Biology Chapter 20: Ecosystems and the Biosphere

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Questions and Answers

What is the primary way groundwater is replenished in aquifers?

Percolation of water from rain and snow (correct)

Evaporation from lakes

Transpiration by plants

Surface runoff from rivers

Which of the following describes how streams receive their water?

They are maintained by surface water evaporation.

They flow due to groundwater inflow below. (correct)

They solely depend on melting snow.

They are filled by direct rainfall only.

What role does carbon play in living organisms?

It is a key component of fossil fuels.

It is primarily used for photosynthesis.

It forms the structure of organic molecules. (correct)

It is the main energy source for all plants.

What is a significant environmental concern regarding aquifers?

They are being depleted faster than they are replenished. Signup and view all the answers

Where does groundwater typically exist?

In the pores of sand and gravel or fissures in rocks Signup and view all the answers

Which nutrient cycles are primarily transported from land to water through runoff?

Minerals including carbon, nitrogen, phosphorus, and sulfur Signup and view all the answers

What has accelerated the use of fossil fuels since the 1800s?

The expansion of the industrial sector. Signup and view all the answers

How does water reenter the ocean in the water cycle?

Through evaporation from lakes and rivers Signup and view all the answers

What are the two major abiotic factors that determine the type of terrestrial biome in an area?

Temperature and precipitation Signup and view all the answers

Which characteristic is used to distinguish the eight major terrestrial biomes?

Temperatures and amount of precipitation Signup and view all the answers

Why are tropical rainforests often referred to as nature’s pharmacy?

They have potential for new drug discoveries from their biodiversity. Signup and view all the answers

What happens to the leaves of trees in tropical rainforests throughout the year?

They are evergreen and do not fall off. Signup and view all the answers

What is one of the main threats to tropical rainforests?

Logging and deforestation Signup and view all the answers

In terms of vegetation, how do tropical rainforests differ from deciduous forests?

Tropical rainforests have year-round foliage. Signup and view all the answers

Which of the following is NOT considered a biome?

Mountain ranges Signup and view all the answers

What is the primary reason fires are important in the management of temperate grasslands?

They suppress tree growth and maintain grasses. Signup and view all the answers

What type of climate can allow the same biome to occur in geographically distinct areas?

Similar climate conditions Signup and view all the answers

What type of vegetation dominates temperate forests?

Deciduous trees Signup and view all the answers

Which of the following biomes typically has less diversity of tree species?

Temperate forests Signup and view all the answers

How does the net primary productivity of temperate forests compare to that of tropical rainforests?

It is lower due to a dormant winter period. Signup and view all the answers

What effect do lightning strikes have on temperate grasslands?

They enhance the natural fire regime. Signup and view all the answers

What temperature range is typical for temperate forests?

–30°C to 30°C Signup and view all the answers

What role does leaf litter play in temperate forests?

It enriches the soil with nutrients. Signup and view all the answers

What happens to vegetation when fire is suppressed in temperate grasslands?

It converts to scrub or dense forests. Signup and view all the answers

What is the primary source of nutrition for corals in nutritionally poor waters?

Symbiotic relationship with protists Signup and view all the answers

What adaptation do corals living in deeper and colder waters have for obtaining energy?

Feeding on zooplankton directly Signup and view all the answers

Which category of fish primarily consumes plant material in coral reefs?

Herbivores Signup and view all the answers

What is the main threat to coral reefs resulting from climate change?

Warm ocean surface temperatures Signup and view all the answers

What phenomenon occurs as a result of corals expelling their protist partners?

Coral bleaching Signup and view all the answers

How long does it typically take to build a coral reef?

Thousands of years Signup and view all the answers

What role do predators play in coral reef ecosystems?

They hunt herbivores and maintain balance. Signup and view all the answers

What phylum do coral organisms belong to?

Cnidaria Signup and view all the answers

What characteristic do lakes in closed drainage basins have with respect to salt content?

They can contain extremely high salt concentrations. Signup and view all the answers

Which of the following is NOT a marine biome mentioned?

Freshwater rivers Signup and view all the answers

What is the primary distinction of the pelagic zone in the ocean?

It encompasses all of the ocean's open water. Signup and view all the answers

The aphotic zone of the ocean is defined as the region that lacks sufficient light for what process?

Photosynthesis Signup and view all the answers

Which of the following is true about the intertidal zone?

It experiences variation due to tidal cycles. Signup and view all the answers

What defines the photic zone in the ocean?

It is where photosynthesis can occur. Signup and view all the answers

What is the maximum depth of the Challenger Deep?

