Question 1

Leopard seals feed on emperor penguins, which feed on secondary consumers. Which trophic level would the leopard seal occupy in this food web? ​

Accepted Answer

As the leopard seal feeds on emperor penguins, which are secondary consumers, it would occupy the fourth trophic level, making it a quaternary consumer.

Question 2

The colonization of Glacier Bay, Alaska by lichen and mosses allowed the growth on the mountain avens, a(n)____ species. ​

Accepted Answer

The answer of The colonization of Glacier Bay, Alaska by...

Question 3

What is the relationship between species richness and recovery from natural disturbances? ​

Accepted Answer

Communities with more diversity recover more rapidly from natural disturbances. This is because diverse communities are more resilient to disturbances as they have a variety of species that can potentially fill in ecological niches left empty by disturbance. Additionally, diverse communities may have more functional redundancy, where different species have similar roles in the ecosystem, allowing for ecosystem processes to continue even if some species are lost due to disturbance.

Question 4

Which trophic level would be best represented by saprophytic fungi? ​

Accepted Answer

Saprophytic fungi act as decomposers, breaking down dead organic matter and recycling nutrients back into the ecosystem. They do not consume living organisms, so they are not considered primary, secondary, or tertiary consumers. They also do not use photosynthesis to produce their own food, so they are not primary producers.

Question 5

Tertiary consumers feed directly on _____. ​

Accepted Answer

The answer of Tertiary consumers feed directly on _____. ​
...

Question 6

Saltmarsh cordgrass is known as a(n)_____ because patches slow the velocity of incoming tides and stabilize stormy beach habitat. ​

Accepted Answer

Saltmarsh cordgrass, also known as Spartina alterniflora, is a foundation species because it plays a critical role in building and stabilizing the ecosystem it inhabits. Its dense root system helps to anchor the soil, prevent erosion, and create habitat for a variety of organisms. The patches of cordgrass also slow down the velocity of incoming tides, which helps to protect the ecosystem from storm surges and aids in sediment deposition.

Question 7

According to the intermediate disturbance hypothesis, species richness is greatest in communities that experience ____. ​

Accepted Answer

The intermediate disturbance hypothesis suggests that moderate levels of disturbance can promote species diversity by creating opportunities for colonization and reducing competition among species. Too much disturbance (option C) can eliminate species, while too little disturbance (options A and E) can allow dominant species to outcompete others. High temperatures (option B) are not directly related to disturbance levels and do not necessarily promote species diversity.

Question 8

In a study examining the effects of disturbances and recruitment on the growth of coral in a portion of the Great Barrier Reef, researchers concluded that changes in the coral colonies are ____. ​

Accepted Answer

The study examined both disturbances (external factors) and recruitment (internal factors), suggesting that both external and internal factors affect the growth of coral colonies. Therefore, the changes observed are due to both external and internal factors. The answer D is incorrect as the study does not suggest human interference as the sole cause of changes in coral colonies. Answer E is also incorrect as the study examined the effects of disturbances and recruitment on the growth of coral colonies, implying that changes can indeed be observed after disturbances.

Question 9

Sympatric populations are able to coexist without competing for resources due to morphological differences known as ____. ​

Accepted Answer

Character displacement refers to the evolutionary divergence in morphology or behavior between two species that occupy the same habitat and compete for the same resources. This allows them to coexist through reduced competition for resources. Niche differentiation and resource partitioning also contribute to coexistence, but do not necessarily involve morphological differences. Mimics and parasitoids are unrelated concepts.

Question 10

Which event can be followed by primary succession? ​

Accepted Answer

Primary succession occurs in lifeless areas where there is no soil, such as after a volcanic eruption, which creates new land or sterilizes the existing environment.

Question 11

More _____ need to be studied in order to find out whether interspecific competition strongly influences the species composition and structure of most communities. ​

Accepted Answer

The answer of More _____ need to be studied in...

Question 12

An example from the text contrasts two forests, each with 10 species and a total of 50 trees. In the first forest, 39 of the 50 trees represent the dominant species. The second forest has 5 of each of the 10 different species. What conclusion can be drawn regarding these two forests? ​

Accepted Answer

The second forest has an even distribution of the 10 species, which indicates a higher level of diversity compared to the first forest where one species dominates. Therefore, the second forest is more diverse than the first. There is no evidence presented in the text to suggest human interference in either forest, and the number of animal species is not discussed.

Question 13

A community in which many species are involved in a food web is ____. ​

Accepted Answer

A community with many species involved in a food web is more stable since organisms have more than a single food source, reducing the impact of disturbances or changes in one species on the entire community. This is known as the principle of ecological resilience.

