Question 1

Which is the dominant greenhouse gas leading to global warming?

Accepted Answer

CO₂ is the dominant greenhouse gas leading to global warming. While other greenhouse gases like CH₄ and NO₂ have higher warming potentials than CO₂, the concentration of CO₂ in the atmosphere is much higher, and it persists for a longer time. H₂O also has a significant contribution to the greenhouse effect, but its concentration is largely controlled by other factors such as temperature and air circulation.

Question 2

What type of species,if removed from the community,could lead to the collapse of the entire community?

Accepted Answer

Keystone species are those species whose presence or absence greatly affects the entire community. These species have a disproportionate impact on the community compared to their abundance. They help maintain the structure and functioning of the ecosystem. If a keystone species is removed, it can lead to the collapse of the entire community as the ecological balance is disrupted.

Question 3

The Asian kudzu bug (Megacopta cribaria)arrived in Atlanta in 2009 and is quickly spreading across the South.In addition to eating kudzu,it also eats soybeans and can decimate entire crops.The kudzu bug is a type of ________ species.

Accepted Answer

The sentence states that the Asian kudzu bug is spreading rapidly and can cause harm to crops. This behavior is indicative of an invasive species, which is a non-native species that has the potential to cause harm to the environment, economy, or human health.

Question 4

What is the term used to describe relatively small areas with unusually high concentrations of species found there and nowhere else,including many species in high risk of extinction? These areas receive the focus of global conservation efforts.

Accepted Answer

Biodiversity hot spots are areas that have a high concentration of unique and endangered species. These areas have become a focus of global conservation efforts to preserve biodiversity. The other answer options are not specific to describing these areas.

Question 5

What category describes a species that,while not presently at risk of extinction,could likely be at risk of extinction in the near future?

Accepted Answer

A threatened species is one that is likely to become endangered in the near future if the factors causing the decline of the population are not addressed. This category provides an early warning sign for species at risk of extinction and allows for conservation efforts to be implemented before the population becomes critically low. An endangered species is already at a high risk of extinction, while a species of concern may have some indication of potential threats but does not meet the criteria for being threatened or endangered. Endemic species are those that are native to a particular region and are not necessarily at risk of extinction.

Question 6

The responsible management (use and conservation)of the earth's resources indefinitely is called ________.

Accepted Answer

Sustainable development refers to the responsible management of the earth's resources in a way that meets the needs of the present without compromising the ability of future generations to meet their own needs. The other choices may be related to environmental conservation or management, but do not specifically refer to the concept of indefinite responsible resource management.

Question 7

An age pyramid with a broad base that quickly slopes up to a narrow top would be indicative of ________.

Accepted Answer

A broad base indicates a high proportion of younger individuals, which is typical of developing nations that are experiencing high birth rates and have a large population of children. The quick slope towards a narrow top indicates higher mortality rates or lower life expectancies, which is also common in developing nations. Industrialized nations typically have a more even distribution of ages, with a smaller proportion of children and a larger proportion of older individuals. A population with a high average age would have a pyramid that is narrower at the base and wider towards the top, indicating a larger proportion of older individuals.

Question 8

The use of multiple forms of pest control including biological,chemical,and the planting of pest-resistant crops is a strategy commonly called ________.

Accepted Answer

Integrated pest management (IPM) is a strategy that involves using multiple methods of pest control, including biological, chemical, and cultural control methods, as well as the use of pest-resistant crops. The goal of IPM is to minimize the use of harmful pesticides and to control pests in a sustainable and environmentally-friendly way. It involves monitoring pest populations and making informed decisions about the most effective and least harmful methods of control.

Question 9

A sudden natural catastrophe resulting in massive die-offs would be categorized as a density-________ limiting factor.

Accepted Answer

Density-independent limiting factors are those that affect a population regardless of its density, such as natural disasters (e.g., floods, fires). These events can cause massive die-offs without regard to how many individuals are in the population.