11,000 meters Signup and view all the answers

Which statement about ocean depth and light penetration is correct?

The majority of the ocean is aphotic due to lack of light. Signup and view all the answers

What is the average oceanic residence time for a phosphate ion?

20,000 to 100,000 years Signup and view all the answers

Which of the following processes contributes to the increase of phosphorus in ocean waters?

Weathering of rocks Signup and view all the answers

What is the primary consequence of excess phosphorus and nitrogen in aquatic ecosystems?

Eutrophication and formation of dead zones Signup and view all the answers

What is a dead zone?

An area with reduced levels of dissolved oxygen Signup and view all the answers

What role does phosphate play in terrestrial food webs?

It becomes available through weathering processes. Signup and view all the answers

What human activity is primarily responsible for the increase in dead zones?

Fertilizer runoff Signup and view all the answers

Which area has one of the largest dead zones, as mentioned?

Gulf of Mexico Signup and view all the answers

Which effect does the decay of excessive algae have on aquatic organisms?

Depletes dissolved oxygen in the water Signup and view all the answers

What are the three broad categories of ecosystems based on their general environment?

Freshwater, marine, and terrestrial Signup and view all the answers

Which resource is typically NOT needed by organisms in an ecosystem for competition?

Energy drinks Signup and view all the answers

In which ecosystem type do plankton and krill primarily thrive?

Deep ocean water ecosystems Signup and view all the answers

Which factor does NOT influence community dynamics within an ecosystem?

Soil color Signup and view all the answers

What percentage of Earth's surface is covered by freshwater ecosystems?

1.8% Signup and view all the answers

Which of the following statements about marine ecosystems is true?

Marine ecosystems consist of shallow ocean, deep ocean water, and deep ocean bottom. Signup and view all the answers

What constitutes a significant portion of photosynthesis on Earth, particularly in marine environments?

Phytoplankton Signup and view all the answers

Which type of ecosystem is known for being the least diverse?

Deep ocean bottom ecosystems Signup and view all the answers

What is the primary vegetation type in chaparral regions?

Shrubs Signup and view all the answers

Which characteristic is crucial for the regeneration of plants in chaparral after a fire?

Ashes rich in nutrients Signup and view all the answers

What is a key factor limiting tree growth in temperate grasslands?

Frequent fires Signup and view all the answers

In which regions are temperate grasslands predominantly found?

Central North America and Eurasia Signup and view all the answers

What annual precipitation range does the chaparral biome typically experience?

65 cm to 75 cm Signup and view all the answers

What adaptations do chaparral plants exhibit?

They are dormant during summer droughts. Signup and view all the answers

What is a significant consequence of the dense root systems in temperate grasslands?

Reduction of soil erosion Signup and view all the answers

Which of the following biomes is primarily characterized by a treeless landscape?

Temperate grasslands Signup and view all the answers

What abiotic factor primarily affects productivity through photosynthesis in aquatic biomes?

Light availability Signup and view all the answers

How does water temperature impact aquatic organisms?

It affects growth rates and oxygen availability. Signup and view all the answers

Which characteristic distinguishes freshwater biomes from marine biomes?

Significantly lower salt content Signup and view all the answers

What type of environment is characterized by varying salt levels between freshwater and marine systems?

Brackish water environments Signup and view all the answers

What role do currents and tides play in marine biomes?

Affecting nutrient distribution and habitat replenishment Signup and view all the answers

Which abiotic factor has a consistent influence on organisms in rivers?

Constant water movement Signup and view all the answers

Which of the following statements is true regarding the composition of aquatic communities?

Abiotic factors shape the diversity of both freshwater and marine communities. Signup and view all the answers

What happens to light penetration as one moves deeper into a body of water?

Light diminishes until it cannot reach certain depths. Signup and view all the answers

What is the correct sequence of processes involved in the nitrogen cycle?

Ammonification, Nitrification, Denitrification Signup and view all the answers

Which of the following statements about nitrogen fixation is true?

It converts nitrogen gas into ammonium. Signup and view all the answers

Which bacteria are primarily responsible for converting nitrates back into nitrogen gas during denitrification?

Pseudomonas and Clostridium Signup and view all the answers

What is an effect of human activities on the nitrogen cycle?

Release of nitrogen oxides into the atmosphere Signup and view all the answers

What is the main product of ammonification in the nitrogen cycle?

Ammonium (NH4+) Signup and view all the answers

Which process follows ammonification in the nitrogen cycle?

Nitrification Signup and view all the answers

What is a potential environmental consequence of nitrogen released from artificial fertilizers?