Question 14

Which trophic level would be best represented by an herbivorous rabbit? ​

Accepted Answer

Herbivorous rabbits feed on plants, which makes them primary consumers. They are the first level of consumers in the food chain, feeding on primary producers (plants) and being preyed upon by secondary consumers (animals that feed on herbivores).

Question 15

How can predators influence the species richness and structure of communities? ​

Accepted Answer

Predators reduce the population sizes of their prey, which can lead to a reduction in competition within the community. This can then allow for the coexistence of a greater number of species, thus increasing species richness. Additionally, the removal of certain prey species by predators can lead to changes in the relative abundance and dominance of other species, influencing the community structure. Therefore, predators have a significant impact on the species richness and structure of communities by controlling the abundance and distribution of their prey.

Question 16

A climax community is ____. ​

Accepted Answer

A climax community is relatively stable, meaning it has reached a steady state in terms of species composition and environmental conditions. It is the endpoint of succession, where the community has reached its maximum potential in terms of species diversity and productivity. It can be the result of either primary or secondary succession, and it may or may not have high species diversity depending on the specific community. It is not necessarily dominated by r-selected species.

Question 17

Which best describes a dominant species? ​

Accepted Answer

A dominant species is defined as a species that has a high relative abundance in an ecosystem or community, meaning it is very common compared to other species in that area. This does not necessarily mean that it is the only species present, or that it has low genetic diversity or high species richness.

Question 18

Which sequence lists the correct order of dominant plants in the ecological succession in Glacier Bay, Alaska? ​

Accepted Answer

The correct sequence for ecological succession in Glacier Bay, Alaska, starts with pioneer species like lichens and moss, which prepare the ground for further colonization. This is followed by the growth of shrubs, then young conifers, and finally, the area is dominated by established spruce and hemlock forests. This sequence reflects the typical progression from pioneer species to a mature forest ecosystem in this region.

Question 19

Periwinkle snails prefer to feed on the green alga Enteromorpha . In tide pools, Enteromorpha , which other alga species, while in areas exposed at low tide, the red alga Chondrus outcompetes Enteromorpha . How did these feeding and competing interactions affect the algal populations? ​

Accepted Answer

The answer of Periwinkle snails prefer to feed on the...

Question 20

What was the overall effect of removing the predatory sea star Pisaster ochraceus from its food web? ​

Accepted Answer

Removing the predatory sea star Pisaster ochraceus led to a decrease in species richness because mussels, which are their prey, were able to outcompete other species for space, leading to a decline in the diversity of species in that habitat.

Quiz 53: Population Interactions and Community Ecology

Leopard seals feed on emperor penguins, which feed on secondary consumers. Which trophic level would the leopard seal occupy in this food web?

The colonization of Glacier Bay, Alaska by lichen and mosses allowed the growth on the mountain avens, a(n) ____ species.

What is the relationship between species richness and recovery from natural disturbances?

Which trophic level would be best represented by saprophytic fungi?

Tertiary consumers feed directly on _____.

Saltmarsh cordgrass is known as a(n) _____ because patches slow the velocity of incoming tides and stabilize stormy beach habitat.

According to the intermediate disturbance hypothesis, species richness is greatest in communities that experience ____.

In a study examining the effects of disturbances and recruitment on the growth of coral in a portion of the Great Barrier Reef, researchers concluded that changes in the coral colonies are ____.

Sympatric populations are able to coexist without competing for resources due to morphological differences known as ____.

Which event can be followed by primary succession?

More _____ need to be studied in order to find out whether interspecific competition strongly influences the species composition and structure of most communities.

An example from the text contrasts two forests, each with 10 species and a total of 50 trees. In the first forest, 39 of the 50 trees represent the dominant species. The second forest has 5 of each of the 10 different species. What conclusion can be drawn regarding these two forests?

A community in which many species are involved in a food web is ____.

Which trophic level would be best represented by an herbivorous rabbit?

How can predators influence the species richness and structure of communities?

A climax community is ____.

Which best describes a dominant species?

Which sequence lists the correct order of dominant plants in the ecological succession in Glacier Bay, Alaska?

Periwinkle snails prefer to feed on the green alga Enteromorpha . In tide pools, Enteromorpha , which other alga species, while in areas exposed at low tide, the red alga Chondrus outcompetes Enteromorpha . How did these feeding and competing interactions affect the algal populations?

What was the overall effect of removing the predatory sea star Pisaster ochraceus from its food web?