Question 10

There have been several mass extinctions in the planet's history,such as the extinction of the dinosaurs,but the current mass extinction is different.Greater numbers of species are now going extinct faster than ever before.Also unique to the current mass extinction is the cause.What is causing the current mass extinction?

Accepted Answer

The current mass extinction is largely caused by human activities such as habitat destruction, pollution, hunting, and introduction of non-native species.

Question 11

Human birth rate peaked in the 1980s and has been slowly declining ever since.How is this expected to affect our population size over the next several decades?

Accepted Answer

The human population is expected to continue growing because the total number of people of reproductive age is still increasing, even though the birth rate per individual is declining. This means the overall number of births can still rise or remain high enough to increase population size, but the rate of growth will slow down compared to previous decades.

Question 12

How does an increase in atmospheric greenhouse gases increase global temperatures?

Accepted Answer

Greenhouse gases trap heat in the atmosphere, preventing some of it from escaping into space. This leads to an overall increase in global temperatures.

Question 13

What can a human population's age pyramid tell you about current and future needs?

Accepted Answer

A human population's age pyramid can show both the current needs (such as how many schools to build or close down based on the number of children) and future needs (such as how many workers will be needed to support retirees). This is because it provides information on the age distribution of the population, which can be used to predict future demographic trends and plan accordingly.

Question 14

A dispersion pattern refers to ________.

Accepted Answer

A dispersion pattern refers to the spacing of organisms throughout a habitat. It describes how individuals of a population are distributed in relation to one another. This can be clumped, uniform, or random, depending on factors such as resource availability and social behavior. Density, extinction rates, and species diversity are not necessarily related to dispersion patterns.

Question 15

What are the main causes of biodiversity loss?

Accepted Answer

The main causes of biodiversity loss are habitat destruction, overharvesting, invasive species, pollution, and climate change. All of these factors contribute to the depletion of species and their habitats, leading to a significant reduction in biodiversity. Each factor on its own can have a devastating impact on ecosystems, but the combined effects are particularly concerning. It is crucial to address all of these causes in order to effectively preserve biodiversity.

Question 16

Which growth model would you expect to see in a stable population?

Accepted Answer

A stable population is characterized by a balance between birth and death rates, which is more accurately represented by a logistic growth model. The logistic model has a sigmoidal (S-shaped) curve, which levels off as the population reaches its carrying capacity, reflecting the limitations on resources and environmental factors that prevent unlimited growth. The other growth models (speculative, factorial, exponential) are not relevant to stable populations.

Question 17

Using sunflower plants to naturally remove heavy toxins from contaminated soil is an example of ________.

Accepted Answer

The use of sunflower plants to remove heavy toxins from contaminated soil is an example of bioremediation, which is the use of living organisms to remove or neutralize pollutants from a contaminated site. Land conservancy refers to the preservation of natural land and habitats, the green revolution refers to the increase in agricultural productivity in the mid-20th century, and biomagnification refers to the process where toxin levels increase as they move up the food chain.

Question 18

The buildup of soil on bare rock by the decomposition of early colonizers is characteristic of ________ succession.

Accepted Answer

Primary succession refers to the gradual buildup of soil on bare rock by the decomposition of early colonizers such as lichens and mosses. This process eventually leads to the development of a stable ecosystem with more complex organisms.

Question 19

What is the name of the model of maximum rate of population growth?

Accepted Answer

The model of maximum rate of population growth is known as the exponential model, where the rate of growth is proportional to the current population size.

Question 20

At what level is biodiversity often studied and measured?

Accepted Answer

Biodiversity can be studied and measured at multiple levels, including the diversity of genes within a population (level of genetic diversity), the diversity of species within a community (level of species diversity), and the diversity of ecosystems on the planet (level of ecosystem diversity). Therefore, option D, "All of the above," is the correct answer.

Quiz 12: Ecology