Question 1

Oxygen levels in our atmosphere increased approximately 2 billion years ago from early oceanic organisms through the process of ______.&#10;A) succession&#10;B) respiration&#10;C) photosynthesis&#10;D) decomposition

Accepted Answer

The process of photosynthesis, which involves the absorption of carbon dioxide and release of oxygen, was responsible for increasing oxygen levels in Earth's atmosphere approximately 2 billion years ago. This was mainly due to the evolution of cyanobacteria and other photosynthetic organisms in the ocean.

Question 2

The driving force behind practically all life on Earth is:&#10;A) the sun&#10;B) water&#10;C) carbon dioxide&#10;D) oxygen&#10;E) nitrogen

Accepted Answer

The sun provides energy through photosynthesis, which is essential for the growth and survival of almost all living organisms on Earth. Without the energy provided by the sun, life as we know it would not exist.

Question 3

What types of plants are common in arid climates?&#10;A) xerophytes&#10;B) hydrophytes&#10;C) mesophytes&#10;D) aridophytes

Accepted Answer

Xerophytes are plants that are adapted to survive in arid climates with low precipitation and high temperatures. Examples of xerophytes include cacti, succulents, and certain types of grasses. Hydrophytes are adapted to live in aquatic environments, mesophytes thrive in moderate moisture environments, and aridophytes are not a recognized type of plant.

Question 4

Phytoplankton are _____.&#10;A) herbivores&#10;B) carnivores&#10;C) autotrophs&#10;D) omnivores&#10;E) marine scavengers

Accepted Answer

Phytoplankton are primary producers in aquatic ecosystems, meaning they are autotrophs that produce their own food through photosynthesis.

Question 5

How many trophic levels higher are wolves from grass on the food chain?&#10;A) one&#10;B) two&#10;C) three&#10;D) four

Accepted Answer

Wolves are secondary consumers, meaning they eat primary consumers like herbivores. Grass is a producer, at the first trophic level. Therefore, wolves are two trophic levels higher than grass on the food chain.

Question 6

The highest net primary productivity occurs:&#10;A) in boreal forests&#10;B) in tropical rainforests&#10;C) in tropical grasslands&#10;D) in mid-latitude grasslands

Accepted Answer

Tropical rainforests have the highest net primary productivity due to high levels of precipitation, temperature, and solar radiation. These conditions promote high levels of photosynthesis, resulting in a large amount of plant growth and biomass production.

Question 7

A natural ecosystem operates on:&#10;A) energy flow and matter flow&#10;B) energy cycling and matter cycling&#10;C) energy cycling and matter flow&#10;D) energy flow and matter cycling

Accepted Answer

A natural ecosystem operates on energy flow and matter cycling. Energy flows through the ecosystem from the sun to producers (plants), then to consumers (animals), and finally to decomposers (bacteria and fungi). Matter, such as nutrients, cycles through the ecosystem as it is taken up by producers, passed along the food chain, and returned to the soil through decomposition. Therefore, the best choice that describes the operation of a natural ecosystem is energy flow and matter cycling.

Question 8

Net primary productivity is the _____________.&#10;A) biomass of all plants and animals&#10;B) biomass produced by all the plants&#10;C) biomass produced by all plants minus the mass lost through plant respiration&#10;D) biomass produced by all plants and animals minus mass lost by their respiration

Accepted Answer

Net primary productivity is the amount of biomass produced by all plants in an ecosystem, minus the biomass lost through plant respiration. Therefore, option C is the correct answer. Option A is incorrect because net primary productivity does not include the biomass of animals. Option B is incorrect because it only refers to the biomass produced by plants, without taking into account the biomass lost through respiration. Option D is incorrect because it includes the biomass of animals, which is not part of net primary productivity.

Question 9

The replacement of one type of vegetation by another type of vegetation is known as plant ____.&#10;A) dynamics&#10;B) succession&#10;C) evolution&#10;D) trophic replacement

Accepted Answer

The replacement of one type of vegetation by another type is known as plant succession. Plant dynamics refers to the changes in vegetation, but does not specifically refer to replacement. Evolution refers to genetic changes in populations over time, and trophic replacement refers to the replacement of one group of organisms in a food web with another group.

Question 10

The type of plant succession initiated by a disturbance like fire is called:&#10;A) primary&#10;B) secondary&#10;C) tertiary&#10;D) none of these

Accepted Answer

A disturbance like fire that destroys an existing ecosystem but leaves behind soil and some plant seeds or roots initiates a secondary succession. Primary succession occurs when a completely new habitat, such as bare rock, is colonized for the first time by plants and other organisms. Tertiary succession is not a recognized type of plant succession but instead refers to the restoration of an ecosystem to its pre-disturbance condition.

Question 11

A species that has a wide range of tolerance to most environmental factors is:&#10;A) very sensitive to climatic change&#10;B) found in a wide geographic range&#10;C) found in a narrow geographic range&#10;D) easily stressed

Accepted Answer

The answer of A species that has a wide range...

Question 12

The term biomass in an ecosystem refers to the mass of:&#10;A) all the plants&#10;B) all the animals&#10;C) trees&#10;D) all of the above

Accepted Answer

The answer of The term biomass in an ecosystem refers...

Question 13

An invasion of exotic species to a region sometimes results in increased ___.&#10;A) biomass&#10;B) succession&#10;C) competition&#10;D) all of these&#10;E) none of these

Accepted Answer

The answer of An invasion of exotic species to a...

Question 14

Endemic species are often found:&#10;A) on large continents&#10;B) in coastal marshes&#10;C) on isolated islands&#10;D) in urban areas

Accepted Answer

The answer of Endemic species are often found:&#10;A) on large...

Question 15

Plants that live in wet environments are classified as ___.&#10;A) hypophytes&#10;B) hygrophytes&#10;C) waterphytes&#10;D) epiphytes

Accepted Answer

The answer of Plants that live in wet environments are...

Question 16

All these are a necessary part of a natural ecosystem EXCEPT:&#10;A) producers&#10;B) decomposers&#10;C) abiotic substances&#10;D) omnivores

Accepted Answer

The answer of All these are a necessary part of...

Question 17

A climax community is the highest producer of biomass for an evolving ecosystem.

Accepted Answer

The answer of A climax community is the highest producer...

Question 18

The total energy of an ecosystem decreases at higher trophic levels.

Accepted Answer

The answer of The total energy of an ecosystem decreases...

Question 19

The total biomass of an ecosystem always decrease at higher trophic levels.

Accepted Answer

The answer of The total biomass of an ecosystem always...

Question 20

Amensalism refers to:&#10;A) survival of the fittest&#10;B) two species interacting for mutual benefits&#10;C) one species may inhibit the optimum growth of another&#10;D) none of these

Accepted Answer

The answer of Amensalism refers to:&#10;A) survival of the fittest&#10;B)...

Question 21

In the Arctic, the limiting factor for growth is most likely:&#10;A) wolves&#10;B) precipitation&#10;C) temperature&#10;D) sunlight

Accepted Answer

The answer of In the Arctic, the limiting factor for...

Deck 24: Biogeographic Processes