Deck 14: Benthic Communities

Question 1

Which of these statements is FALSE concerning estuaries?

A) Larvae are often abundant there.
B) Estuaries are in danger of development and pollution.
C) Very few autotrophs live in estuaries, but many animals can be found there.
D) Estuaries are places where saltwater and fresh water meet.

Answer 1

C

Question 2

Which of the following is FALSE concerning deep-sea floor organisms?

A) Several organisms have adapted unique feeding strategies.
B) Organisms that produce calcium carbonate skeletons are unusually strong.
C) Metabolic rates are typically low relative to an organism's surface-dwelling relative.
D) Most are small in size, but it is not unusual for species to demonstrate gigantism.

Answer 2

B

Question 3

Animals that are attached to the bottom are called:

A) sessile.
B) motile.
C) infaunal.
D) interstitial.

Answer 3

A

Question 4

The most common pattern for benthic organism distributions is:

A) clumped distribution.
B) negative binomial distribution.
C) random distribution.
D) uniform distribution.

Question 5

Perhaps the most difficult oceanic environments for small organisms to inhabit are:

A) low-energy abyssal plains.
B) high-energy sand and cobble beaches.
C) low-productivity salt marshes.
D) high-productivity rocky intertidal communities.

Question 6

According to Darwin, the last stage in the cycle of reef formation is:

A) the fringing reef.
B) the atoll.
C) the algal rim.
D) the barrier reef.

Question 7

Ahermatypic corals are:

A) found in shallow waters in the tropics.
B) have symbiotic algae.
C) are found in the deep-sea.
D) are actually plants.

Question 8

Tropical coral reefs require all of the following conditions to thrive EXCEPT:

A) clear, shallow water, preferably less than 10 meters ( 33 feet).
B) cold nutrient-rich water.
C) average salinity or slightly higher.
D) symbiotic dinoflagellates that reside inside the animal.

Question 9

In Darwin's description of reef structures, a fringing reef:

A) usually forms on the lee side of a tropical island.
B) has a deep lagoon that separates the reef from the island.
C) is ring-shaped and is not associated with an island.
D) is formed as a volcanic island sinks.

Question 10

Food in the intertidal zone is:

A) not particularly abundant, so resident organisms are in constant competition for the limiting resource.
B) abundant but inaccessible, so few organisms are able to inhabit the area.
C) abundant and accessible, but there are few organisms adapted to feed in this environment.
D) abundant and accessible, and there are many organisms that are adapted to take advantage of it.

Question 11

Intertidal organisms can protect themselves from wave shock by:

A) moving out to the open ocean during high tides.
B) adhering themselves to the rocks.
C) sliding out of small crack as the wave crashes around them.
D) releasing themselves from rocks..

Question 12

A reason for the great diversity and success of organisms in the rocky intertidal is:

A) the large quantity of food available.
B) the vast amount of space available.
C) the lack of nekton.
D) the rise and fall of the tides.

Question 13

Which of the following statements is FALSE concerning hydrothermal vents?

A) They are found in shallow waters near subduction zones.
B) Certain animals are found at hydrothermal vents such as pogonophorans .
C) Hydrothermal vents are found associated with spreading centers.
D) Vent waters cool as they are released from the vent.

Question 14

Which of these benthic habitats is NOT characterized by both high productivity and high biodiversity?

A) The hydrothermal vents in the deep sea.
B) Salt marshes associated with estuaries.
C) Rocky intertidal communities of the US west coast.
D) Sandy beaches of tropical shores.

Question 15

In the nutrient-poor water of the tropics, specialized dinoflagellates aid coral's success by:

A) providing carbon dioxide and phosphates for coral.
B) providing a safe and stable environment for coral.
C) causing coral bleaching.
D) providing oxygen, carbohydrates, and absorbing waste products.

Question 16

All of the following represent benthic communities EXCEPT:

A) phytoplankton.
B) kelp forest.
C) coral reef.
D) hydrothermal vent communities.