Eutrophication of water bodies Signup and view all the answers

Which of the following processes is incorrectly matched with its function?

Denitrification - Converts nitrites to nitrates Signup and view all the answers

What is primarily responsible for the clear water observed in headwater streams?

Minimal silt levels Signup and view all the answers

How does tree cover affect photosynthesis in headwater streams?

It reduces photosynthesis by creating shade. Signup and view all the answers

What adaptation do some species of mayflies have for surviving in fast-moving water?

Flattened bodies with modified claws Signup and view all the answers

What happens to the width of the river channel as it flows away from the source?

The width gradually widens. Signup and view all the answers

Which of the following statements is true regarding sediment in rivers?

Slower flow rates allow silt to settle and deposit. Signup and view all the answers

What nutrient input is vital for the ecosystem of headwater streams?

Decomposing leaves and organic material Signup and view all the answers

How does the temperature of river water typically change as it flows farther from the source?

It increases due to longer sunlight exposure. Signup and view all the answers

What role do freshwater trout play in headwater streams?

They serve as an important predator. Signup and view all the answers

Which of the following statements accurately describes the abyssal zone?

It has very high pressure and low oxygen content. Signup and view all the answers

What is the primary energy source for chemosynthetic bacteria in the deep ocean?

Hydrogen sulfide Signup and view all the answers

Where are coral reefs primarily located?

In warm shallow waters within the photic zone Signup and view all the answers

Which of the following organisms are NOT typically found in the abyssal zone?

Photosynthetic corals Signup and view all the answers

Which zone of the ocean has sufficient light for photosynthesis?

Photic zone Signup and view all the answers

Which is a defining feature of coral reefs?

They depend on mutualistic relationships with protists. Signup and view all the answers

What is a common misconception regarding the environmental conditions of the abyssal zone?

It can sustain photosynthetic organisms. Signup and view all the answers

What type of relationship do corals in shallower waters have with their protist partners?

Mutualistic Signup and view all the answers

Study Notes

Chapter 20: Ecosystems and the Biosphere

Ecosystem ecology builds on organismal, population, and community ecology
Ecosystem includes all biotic (living) and abiotic (non-living) components
Abiotic components: air, water, soil, climate
Ecosystem biologists study nutrient and energy flow between organisms and environment
Key examples: Karner blue butterfly and wild lupine (Figure 20.1) in an oak-pine barren habitat
Characteristic features include fire and nutrient-poor soil, low in nitrogen

20.1 Water's Energy Flow Through Ecosystems

Ecosystems vary in size (from tide pools to rainforests)
Differentiate between food chains and food webs
Food chains: linear sequences of who eats whom, with a single path
Food webs: interconnected feeding relationships where organisms interact in complex ways, indicating energy flow and transfer
Efficiency of energy transfer affects ecosystems (energy decreases at each trophic level)

20.2 Biogeochemical Cycles

Energy flows directionally, matter is recycled in ecosystems
Six most common elements: carbon, nitrogen, hydrogen, oxygen, phosphorus, sulfur
Biogeochemical cycles involve movement through living things and environment
Includes processes such as weathering, erosion, and subduction
Water cycle: Water moves and stores in the atmosphere, oceans, groundwater, and ice.
Important processes: evaporation, sublimation, condensation, precipitation, subsurface water flow, surface runoff
Water (essential), moves through biosphere and ecosystem (inorganic compounds)

20.3 Terrestrial Biomes

Biomes: Large-scale communities distinguished by dominant plant types
Biomes determined by temperature and rainfall
Include: tropical rainforest, savanna, desert, chaparral, temperate grassland, temperate forest, boreal forest, tundra.

20.4 Aquatic and Marine Biomes

Aquatic biomes: influenced by abiotic factors (light, temperature, flow regime, dissolved solids)
Ocean zones: Intertidal, neritic, aphotic
Different aquatic zones: freshwater (lakes, ponds, rivers, streams, wetlands), marine (coastal areas-estuaries, intertidal zone, neritic zone, oceanic zone)
Importance of light, temperature, and water movement on aquatic organisms and communities
Characteristics of standing water (lakes, ponds) and flowing water (rivers, streams)
Importance of abiotic and biotic factors influencing communities
Key concept: Corals and reefs: importance of their role, location and effects

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Description

This quiz explores Chapter 20 focusing on ecosystems and the biosphere. It covers key concepts such as nutrient and energy flow, the distinction between food chains and food webs, and the role of abiotic factors. You'll also learn about important examples like the Karner blue butterfly and wild lupine in specific habitats.