Question 1

In food webs, toxic chemicals tend to accumulate and concentrate most in the

Accepted Answer

Toxic chemicals tend to accumulate and concentrate as they move up the food chain, a process called biomagnification. This is because each level of the food chain consumes prey that contains toxins, which then accumulate in their bodies. Since top carnivores eat a lot of prey, they tend to have the highest concentration of toxins in their bodies. Therefore, option A is the best choice.

Question 2

The snail kite (Rostrhamus sociabilis) is a specialist that feeds on only one specific type of snail. By comparison, the Mallard Duck (Anas platyrhynchos) is a generalist that feeds on diverse food sources. Whereas the snail kite has a very limited range, the Mallard Duck has a very broad range. The snail kite's diet is an example of a(n)

Accepted Answer

The answer of 
The snail kite (Rostrhamus sociabilis) is a...

Question 3

________ refers to the biotic and abiotic characteristics in the environment that determine species distribution.

Accepted Answer

Limiting factors are environmental conditions that limit the growth, abundance, or distribution of a species within an ecosystem. They can be biotic (like food availability) or abiotic (like temperature or water availability).

Question 4

Lichen are made up of algae and fungi living together. In this relationship, the alga is the produce and for source for the fungus and the fungus provides structure and physical support for the alga. This is an example of which symbiotic relationship?

Accepted Answer

Mutualism is the symbiotic relationship in which both organisms benefit from each other's presence. In this case, the algae and fungi in lichen have a mutually beneficial relationship, with the algae providing food for the fungus and the fungus providing structure and support for the algae.

Question 5

Currently, approximately ________ of cultivated acreage in the United States and Canada is planted for animal consumption

Accepted Answer

Approximately 50% of cultivated acreage in the United States and Canada is planted for animal consumption.

Question 6

Only about ________ of the kilocalories in a trophic level is passed to the next trophic level (e.g. from autotroph to primary consumer).

Accepted Answer

Only about 10% of the energy is passed on to the next trophic level. This phenomenon is known as the 10% rule or the ecological efficiency. The remaining energy is lost as heat during metabolic processes or used for growth and reproduction by organisms at each trophic level.

Question 7

The environment in which an organism resides or is biologically adapted to live is called a(n)

Accepted Answer

The definition given fits the concept of a habitat, which refers to the specific physical and biological features that make up an organism's surroundings and that are necessary for its survival and reproduction. An ecotone is a transition zone between two different ecosystems, a community refers to the populations of different species living within a habitat, and a niche refers to the ecological role and interactions of a species within a community.

Question 8

A consumer, such as a bear, that eats both producers (plants) and consumers (animals) is a

Accepted Answer

An omnivore is a consumer that eats both producers (plants) and consumers (animals). A bear is an example of an omnivore, as it will eat not only plants (such as berries and roots) but also animals (such as fish and mammals).

Question 9

Mistletoe (Phoradendron) infest many taxa of plants, often causing the branches of the host species to become swollen and distorted and making the trees more susceptible to insect infestations. This is an example of which symbiotic relationship?

Accepted Answer

Mistletoe is a parasitic plant that benefits at the expense of its host, causing harm and damage to the host plant. Therefore, this is an example of parasitism.

Question 10

The interacting populations of living plants and animals in a particular location are described as a(n)

Accepted Answer

A community refers to all the populations of different species that live together and interact in a particular location, such as a forest, a coral reef, or a grassland. The term encompasses both the plants and the animals in the ecosystem. Option A, a metapopulation, refers to a group of connected populations of the same species. Option B, an ecosystem, describes both the biotic and abiotic components of an area, and how they interact. Option D, a niche, refers to the unique ecological role and habitat of a particular species within an ecosystem.

Question 11

In coral reefs, clownfish live unharmed among the poisonous tentacles of sea anemones. The sea anemones protect the clownfish from predation, while the clownfish scare off predators, such butterfly fish, which would otherwise eat the anemones. The clownfish may also provide important nutrients to the anemones. This is an example of which symbiotic relationship?

