Question 1

The plants and animals now present on acreage from which the trees were removed ten years earlier represent
A) primary succession.
B) a climax forest.
C) pioneer species.
D) secondary succession.
E) species introduction.

Accepted Answer

The presence of plants and animals on the acreage from which trees were removed ten years earlier indicates that secondary succession has occurred. When an existing community is disturbed, secondary succession takes place, and new plants and animals colonize the area. This is different from primary succession, where a community forms on a completely barren area where no living organisms existed before. The term "climax forest" refers to the most stable and diverse stage of ecological development for a particular climate and region. Pioneer species refer to the first organisms to colonize a new or disturbed habitat. Species introduction refers to intentionally or unintentionally introducing a non-native species into an ecosystem.

Question 2

Most organisms are dependent upon plants because
A) plants produce oxygen as a by-product of photosynthesis.
B) as producers, they form the base of food chains.
C) they function to prevent erosion and reduce desertification.
D) as they remove carbon dioxide from the atmosphere, they reduce the problems generated by the greenhouse effect.
E) all of these apply.

Accepted Answer

Plants are crucial for life on Earth as they produce oxygen, form the base of food chains, prevent erosion, and help mitigate the greenhouse effect by absorbing carbon dioxide.

Question 3

An array of organisms together with their physical environment is which of the following?
A) population
B) community
C) ecosystem
D) biosphere
E) landscape

Accepted Answer

An ecosystem is a community of living organisms in conjunction with the nonliving components of their environment, interacting as a system.

Question 4

Which of the following represents an early stage in primary succession?
A) pine trees
B) mosses and lichen of bare rock
C) weedy annual plants in an open field
D) climax species in succession
E) fields of food crops

Accepted Answer

Mosses and lichen of bare rock represent an early stage in primary succession because they are the first organisms to colonize a newly formed or exposed ecosystem. They are well adapted to grow in an environment with little or no soil, and their presence helps to break down the rock surface to create soil for other plants to grow.

Question 5

The keystone species in a Pacific Northwest Old Growth Forest
A) is the Spotted owl, that preys on rodents.
B) are the mice that feed on mushrooms and truffles.
C) are the Douglas fir trees that are dominant species.
D) are the Douglas squirrels that spread the seeds of the Douglas fir.
E) are the piliated woodpeckers that nest in Douglas fir.

Accepted Answer

The answer of The keystone species in a Pacific Northwest...

Question 6

Two species of closely related squirrels both feed on acorns produced by oak trees.One species feed exclusively near the top of the tree and the other feeds exclusively towards the bottom of the tree.This is an example of
A) competitive exclusion.
B) resource partitioning.
C) mutualism.
D) commensalism.
E) mimicry.

Accepted Answer

This is an example of resource partitioning, where closely related species divide a resource (in this case, acorns from oak trees) based on different traits or niches, in order to reduce competition for the shared resource.

Question 7

In a natural community,the primary consumers are
A) herbivores.
B) carnivores.
C) detritivores.
D) decomposers.
E) producers.

Accepted Answer

Primary consumers are typically herbivores which eat plants as their primary source of energy in the food chain.

Question 8

The first plant to colonize the plains of Mt St Helens after this volcano erupted in 1980 was a prairie lupine.The prairie lupine is an example of
A) a secondary successor.
B) a pioneer species.
C) a keystone species.
D) an exotic species.
E) more than one of these.

Accepted Answer

The prairie lupine is the first plant to colonize the plains of Mt St Helens, making it a pioneer species that initiates the process of primary succession.

Question 9

The Venus flytrap receives its nitrogen by trapping and digesting insects.This is a type of
A) commensalism.
B) mutualism.
C) competition.
D) predation.
E) parasitism.

Accepted Answer

The Venus flytrap trapping and digesting insects for its nutrition is a clear case of predation, where the predator gains nutrients by killing and consuming the prey.

Question 10

Considering the traditional view of ecological succession,which of the following plants would most likely be a pioneer species in a primary succession event?
A) an oak tree that produces acorns dispersed by squirrels
B) a snapdragon flower pollinated by bees
C) a dandelion which produces seeds asexually and disperses seeds by the wind
D) it could be any of these
E) it couldn't be any of these

Accepted Answer

Pioneer species are typically plants that are adapted to harsh and unstable environments, and have a high reproductive rate and effective dispersal mechanisms. The dandelion fits these criteria, as it produces large numbers of seeds that are easily dispersed by the wind and can colonize bare soil quickly. Oak trees and snapdragon flowers require more stable and nutrient-rich environments, and are more likely to be intermediate or climax species in a succession event.

Question 11

Secondary succession can occur
A) after a fire.
B) on a new sand dune.
C) on bare rock.
D) immediately after the formation of a manmade lake.
E) on a glacier.

Accepted Answer

Secondary succession occurs after a disturbance that leaves behind a remaining soil layer, and a fire can completely strip an area of vegetation but leave behind soil, allowing for secondary succession to occur. The other choices (B, C, D, and E) describe scenarios where primary succession would occur because there is no pre-existing soil layer.

