Ecosystems Overview Quiz

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Questions and Answers

What type of consumers are found at the third trophic level?

Herbivores

Detritivores

Producers

Carnivores (correct)

Which organisms are primarily responsible for decomposition in land ecosystems?

Herbivores

Plants

Bacteria and fungi (correct)

Carnivores

How much energy is typically transferred from one trophic level to the next?

20% to 30%

40% to 60%

80% to 95%

5% to 20% (correct)

What describes the more complex path of energy flow in ecosystems?

Food web Signup and view all the answers

Net primary productivity measures the total amount of energy fixed by which process?

Photosynthesis Signup and view all the answers

Which term refers to the total weight of all organisms in an ecosystem?

Biomass Signup and view all the answers

What happens to energy as it passes through different levels of the ecosystem?

It is lost at each trophic level. Signup and view all the answers

Herbivores are classified as which type of consumers?

Primary consumers Signup and view all the answers

What percentage of the sun's energy do plants typically convert into their biomass?

1% Signup and view all the answers

What is the primary reason for the limited number of top-level carnivores in an ecosystem?

The loss of energy at each trophic level limits support. Signup and view all the answers

Which of the following statements correctly describes the biomass of primary producers compared to higher trophic levels?

It is usually greater than that of higher trophic levels. Signup and view all the answers

How much of the original energy captured by photosynthesis is available to a tertiary consumer?

1/1,000th Signup and view all the answers

What term describes the process of physical components being reused within ecosystems?

Biogeochemical cycling Signup and view all the answers

In an ecosystem, which component has the greatest influence on the living portion?

Water Signup and view all the answers

Which cycle involves water evaporating from plant leaves via transpiration?

Organismic water cycle Signup and view all the answers

What is the main way water returns to the atmosphere in the environmental water cycle?

Evaporation Signup and view all the answers

What role do forests play in the water cycle?

They are the primary source of local rainfall through transpiration. Signup and view all the answers

What is the main issue associated with groundwater in the United States?

Chemical pollution is contributing to its deterioration. Signup and view all the answers

How is carbon primarily returned to the atmosphere?

From respiration and combustion. Signup and view all the answers

What happens to carbon when marine organisms die?

It is deposited as calcium carbonate, forming limestone. Signup and view all the answers

What is a consequence of deforestation on local climates?

Decreased humidity and lower chances of rainfall. Signup and view all the answers

What is one significant way that fossil fuels impact the carbon cycle?

They release carbon back into the atmosphere when burned. Signup and view all the answers

Why is the water cycle interrupted in areas where forests are removed?

Plant transpiration is decreased, reducing moisture in the atmosphere. Signup and view all the answers

Which of the following describes the process of combustion in relation to the carbon cycle?

It releases carbon stored in fossil fuels back to the atmosphere. Signup and view all the answers

What are the three zones in which organisms live in ponds and lakes?

Littoral, Limnetic, Profundal Signup and view all the answers

Which type of lake is characterized by abundant minerals and organic matter?

Eutrophic lake Signup and view all the answers

What process occurs when deeper waters in a lake rise to the surface in spring and fall?

Overturn Signup and view all the answers

Which characteristic is true of shallow waters?

They have the highest biodiversity of marine species. Signup and view all the answers

At what temperature is water most dense, causing it to sink?

4°C Signup and view all the answers

What are estuaries known for?

Being partly enclosed bodies of water with intermediate salinities Signup and view all the answers

Which statement accurately describes the open-sea surface?

It contains a high concentration of phytoplankton. Signup and view all the answers

Which zone of a lake is known as the shallow 'edge' where organisms often live?

Littoral zone Signup and view all the answers

What is a key characteristic of oligotrophic lakes?

Deep waters rich in oxygen Signup and view all the answers

What is a notable feature of deep-sea waters?

They contain few organisms but are diverse. Signup and view all the answers

How do some deep-sea inhabitants obtain energy?

From hydrothermal vent systems Signup and view all the answers

During thermal stratification, what happens to water that is cooler or warmer than 4°C?

It sinks below warmer water Signup and view all the answers

What typically occurs during the overturn process in lakes?

Deeper waters mix with surface waters Signup and view all the answers

What best describes freshwater ecosystems?

They include limited areas like lakes and ponds. Signup and view all the answers

What role do wetlands play in freshwater ecosystems?

They serve as a connection between freshwater and terrestrial ecosystems. Signup and view all the answers

What defines the primary factor of deep-sea organisms' adaptation?

Their bioluminescence for communication and predation Signup and view all the answers

What characteristic defines deciduous forests?

They drop their leaves in the winter. Signup and view all the answers

Which description best fits the taiga?

It features many species of coniferous trees. Signup and view all the answers

What is a primary feature of the tundra biome?

It contains permafrost typically within 1 meter of the surface. Signup and view all the answers

Which of the following accurately describes chaparral ecosystems?

They are characterized by evergreen, often spiny shrubs. Signup and view all the answers

What is a primary characteristic of polar ice caps?

They lie over both the Arctic Ocean and Antarctica. Signup and view all the answers

What type of vegetation is primarily found in the tundra?

Low-lying shrubs and grasses. Signup and view all the answers

In which type of climate do chaparral ecosystems primarily exist?

Mediterranean with dry summers. Signup and view all the answers

Which statement about deciduous forests is true?

