Question 1

Besides reef-building corals,the most important organisms that help form coral reefs are:

Accepted Answer

Coralline algae are important organisms that help form coral reefs by depositing calcium carbonate, which contributes to the framework of the reef. They also provide a surface for coral larvae to settle on and grow.

Answer: E
 Forams (foraminifera) are tiny single-celled organisms that build calcium carbonate shells, which contribute to the formation of the reef structure. They also play an important role in providing a source of food for other reef organisms.

Question 2

Reef-building corals are classified as:

Accepted Answer

Reef-building corals are known as hermatypic corals. They have a symbiotic relationship with algae called zooxanthellae, which help them photosynthesize and provide most of their energy. Hermatypic corals are important because they build and maintain reef structures.

Question 3

Sources of food and other essential nutrients for corals include all of the following except:

Accepted Answer

Corals do not get essential nutrients from calcium carbonate from shells, although they do use it to build their skeletons. The other options are all sources of food and nutrients for corals. Zooplankton and dissolved organic matter can be captured using mesenterial filaments or captured by the tentacles. Nutrients released by zooxanthellae are also a source of food for corals.

Question 4

Which of the following organisms is least likely to be responsible for bioerosion?

Accepted Answer

Algae are primarily photosynthetic organisms and are not typically involved in bioerosion, which is the process of breaking down hard substrates like rocks and coral by living organisms.

Question 5

In addition to zooxanthellae,what is the other important primary producer in a coral reef?

Accepted Answer

Turf algae are important primary producers in coral reefs, providing a significant source of energy and nutrients for the ecosystem.

Question 6

Which of the following is not used directly by corals for nutrition?

Accepted Answer

Corals do not directly use photosynthesis for nutrition. Instead, the zooxanthellae living within their tissues perform photosynthesis, producing oxygen and organic compounds that nourish the coral.

Question 7

The expulsion of zooxanthellae due to unfavorable conditions is called:

Accepted Answer

The expulsion of zooxanthellae due to unfavorable conditions is called bleaching. This occurs when environmental stressors, such as increased water temperature or pollution, cause coral to expel their symbiotic algae (zooxanthellae), resulting in a pale or white appearance.

Question 8

Reef-building corals grow only in shallow water because:

Accepted Answer

Zooxanthellae are photosynthetic algae that live inside the coral and provide the coral with energy. They require light for photosynthesis and therefore corals can only grow in shallow water where sunlight can penetrate.

Question 9

Zooxanthellae are essential to reef-building corals because they:

Accepted Answer

Zooxanthellae are photosynthetic algae living inside the tissues of reef-building corals. They provide the coral with organic nutrients and also help in the deposition of the calcium-carbonate skeleton, which is essential for building the reef structure. Without zooxanthellae, corals cannot survive and grow properly.

Question 10

Eutrophication is very detrimental to the development of coral since it increases:

Accepted Answer

Eutrophication increases the amount of nutrients in the water, which leads to the overgrowth of algae. The algae blocks sunlight and deprives the coral of the energy it needs to survive. Additionally, the decomposition of the excess algae leads to a depletion of oxygen in the water, which can further harm the coral.

Question 11

Spur-and-groove formations,or buttresses,appear to be the result of:

Accepted Answer

Spur-and-groove formations, also known as buttresses, are the result of wind and waves eroding the limestone rock along coastlines. The rock is eroded into a series of ridges (spurs) and channels (grooves) that can be seen both above and below the waterline.

Question 12

Atolls actually start as a:

Accepted Answer

Atolls start as fringing reefs that continue to grow upward while sinking at the same time, eventually forming coral-covered islands that surround a central lagoon. As the island continues to sink, only the reef and lagoon remain, resulting in the formation of an atoll.

Question 13

Reef-building corals are cnidarians that are characterized by:

Accepted Answer

Reef-building corals are cnidarians that only have a polyp stage. They form colonies of polyps that work together to build a hard external skeleton, which forms coral reefs.

Question 14

A primary requirement for coral reef development that determines where they can develop is:

Accepted Answer

The presence of a hard substrate is a primary requirement for coral reef development as this is where the coral larvae settle and attach themselves. Without a hard surface to attach to, coral reefs cannot develop. Salinity levels, sediment availability, grazers, and mucous production are all factors that can affect the health and growth of coral reefs, but they are not the primary requirement for their development.

Question 15

The most common type of coral reefs around the world are:

Accepted Answer

Fringing reefs are the most common type of coral reef around the world. They are located close to the shore and directly attached to the coastline or islands. This type of reef is characterized by shallow lagoons and a narrow, steeply sloping reef crest.

Question 16

Fringing and barrier reefs develop:

Accepted Answer

Fringing and barrier reefs typically develop along a coast, especially in tropical regions where the conditions are favorable for the growth of coral.

Question 17

Planula is the name given to:

Accepted Answer

Planula refers to the free-swimming larvae of corals, which eventually settle on a substrate and develop into mature coral polyps.

Question 18

In a typical fringing reef,most of the living coral is found on the:

Accepted Answer

The answer of In a typical fringing reef,most of the...

Question 19

Most atolls are found in the:

Accepted Answer

Most atolls are found in the Indo-West Pacific region, which includes areas such as the Maldives, Fiji, and the Great Barrier Reef. Atolls are formed when coral reefs build up around the edges of volcanic islands, and the Indo-West Pacific region has the highest concentration of volcanoes in the world, providing ideal conditions for atoll formation.

Question 20

Generally,an important distinction between barrier and fringing reefs is that barrier reefs:

Accepted Answer

Barrier reefs develop farther away from land compared to fringing reefs. They are separated from the shoreline by a lagoon and often run parallel to the coast. Barrier reefs are found in various locations around the world, including the Pacific and Caribbean, and can develop from a variety of coral structures, not just atolls. While they may not have a visible reef flat, they can have a wider and deeper lagoon than fringing reefs.

Quiz 14: Coral Reefs