Question 12

Which of the following statements is CORRECT?
A) A population cannot exceed the carrying capacity even temporarily.
B) An organism can occupy more than one trophic level, depending upon the feeding habits of the organism.
C) Once populations of organisms become isolated, they remain so by various types of isolation mechanisms.
D) The limits of a population are all traced to climatic or physical factors.
E) Organisms with different evolutionary backgrounds can occupy the same niche at the same time.

Accepted Answer

An organism can occupy more than one trophic level, depending upon the feeding habits of the organism. Some organisms may act as both predators and prey, or may consume food from different trophic levels, allowing them to occupy multiple levels.

Question 13

Which of the following is an example of an event that would set up the scene for primary succession?
A) a dense landslide of mountain rocks covering an entire valley
B) a fire that burns off all of the surface vegetation
C) an agricultural field that is abandoned
D) a lake that dries up killing all of the aquatic plants
E) all of these set the scene for secondary succession NOT primary succession

Accepted Answer

Primary succession occurs in areas where there is no existing soil, so a landslide that covers an entire valley with rocks would remove any existing soil and thus set the scene for primary succession to begin. The other options all involve some degree of existing soil or vegetation, making them examples of secondary succession rather than primary succession.

Question 14

Which of the following is NOT dependent on the others as a food supply?
A) carnivores
B) herbivores
C) producers
D) detritivores
E) decomposers

Accepted Answer

Carnivores, herbivores, detritivores, and decomposers are all dependent on producers as a food supply since producers, such as plants, are at the base of the food chain and provide the energy for all other organisms. Producers, on the other hand, can generate their own food through photosynthesis and are not dependent on other organisms for their food supply.

Question 15

Many introduced species have had deleterious effects on communities and ecosystems because
A) coevolved parasites and pathogens are absent.
B) the introduced species are long-lived.
C) predators prefer the introduced species, and the local prey therefore proliferate to dangerously high levels.
D) the community from which they came lost an important predator, competitor, or parasite.
E) human beings do not know how to appreciate them.

Accepted Answer

Introduced species often thrive because they lack natural predators, parasites, or pathogens that would normally control their population in their native habitat.

Question 16

Which of the following is a major determinant in which plant species becomes a pioneer species in a primary succession event?
A) the species of plants that preceded it
B) the animals that occupy the area
C) chance events
D) the nature of the existing soils
E) the type of disturbance

Accepted Answer

Chance events play a significant role in determining which plant species become pioneer species in primary succession, as these species are often the first to colonize an area where no soil previously existed, such as after a volcanic eruption or glacial retreat.

Question 17

The primary consumer is also
A) the second link in a food chain.
B) a herbivore.
C) an animal.
D) a herbivore and an animal.
E) the second link in a food chain, a herbivore, and an animal.

Accepted Answer

The primary consumer is the second link in a food chain, as it feeds on producers (plants). It is also a herbivore because it eats plants, and it is an animal.

Question 18

Mistletoe is a plant that grows commonly on the limbs of hawthorn trees and extracts nutrients from its host plant.The relationship between mistletoe and the hawthorn tree is
A) commensalism.
B) mutualism.
C) competition.
D) predation.
E) parasitism.

Accepted Answer

Mistletoe is a parasitic plant that benefits from the nutrients and resources of the host hawthorn tree, while harming the tree by extracting its resources. Therefore, the relationship between mistletoe and the hawthorn tree is parasitism.

Question 19

Detritivores are
A) bacteria.
B) plants.
C) fungi.
D) animals.
E) more than one of these.

Accepted Answer

Detritivores are animals that feed on dead organic matter, such as dead animals or plant material. Examples of detritivores include earthworms, dung beetles, and vultures. While bacteria, plants, and fungi also play roles in decomposition, they are not considered detritivores.

Question 20

Which of the following is a primary consumer?
A) tiger
B) elephant
C) eagle
D) hyena
E) snake

Accepted Answer

Elephants are herbivores that feed on plants, making them primary consumers in the food chain.

Quiz 17: Communities and Ecosystems

The plants and animals now present on acreage from which the trees were removed ten years earlier represent

Most organisms are dependent upon plants because

An array of organisms together with their physical environment is which of the following?

Which of the following represents an early stage in primary succession?

The keystone species in a Pacific Northwest Old Growth Forest

Two species of closely related squirrels both feed on acorns produced by oak trees.One species feed exclusively near the top of the tree and the other feeds exclusively towards the bottom of the tree.This is an example of

In a natural community,the primary consumers are

The first plant to colonize the plains of Mt St Helens after this volcano erupted in 1980 was a prairie lupine.The prairie lupine is an example of

The Venus flytrap receives its nitrogen by trapping and digesting insects.This is a type of

Considering the traditional view of ecological succession,which of the following plants would most likely be a pioneer species in a primary succession event?

Secondary succession can occur

Which of the following statements is CORRECT?

Which of the following is an example of an event that would set up the scene for primary succession?

Which of the following is NOT dependent on the others as a food supply?

Many introduced species have had deleterious effects on communities and ecosystems because

Which of the following is a major determinant in which plant species becomes a pioneer species in a primary succession event?

The primary consumer is also

Mistletoe is a plant that grows commonly on the limbs of hawthorn trees and extracts nutrients from its host plant.The relationship between mistletoe and the hawthorn tree is

Detritivores are

Which of the following is a primary consumer?