Accepted Answer

This is an example of mutualism, where both species benefit from the relationship. The sea anemones protect the clownfish from predators, and the clownfish scare off predators that would eat the anemones. Additionally, the clownfish may provide important nutrients to the anemones.

Question 12

The proposition that no two species can occupy the same ecological niche is known as the

Accepted Answer

The proposition that no two species can occupy the same ecological niche is known as the competitive exclusion principle. Option A is incorrect as symbiosis is a different concept that refers to the close interaction between two species. Option C refers to the idea that energy flows through ecosystems and is organized into trophic levels, while option D is a broader concept that encompasses the niche concept but also includes other ecological factors.

Question 13

As chemical pesticides move through the trophic pyramid, they may be amplified at each higher level in a process called

Accepted Answer

Biomagnification occurs as chemical pesticides are accumulated and amplified as they move through each level of the trophic pyramid. This can result in dangerously high levels of pesticides in top predators, such as birds of prey, which can have negative impacts on their health and survival. Trophic cascading refers to the indirect effects on lower trophic levels that result from changes in higher trophic levels, and is not directly related to pesticide accumulation. Competitive exclusion refers to the process by which one species excludes another from access to a particular resource, and pyramidal decay is not a recognized ecological process.

Question 14

Consider a simple food chain in which a grasshopper eats grass, the grasshopper is eaten by a frog, and the frog is eaten by a snake. Which of the following is not correctly matched

Accepted Answer

The snake is a secondary consumer since it feeds on the frog, which is a primary consumer. Therefore, the option D is not correctly matched as it states that the snake is a primary consumer.

Question 15

Which of the following would not be a limiting factor for a plant species?

Accepted Answer

The number of predators would affect the survival of the plant's consumers, but would not directly limit the plant's growth or reproduction. A, B, and D are all factors that can directly limit a plant's growth or survival.

Question 16

The specific, unique role that a species performs within a given area is known as a(n)

Accepted Answer

The definition provided in the question matches the definition of a niche, which is the specific role or function that a species has within a particular ecosystem. Ecotone refers to the transitional area between two different ecosystems, habitat refers to the physical environment in which an organism lives, and community refers to the various populations of organisms that inhabit a specific area and interact with each other.

Question 17

From the perspective of energy, which of the following is the most efficient trophic level?

Accepted Answer

The primary producer, such as plants or algae, converts sunlight energy into chemical energy through photosynthesis. This process has a high conversion efficiency, meaning most of the energy is retained within the organism, giving it an efficiency of around 10%. In contrast, each successive trophic level, like primary consumers (herbivores), secondary consumers (carnivores), and tertiary consumers (top predators), has a lower efficiency because much of the energy is lost as heat during metabolic processes. As a result, the energy transfer from one trophic level to the next is usually only about 10%. Therefore, primary producers are the most efficient trophic level when energy is considered.

Question 18

The zonation of flora and fauna along an altitudinal transect similar to that found along latitudinal transects is known as the

Accepted Answer

The life zone concept describes the altitudinal zonation of flora and fauna, similar to how latitudinal zonation is referred to as biomes. The concept proposes that different elevations have distinct ecological zones characterized by their unique assemblage of species adapted to those specific environmental conditions.

Question 19

A black walnut (Juglans nigra) emits a chemical that may kill or inhibit the growth of other nearby shrubs or trees. However, the black walnut is unaffected by this interaction. This is an example of which symbiotic relationship?

Accepted Answer

This relationship is an example of amensalism, where one species is negatively affected while there is no effect on the other species. The black walnut is releasing a chemical that is harmful to the growth of other plants but this does not affect its own growth.

Question 20

Epiphytic plants, such as various species of orchids (Orchidaceae), grow upon another plant, using the plants for physical support, but bringing no harm to the host plant. This is an example of which symbiotic relationship?

Accepted Answer

Epiphytic plants are not harming the host plant, and are only using it for physical support. This is an example of commensalism, where one organism benefits (the epiphytic plant) and the other organism is not affected positively or negatively (the host plant). Therefore, option C is the correct answer.

Quiz 19: Ecosystem Essentials