Deck 10: The Open Sea: Distributions and Adaptations

Question 1

Which of the following explanations of diurnal vertical migrations cannot be excluded by available data?

A) Predation is stronger near the surface during daylight
B) The zooplankton are seeking a certain temperature, which varies between day and night
C) Strong light is harmful
D) Zooplankton are responding directly and only to diurnal changes in ambient light

Answer 1

A

Question 2

Diurnal vertical migrations are a feature of

A) All phytoplankton and zooplankton
B) All zooplankton
C) Nearly all zooplankton capable of swimming
D) All zooplankton, with the exception of copepods

Answer 2

C

Question 3

With regard to diurnal vertical migration, nearly transparent gelatinous forms

A) Pose problems for the energy hypothesis
B) Pose problems for the predation hypothesis
C) Can swim too slowly to account completely for their vertical ascent
D) All of the above

Answer 3

B

Question 4

Bioluminescence can be used for

A) Counter illumination
B) Lures
C) Deceptive signals
D) All of the above

Question 5

A phytoplankton patch can be maintained by

A) Reducing turbulence
B) Reducing current velocity
C) Increasing phytoplankton growth
D) All of the above

Question 6

Larger nekton are known to move great distances in the open sea because

A) Optimal temperature is constantly shifting, and nekton seek the optimal temperature
B) Large nekton must swim to breathe
C) Nekton movements are controlled only by movements to breeding areas
D) Nekton follow shifting centers of productivity

Question 7

Larger nekton have migration routes in the Pacific that are

A) Essentially identical
B) Controlled by a single trans-Pacific route at the equator
C) Divided between two major routes mainly
D) Confined to moving along the shelf-slope break of the eastern or western Pacific

Question 8

Most smaller organic particles in the ocean

A) Are denser than seawater and sink steadily but slowly
B) Are less dense than seawater and rise to the surface slick
C) Usually sink rapidly to the deep sea floor
D) Immediately decompose in the surface waters

Question 9

Gas secretion by some nekton is used

A) To allow an organism to rise rapidly to the surface
B) To allow an organism to adjust osmotic strength to adapt to changing salinity
C) To prevent rapid motion
D) To allow for neutral buoyancy

Question 10

Midwater fish

A) Often have bioluminescent organs on the ventral surface
B) Usually have light color on the dorsal surface
C) Can become completely invisible by spreading black cellular structures all over the body surface
D) Are usually very conspicuous and are very vulnerable to attacks from below

Question 11

Many anglerfish

A) Have brightly colored stalks to attract prey
B) Have a capsule filled with bioluminescent bacteria to attract prey
C) Have very reduced mouths to consume the very small prey they tend to attack
D) Are suspension feeders