Question 17

Coral reef communities:

A) are made up exclusively of various species of coral polyps.
B) are made up of filter and suspension feeders living off the abundant plankton.
C) are limited to carnivorous animals.
D) are successful because they efficiently recycle nutrients

Question 18

Benthic organisms live:

A) on or associated with the seafloor.
B) suspended in the water column.
C) by drifting through the water, unable to swim against currents.
D) as parasites.

Question 19

The symbiotic dinoflagellate that lives within coral tissue is called:

A) kelp.
B) Riftia.
C) zooxanthellae.
D) polyp.

Question 20

Life in productive tropical reefs is characterized by:

A) extreme competition for food, territory, and reproductive opportunities.
B) very few species, but large numbers of each species.
C) large adults in each species that reproduce late in life.
D) organisms with extremely long lifespans.

Question 21

Hydrothermal vents that support biological communities exist because of primary productivity in the form of chemosynthesis.

Question 22

One might expect to encounter all of the following organisms in an estuary EXCEPT:

A) sea grasses
B) hermatypic corals
C) phytoplankton
D) juvenile fish

Question 23

One of Earth's most rigorous habitats is a:

A) sand beach.
B) coral reef.
C) kelp forest.
D) rocky intertidal.

Question 24

Interstitial animals are very small and live between sand grains.

Question 25

Species diversity is generally higher on the seafloor than in that part of the water column immediately above it.

Question 26

Kelp forests are most common in tropical latitudes.

Question 27

Physical conditions that contribute to the transparent waters of the tropics are:

A) low salinity and warm water.
B) no thermocline and abundant nutrients.
C) permanent thermocline and abundant nutrients.
D) an abrupt deep thermocline and lack of nutrients.

Question 28

Deep sea vent communities depend on specialized photoautotrophs that extract the exceedingly dim light that filters down to that depth.

Question 29

Organisms common in the rocky intertidal include all of the following EXCEPT:

A) benthic multicellular algae.
B) snails.
C) flat fish.
D) small sculpins.

Question 30

Algae are classified by:

A) their method of photosynthesis.
B) their location in the intertidal.
C) their photosynthetic pigments.
D) their size and shape.

Question 31

Seaweeds are:

A) vascular plants.
B) unicellular algae.
C) muticellular algae.
D) zooxanthellae.

Question 32

A physical challenge that high-intertidal organisms must adapt to is:

A) chemosynthesis.
B) zonation.
C) osmotic pressure.
D) desiccation.

Question 33

Hermatypic corals are corals that build reefs in tropical areas.

Question 34

Desiccation refers to the constant inundation of sub-tidal rocky reefs.

Question 35

An example of a vascular plant that is successful in low, muddy coasts in tropical and subtropical areas are:

A) mangroves.
B) ahermatypic corals.
C) kelp.
D) macroalgae.

Question 36

Estuaries are nutrient rich environments that foster very high biodiversity.

Question 37

Primary productivity in estuaries is high because:

A) light is seasonal and dim.
B) nutrients are abundant.
C) symbiotic autotrophs live within the tissues of estuary animals.
D) nutrients are abundant and light is dim.

Question 38

Marine algae are nonvascular plants.

Question 39

Which of the following groups of organisms includes only true marine vascular plants?

A) rhodophytes, chlorophytes and phaeophytes.
B) diatoms, dinoflagellates and coccolithophores.
C) kelp forests and seagrasses.
D) mangroves and salt marshes.

Question 40

The biomass of benthic algae in the ocean is greater than the biomass of phytoplankton.

Question 41

Is the distribution of benthic organisms random? Explain why or why not.

Question 42

Despite residing in the deep, dark sea, hydrothermal vents are able to support a diverse community of organisms including pogonophorans, clams, crabs, worms and many more species. Since no light reaches hydrothermal vents, explain what provides the basis of primary production and how it supports the community?

Question 43

Are the physical and chemical conditions stable in intertidal environments? Explain why or why not and provide examples to support your claims.

Question 44

Compare and contrast the stability of habitats found in the deep-sea.

Question 45

What is an atoll? Describe the steps that occur in the formation of an atoll.