers.
E) zooplankton and primary consumers.

Question 40

A standing crop of phytoplankton can be measured by

A) determining the chlorophyll a content of a sample.
B) weighing the cells in a sample.
C) counting the cells in a sample.
D) All of these are correct.
E) None of these are correct.

Question 41

At higher and higher trophic levels, there are usually _____ and _______ animals.

A) fewer; smaller
B) fewer; larger
C) more; smaller
D) more; larger
E) None of these are correct; there is no change in number or size.

Question 42

The coccoliths on the outside of coccolithophores are made of silica.

Question 43

In a simple food chain with 10% efficiency, a net primary production rate at the first trophic level is 10,000 units. How many units are available to the fourth trophic level?

A) 1000
B) 100
C) 10
D) 1
E) 0.1

Question 44

An increase in the chlorophyll a content of a seawater sample with time yields a measurement of

A) change in the species of phytoplankton in the sample.
B) gross production of organic carbon.
C) plant respiration.
D) net production of organic carbon.
E) decomposition of plant cells.

Question 45

Adding iron to the surface of the ocean has been shown to

A) have no impact on phytoplankton community composition.
B) increase phytoplankton production for an initial short period.
C) make no difference to phytoplankton production.
D) be toxic to phytoplankton production.
E) All of these are false; this experiment has never been tried.

Question 46

As a general rule, total biomass _______, size of individuals _____, and number of individuals ______ as you move up a trophic pyramid.

A) increases; decreases; decreases
B) decreases; increases; decreases
C) increases; decreases; increases
D) decreases; decreases; increases
E) increases; increases; increases

Question 47

Sargassum is the only large planktonic seaweed.

Question 48

If baleen whales eat krill that eat diatoms, krill represents the _______ trophic level.

A) first
B) second
C) third
D) fourth
E) fifth

Question 49

Krill is the common name for copepods.

Question 50

Net plankton are larger than nannoplankton.

Question 51

The most common nutrient that limits coastal productivity is

A) oxygen.
B) phosphate.
C) nitrate.
D) carbon.
E) iron.

Question 52

If the net primary production in a region is continually consumed by herbivores, the standing stock

A) increases.
B) decreases.
C) does not change.
D) increases, decreases, or does not change depending on the time of year.
E) increases, decreases, or does not change depending on the nutrients present.

Question 53

There is less biomass per unit volume available for harvesting in the open ocean, as compared to upwelling and coastal zones, because

A) there are less nutrients.
B) there is less oxygen.
C) the salinity is greater.
D) the temperature is lower.
E) All of these are correct.

Question 54

The highest rates of productivity in temperate waters occur in

A) spring.
B) winter.
C) summer.
D) fall.
E) Productivity is the same during all seasons.

Question 55

Which compound does not serve as a pigment in phytoplankton?

A) Chlorophyll c
B) Chlorophyll a
C) Fucoxanthin
D) Hemoglobin
E) Phycoerythrin

Question 56

A food web is

A) a net for trapping marine organisms.
B) a plan of interactive food chains and energy.
C) an inverse trophic pyramid.
D) used only with herring life histories.
E) a diagram of an organisms's life history.

Question 57

The period of highest productivity in polar areas is

A) summer.
B) winter.
C) spring
D) fall.
E) Productivity is similar in all seasons.

Question 58

The Redfield Ratio is

A) N:C:P 106:16:1.
B) P:C:N 106:16:1.
C) C:P:N 106:16:1.
D) C:N:P 106:16:1.
E) P:N:C 106:16:1.

Question 59

In temperate waters, the timing of the phytoplankton bloom is influenced by

A) light intensity.
B) inorganic nutrient concentrations.
C) stability of the water column.
D) zooplankton abundance.
E) All of these are correct.

Question 60

The biomass of planktonic, unicellular algae in tropical regions

A) remains nearly constant over the year.
B) increases during the summer months.
C) decreases during the summer months.
D) increases during the winter months.
E) decreases during the winter months.

Question 61

Which organisms are members of the holoplankton?

A) Foraminaferans
B) Pteropods
C) Comb jellies
D) All of these are correct.
E) None of these are correct.

Question 62

Autotrophic organisms are

A) able to chemosynthesize.
B) the base of the food web.
C) able to photosynthesize.
D) All of these are correct.
E) None of these are correct.

Question 63

Some ctenophores are herbivores while others are carnivores.

Question 64

Viral abundance is strongly correlated with plankton biomass.

Question 65

The most abundant phytoplankton in the open ocean is the cyanobacterium Prochlorococcus.

Question 66

Dinoflagellates are known for

A) producing toxins that can be lethal to humans.
B) their ability to glow with bioluminescence.
C) their formation of bottom sediments.
D) producing toxins that can be lethal to humans and their ability to glow with bioluminescence.
E) producing toxins that can be lethal to humans, their ability to glow with bioluminescence, and their formation of bottom sediments.

Question 67

Dinoflagellates and coccolithophores belong to the

A) phytoplankton.
B) zooplankton.
C) benthos.
D) nekton.
E) decomposers.

Question 68

Holoplankton spend only their larval stages in the plankton.

Question 69

Archaea are found only in physically extreme environments such as hydrothermal vents.

Question 70

Some phytoplankton species migrate as much as 500m vertically every day.

Question 71

DOM or Dissolved Organic Matter is largely unused by other organisms.

Question 72

Diatoms are able to

A) form chains to help floating.
B) store oil to reduce their density.
C) produce two flagella that provide motility and reduce sinking.
D) form chains to help floating and store oil to reduce their density.
E) form chains to help floating, store oil to reduce their density, and produce two flagella that provide motility and reduce sinking.

Question 73

Populations of zooplankton can

A) accumulate at water-layer density boundaries.
B) move toward the sea surface at night.
C) reflect sound waves.
D) accumulate at water-layer density boundaries and reflect sound waves.
E) accumulate at water-layer density boundaries, move toward the sea surface at night, and reflect sound waves.

Question 74

Comb jelly is another name for jellyfish.

Question 75

All phytoplankton are capable of photosynthesis.

Question 76

All harmful algal blooms are caused by dinoflagellates.

Question 77

Red tides may or may not be poisonous to other marine organisms.

Question 78

The dominant phytoplankton in the open ocean are members of the picoplankton.

Question 79

Cyanobacteria are one of only a few organisms able to use nitrogen gas to make organic matter.

Question 80

Which is not a member of the zooplankton?

A) A copepod
B) An arrowworm
C) A fish egg
D) A diatom
E) A jellyfish