Environmental Science

A food chain represents a linear sequence of organisms where nutrients and energy are transferred from one to another. Option B correctly identifies a producer (plants) being eaten by a primary consumer (deer), which is then eaten by a secondary consumer (bobcat).

In food webs and food chains, arrows are used to indicate the direction of energy transfer from the organism being eaten to the organism that consumes it.

Sustainable cities focus on long-term viability by integrating economic, social, and environmental goals. This approach aims to improve the quality of life and standard of living for all residents.

Automobiles are generally less energy-efficient per passenger-mile compared to mass transit options like buses or trains, which can carry many more people simultaneously.

Smart growth is an urban planning strategy that promotes compact, transit-oriented development. Building up rather than out helps preserve open space and reduces reliance on cars.

Urbanization is primarily driven by economic opportunities. Cities typically offer a wider variety of jobs and industries compared to rural areas, which often rely on agriculture.

A limiting factor is any resource or environmental condition that restricts the growth, abundance, or distribution of an organism or a population. Predation by wolves directly limits the elk population size.

Population density is calculated as individuals divided by area. A: 35/10 = 3.5; B: 40/20 = 2; C: 1/1 = 1; D: 50/30 = 1.67. Option A has the highest density.

Sampling is a standard method used in ecology to estimate population sizes when it is impractical or impossible to count every single individual in a large area.

Migration is the seasonal movement of animals from one region to another, often triggered by changes in food availability or climate, such as birds traveling south for winter.

A community consists of all the different populations of species that live and interact in a particular area. An ecosystem includes the community plus the abiotic (non-living) factors.

Ecological footprint measures the amount of biologically productive land and water required to provide the resources a person consumes and to absorb their waste. Developed nations like Canada typically have much higher footprints than developing nations.

In the demographic transition model, the transitional stage is characterized by a significant drop in death rates due to improvements in medicine, sanitation, and food supply, while birth rates remain high.

Graphs that show the distribution of a population by age and sex are universally referred to as age structure diagrams or population pyramids.

High population growth occurs when the birth rate is high and the death rate is low. High life expectancy (low death rate) and low infant mortality (more children surviving) contribute to this.

The Industrial Revolution led to major advancements in technology, medicine, and agriculture, which significantly reduced death rates and allowed the human population to grow exponentially.

Humans are biologically adapted to consume both plant and animal matter, which classifies them as omnivores.

According to the 10% rule in ecology, only about 10% of the energy at one trophic level is passed to the next. Therefore, approximately 90% of the energy is lost as heat or used for metabolic processes.

Primary succession occurs in an area where no soil exists, such as on bare rock left by a landslide or retreating glacier. Secondary succession occurs where soil is already present.

The United Nations is an international organization headquartered in New York City that works to maintain international peace and security and solve global economic and humanitarian problems.

The 1960s and 1970s saw a surge in public awareness regarding environmental issues, leading to the creation of major US legislation like the Clean Air Act and the Clean Water Act. Later decades focused more on amendments or specific niche regulations rather than the foundational policy framework.

Ecolabeling is a practice where manufacturers label products to inform consumers about their environmental impact. These specific certifications help consumers identify products that meet certain sustainability or ethical standards.

A cost-benefit analysis is a decision-making tool that weighs the positive outcomes (benefits) against the negative consequences (costs) of a specific action. It is widely used in economics and environmental policy to determine if a project is worth pursuing.

Carcinogens are specific types of chemical or physical agents that have the potential to cause cancer in living tissue. Other options like teratogens cause birth defects, and neurotoxins damage the nervous system.

An emerging disease is one that has recently appeared in a population or is rapidly increasing in incidence or geographic range. Pandemics refer to the scale of spread, while infectious simply describes the nature of the transmission.

A pathogen is any biological agent, such as a virus, bacterium, or fungus, that causes disease in its host. Toxicants are generally chemical substances, whereas pandemics refer to the widespread occurrence of a disease.

Risk assessment is the systematic process of evaluating the potential risks that may be involved in a projected activity or undertaking. It involves identifying hazards and estimating the likelihood of harm.

Infants and young children are more sensitive to environmental hazards because their bodies are still developing and their metabolic processes are different from those of adults. They often have higher intake rates relative to their body weight.

Biological hazards are threats to human health caused by living organisms or their products. This includes viruses, bacteria, parasites, and other pathogens.

Photosynthesis is the process by which plants use sunlight to convert water and carbon dioxide into oxygen and glucose (a carbohydrate). The inputs are light, water, and CO2, while the outputs are oxygen and sugar.

Nutrients are chemical substances that an organism needs to sustain life, grow, and reproduce. Examples include nitrogen, phosphorus, and carbon.

Condensation is the process where water vapor cools and turns back into liquid water, often forming clouds or precipitation. Evaporation is the opposite, where liquid turns to vapor.

The asthenosphere is a semi-fluid, ductile layer of the upper mantle located below the lithosphere. The lithospheric plates move or 'float' on top of this plastic-like layer.

Water is called the universal solvent because its polar molecular structure allows it to dissolve a wider variety of substances than almost any other liquid.

An atom is the smallest unit of an element that retains the chemical properties of that element. Molecules and compounds are made up of multiple atoms bonded together.

The open ocean zone begins at the edge of the continental shelf and extends outward. It is the vast, deep part of the ocean beyond the neritic zone.

The photic zone is the upper layer of an aquatic ecosystem where sunlight penetrates, allowing photosynthesis to occur. Because producers can thrive here, it supports a higher density of life compared to the aphotic or benthic zones.

The aphotic zone is the deeper part of an aquatic ecosystem where sunlight is insufficient for photosynthesis. Without light, producers cannot survive, which limits the food web in this region.

Net primary productivity in aquatic ecosystems is primarily limited by the availability of sunlight (for photosynthesis) and essential nutrients (like nitrogen and phosphorus) that producers need to grow.

Coral reefs are among the most productive ecosystems on Earth, often referred to as the rainforests of the sea. They support high levels of biodiversity and have very high rates of primary production.

Weather refers to the short-term, day-to-day conditions of the atmosphere, such as temperature, humidity, and precipitation. Climate refers to the long-term averages of these conditions over many years.

Species Survival Plans (SSPs) are programs designed to manage the breeding of endangered species in captivity to ensure their survival and potential reintroduction into the wild.

CITES (Convention on International Trade in Endangered Species) and the Convention on Biological Diversity are international treaties aimed at protecting species and ecosystems from overexploitation and habitat loss.

Habitat fragmentation occurs when large, continuous habitats are divided into smaller, isolated patches. This separation prevents species from moving between areas, which can lead to population declines.

Peer review is the process where other experts in the same field evaluate a scientist's work before it is published in a journal. This ensures the research meets high standards of quality and validity.

Quantitative data refers to numerical measurements that can be counted or measured. "There are 3 tulips" gives a specific numerical count. The other options describe qualitative observations (smell, appearance, color) rather than measurable quantities.

Science is built on the assumption of naturalism and uniformity, meaning the laws of nature are consistent and do not change unpredictably. It avoids supernatural explanations and focuses on the natural world.

Nonrenewable resources exist in finite amounts and cannot be replaced on a human timescale. Natural gas is a fossil fuel that takes millions of years to form, unlike sunlight, wind, or geothermal energy which are renewable.

An environmentalist is a person who advocates for the protection and preservation of the natural environment. This role is distinct from a scientist, who conducts research, or a peer reviewer, who evaluates scientific work.

The environment encompasses all living and non-living things that surround an organism. This includes natural features like forests, human-made structures like buildings, and other people.