Question 1

According to the International Union for Conservation of Nature (IUCN), which of the following sequences shows groups with the highest percentage of species in danger of extinction, from most endangered (on the left) to least endangered (on the right)?
A) plants → amphibians → birds
B) amphibians → birds → plants
C) birds → plants → amphibians
D) plants → birds → amphibians

Accepted Answer

According to the IUCN Red List, amphibians are the most threatened group of species, with over 30% of species considered to be at risk of extinction. Birds are the second most threatened group, with approximately 13% of species at risk. Plants, while still facing threats, have a much lower percentage of species in danger of extinction, with only around 3% at risk according to the IUCN. Therefore, the correct sequence from most to least endangered is amphibians, birds, and plants, which is shown in option B.

Question 2

How many years is the average life span of a species on Earth?
A) 1000
B) 100,000
C) 1 million
D) 100 million

Accepted Answer

The average lifespan of a species on Earth is approximately 1 million years, although this can vary widely depending on the species and environmental factors.

Question 3

What is the life span of a species?
A) the span during which a living species is observed in the wild
B) the duration of time that a species doesn't change
C) the span of rock ages over which fossils of a species occur
D) the period of time that it takes for an individual to reach adulthood, reproduce, and die

Accepted Answer

The life span of a species refers to the span of rock ages over which fossils of a species occur, indicating the period during which that species existed on Earth.

Question 4

Which of the following would be most threatened by habitat fragmentation?
A) songbirds
B) lizards
C) mountain lions
D) antelopes

Accepted Answer

Mountain lions would be most threatened by habitat fragmentation due to their large home ranges and need for extensive territories to hunt and live, which are disrupted by fragmentation.

Question 5

-According to this species-area curve for reptiles and amphibians on a West Indian archipelago, how will the number of species living in the area change if the original area was decreased by 50%?
A) +50%
B) −50%
C) −90%
D) −10%

Accepted Answer

The answer of 
-According to this species-area curve for reptiles...

Question 6

What type of curve is depicted in a graph of the relationship between the size of a region and the biodiversity that it can support?
A) habitat loss
B) biomass
C) overexploitation
D) species-area

Accepted Answer

The relationship between the size of a region and the biodiversity it can support is represented by a species-area curve, where the number of species in a given area increases with the size of the area. As the area increases, more habitat types and environmental conditions become available, allowing for the support of a greater variety of species. This relationship is commonly observed across a range of habitats, from small islands to large ecosystems, and can be used to inform conservation and management strategies.

Question 7

Which organism comprises the largest and bottom base level of the trophic pyramid?
A) decomposers
B) producers
C) primary consumers
D) secondary consumers

Accepted Answer

Producers, such as plants and algae, are the foundation of the trophic pyramid and the largest organism at the bottom. This is because they are the first to convert sunlight and nutrients into organic matter, which is then consumed by other organisms in higher trophic levels.

Question 8

-According to this graph, when did the extinction rate in mammals exceed that of birds, if at all?
A) 1600-1649
B) 1700-1749
C) 1800-1849
D) 1900-1949

Accepted Answer

The answer of 
-According to this graph, when did the...

Question 9

Which factor presents the greatest threat to biodiversity?
A) habitat loss or degradation
B) introduction of nonnative species
C) overharvesting
D) pollution

Accepted Answer

Habitat loss or degradation is the primary reason for species extinction, which is the ultimate result of biodiversity loss.  It affects both terrestrial and aquatic habitats, leading to the loss of habitat specialists and the fragmentation of ecosystems, which ultimately leads to the loss of biodiversity. Non-native species, pollution, and overharvesting are also significant threats, but they are usually secondary to loss of habitat.

Question 10

What is the role a species plays in an ecosystem?
A) ecological niche
B) trophic level
C) biophilia
D) biomass

Accepted Answer

The role a species plays in an ecosystem is known as its ecological niche. This includes its interactions with other species and its use of resources within the ecosystem.

Question 11

Over the past 580 million years, how has biodiversity changed?
A) It has smoothly and steadily increased.
B) It has smoothly and steadily increased until the past 100 years or so.
C) It has generally increased but with punctuations in the pattern.
D) It has rapidly increased until it started to rapidly decrease in the past 100 years or so.

Accepted Answer

Over the past 580 million years, biodiversity has generally increased but with punctuations in the pattern. There have been times of rapid diversification followed by mass extinctions, which have contributed to fluctuations in overall biodiversity. In the past 100 years, there has been a rapid decline in biodiversity due to human activities such as habitat destruction, pollution, and climate change.

Question 12

Which group of organisms has the greatest percentage of species in danger of extinction, according to the International Union for Conservation of Nature (IUCN)?
A) plants
B) mammals
C) birds
D) reptiles

Accepted Answer

The answer of Which group of organisms has the greatest...

Question 13

The sudden loss of which organism would necessarily cause the loss of most or all of a food web?
A) producer
B) secondary consumer
C) mutualistic species
D) keystone species

Accepted Answer

A keystone species is one whose presence is critical to maintaining the structure and function of an ecosystem. Their removal can cause a cascading effect of extinctions and disrupt the food web. Removing a producer or secondary consumer may affect some parts of the food web, but it is unlikely to cause the loss of most or all of it. Similarly, a mutualistic species may have important interactions with other species but is unlikely to have such a widespread effect on the food web.