They lose their leaves seasonally. Signup and view all the answers

Study Notes

Ecosystems

Ecosystems are the combination of a community and its habitat
A community is a collection of organisms living in a particular place
A habitat is the place where a community lives
Ecosystems are the most complex level of biological organization
Earth is a closed system regarding chemicals but an open system in terms of energy
Organisms in ecosystems regulate the capture and expenditure of energy and the cycling of chemicals
Producers are autotrophs (e.g., plants, algae, bacteria) that capture energy
Consumers are heterotrophs that obtain energy-storing molecules by consuming other organisms
Ecologists assign organisms to trophic levels, feeding levels based on the number of consumption stages away from the sun
Food energy passes through ecosystems from one trophic level to another
A food chain illustrates a simple linear progression of energy transfer
Food chains are composed of producers, consumers, and decomposers
Decomposers break down dead organisms

Trophic Levels

Producers occupy the lowest trophic level
Herbivores occupy the second trophic level, consuming producers
Carnivores occupy the third trophic level, consuming herbivores
Some carnivores eat producers and are labeled omnivores
Detritivores are special consumers that eat dead organisms
Decomposers break down organic matter
Bacteria and fungi are the main decomposers

Ecological Pyramids

There are generally more individuals at lower trophic levels than at higher levels
Plants fix about 1% of the sun's energy into their parts
Consumers process only about 10% of the energy available in the organisms they feed on
Biomass (total weight) of producers is usually greater than that of higher trophic levels
Food chains typically consist of only three or four steps, due to energy loss
A food web describes the complex, non-linear path of energy flow

Biogeochemical Cycles

Water cycles within ecosystems in two ways: -Environmental water cycle (water vapor condenses and falls as precipitation, evaporates into the atmosphere) -Organismic water cycle (water is absorbed by plant roots, evaporates from leaves via transpiration)
Deforestation disrupts the water cycle
In the US, more than 96% of fresh water is groundwater, occurring in aquifers
Carbon cycles between the atmosphere and living organisms -Plants trap carbon in organic molecules through photosynthesis -Carbon is returned to the atmosphere through respiration, combustion, and erosion
Respiration: Organisms release carbon dioxide
Combustion: Burn wood, fossil fuels, releases carbon
Erosion: Marine organisms die, create limestone, erosion releases carbon
The burning of fossil fuels releases stored carbon into the atmosphere

Nitrogen and Phosphorus Cycles

Most living organisms can't utilize nitrogen gas (N2) directly
Nitrogen fixation: Bacteria break triple bonds in N₂ and combine nitrogen with hydrogen, forming ammonia (NH₃)
Nitrogen fixation occurs in the absence of oxygen
The nitrogen-fixing bacteria are located in cysts that lack oxygen or in nodules found in plants, like beans
Farmers sometimes add fertilizers to supplement fixed nitrogen levels
Phosphorus is important soil nutrient in ATP and DNA
Most exists in soil and rock
Plants take up phosphorus from the soil or water, and when organisms die, phosphorus is recycled
Excess phosphorus in a lake leads to algal blooms, eutrophication, and reduced oxygen levels, decimating life

Latitude and Elevation

Temperature varies with elevation
At any given latitude, air temperature falls about 6°C for every 1,000-meter increase in elevation
When air rises against a mountain, it cools, releasing rain on the windward side
As air passes over a mountain and descends, its moisture-holding capacity increases, causing dryness on the leeward side (rain shadow)

Ocean Ecosystems

Oceans are typically cold and dark
Photosynthesis is largely limited to the top few hundred meters due to light penetration
Organisms in deeper waters rely on organic debris from the surface
There are three main types of ocean ecosystems: shallow water, open-sea surface, and deep-sea waters
Shallow water: Small area along the shoreline, high biodiversity, intertidal zones
Open-sea surface: Contains phytoplankton for photosynthesis, various fish species
Deep-sea waters: Few organisms, high diversity, bioluminescence

Freshwater Ecosystems

Freshwater ecosystems include lakes, ponds, rivers, and wetlands
Freshwater bodies are connected to land
Wetlands are intermediate habitats between terrestrial and aquatic biomes
A large amount of organic and inorganic matter enters freshwater bodies from nearby land environments
Ponds and lakes are divided into three zones: Littoral (shallow), Limnetic (open-water), Profundal (deep water)
Lakes are categorized as Oligotrophic (low organic matter, rich oxygen) or Eutrophic (high organic matter, low oxygen)
Temperature stratification and overturn processes impact nutrient availability

Land Ecosystems

A biome is a terrestrial ecosystem characterized by a specific climate and the organisms that thrive there
There are seven major types of biomes -Tropical rainforests: Diverse ecosystems -Savannas: Grasslands with trees, seasonal rainfall -Deserts: Dry areas with sparse vegetation -Grasslands: Temperate zones, often converted to agriculture -Deciduous forests: Lose leaves during winter -Taiga: Coniferous forests in North America and Asia -Tundra: Boggy grasslands in northern latitudes; permafrost present -Chaparral: Evergreen shrubs, dry summers -Polar Ice Caps: Arctic and Antarctic, minimal precipitation, scarce fresh water -Tropical Monsoon Forests: Slightly higher elevation, drier climates, seasonal rainfall from the ocean

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Description

Test your knowledge on ecosystems, including their structure and functioning. This quiz covers essential concepts such as producers, consumers, and trophic levels, as well as the flow of energy and cycling of chemicals within ecosystems. Perfect for students studying ecology or environmental science.