Question 14

At the current rate of habitat destruction, what percentage of all living species will be extinct in 50 years?
A) 1%
B) 10%
C) 25%
D) 50%

Accepted Answer

Estimates suggest that at the current rate of habitat destruction, up to 25% of all living species could be extinct within 50 years. This is due to factors like deforestation, pollution, climate change, and the expansion of human populations into previously wild areas.

Question 15

What role would an owl that eats a seed-eating mouse perform in a food chain?
A) producer
B) primary consumer
C) secondary consumer
D) tertiary consumer

Accepted Answer

The owl would be considered a secondary consumer because it is consuming a mouse that eats seeds, which makes the mouse a primary consumer (consuming a producer).

Question 16

What phenomenon results from the runoff of fertilizers from agricultural and residential areas causing the aquatic algae in bodies of water to grow prolifically?
A) competitive exclusion
B) habitat fragmentation
C) eutrophication
D) overexploitation

Accepted Answer

Eutrophication results from an excess of nutrients in bodies of water, such as nitrogen and phosphorus from fertilizers, causing an explosion in the growth of aquatic algae. This can lead to oxygen depletion and harm or kill other organisms in the ecosystem. Choice A (competitive exclusion) is when one species outcompetes another for resources, which is not related to this phenomenon. Choice B (habitat fragmentation) is the division of habitat into smaller and more isolated patches, which is not related to this phenomenon. Choice D (overexploitation) is the unsustainable use of natural resources, such as hunting or fishing beyond a population's ability to recover, which is not related to this phenomenon.

Question 17

Which threat to biodiversity isn't directly due to humans?
A) loss of habitat due to volcanic activity
B) introduction of nonnative species
C) overexploitation
D) pollution

Accepted Answer

Volcanic activity is a natural occurrence that can result in the loss of habitat and destruction of ecosystems, but it is not directly caused by humans.

Question 18

At the current rate of habitat destruction, tropical rainforests will be reduced to ________ of their original size within 35 years, and ________ of species living there will go extinct.
A) 10%; 50%
B) 1%; 90%
C) 50%; 50%
D) 90%; 95%

Accepted Answer

Tropical rainforests are being destroyed at an alarming rate, but the most widely cited projections suggest that if current trends continue, they could be reduced to about 10% of their original size within the next few decades. This level of destruction is expected to result in the extinction of approximately 50% of the species living in these habitats, due to loss of habitat and the fragmentation of the ecosystems they depend on.

Question 19

What would all individuals of all species living within an area of interest represent?
A) ecosystem
B) community
C) population
D) trophic level

Accepted Answer

A community is defined as all the individuals of different species living within a specific area or ecosystem. An ecosystem refers to the physical and biological components of an environment. A population refers to all the individuals of a particular species living within a specific area. A trophic level refers to the position an organism occupies in a food chain, such as producers, primary consumers, and so on.

Question 20

Most of the energy contained in one trophic level is "lost" when it gets to the next trophic level. What form does the lost energy take?
A) free electrons
B) metabolic heat
C) potential energy, in chemical bonds
D) kinetic energy, in the motion of consumers

Accepted Answer

When energy is transferred from one trophic level to another, a significant amount of it is lost as metabolic heat. This is due to the fact that organisms use a lot of energy to keep themselves alive and to carry out their essential metabolic processes. Some of this energy is lost as heat to the environment, reducing the amount of energy available for the next trophic level.

Quiz 15: Conserving Biodiversity: Community and Ecosystem Ecology

According to the International Union for Conservation of Nature (IUCN) , which of the following sequences shows groups with the highest percentage of species in danger of extinction, from most endangered (on the left) to least endangered (on the right) ?

How many years is the average life span of a species on Earth?

What is the life span of a species?

Which of the following would be most threatened by habitat fragmentation?

-According to this species-area curve for reptiles and amphibians on a West Indian archipelago, how will the number of species living in the area change if the original area was decreased by 50%?

What type of curve is depicted in a graph of the relationship between the size of a region and the biodiversity that it can support?

Which organism comprises the largest and bottom base level of the trophic pyramid?

-According to this graph, when did the extinction rate in mammals exceed that of birds, if at all?

Which factor presents the greatest threat to biodiversity?

What is the role a species plays in an ecosystem?

Over the past 580 million years, how has biodiversity changed?

Which group of organisms has the greatest percentage of species in danger of extinction, according to the International Union for Conservation of Nature (IUCN) ?

The sudden loss of which organism would necessarily cause the loss of most or all of a food web?

At the current rate of habitat destruction, what percentage of all living species will be extinct in 50 years?

What role would an owl that eats a seed-eating mouse perform in a food chain?

What phenomenon results from the runoff of fertilizers from agricultural and residential areas causing the aquatic algae in bodies of water to grow prolifically?

Which threat to biodiversity isn't directly due to humans?

At the current rate of habitat destruction, tropical rainforests will be reduced to of their original size within 35 years, and of species living there will go extinct.

What would all individuals of all species living within an area of interest represent?

Most of the energy contained in one trophic level is "lost" when it gets to the next trophic level. What form does the lost energy take?