RNR 2039 WEEK 6 CHANG EXAM
PREPARATION LECTURE1-6 | 2025/2026
LATEST UPDATE | VERIFIED QUESTION
AND ACTUAL ANSWERS | 100% GRADED
Symbiosis - answers a close and long-term interaction between two species in an
ecosystem. Types of symbiosis include mutualism, commensalism, and parasitism.
Mutualism - answers symbiotic relationship in which both species benefit from the
relationship
commensalism - answers A relationship between two organisms in which one organism
benefits and the other is unaffected
parasitism - answers A relationship between two organisms of different species where
one benefits and the other is harmed
competition - answers can occur within or between species in an ecosystem where
there are limited resources.
-resource partitioning
resource partitioning - answers using resources in different ways, places, or at different
times- can reduce the negative impact of competition or survival
Biome - answers contains characteristic communities of plants and animals that result
from, and are adapted to, its climate
Major terrestrial biomes - answers taiga, temperate rainforests, temperate seasonal
forests, tropical rainforests, shrubland, temperate grassland, savanna, desert, and
tundra
global distribution of non mineral terrestrial resources - answers (ex: water and trees for
lumber)
varies because of some combination of climate, geography, latitude and altitude,
nutrient availability, and soil
worldwide distribution of biomes - answers [distribution of biomes is dynamic]
the distribution has changed in the past and may again shift as a result of global climate
changes.
,Freshwater biomes - answers streams, rivers, ponds, and lakes. These freshwater
biomes are a vital resource for drinking water.
Marine biomes - answers include oceans, coral reefs, marshland, and estuaries. Algae
in marine biomes supply a large portion of the Earth's oxygen, and also take in carbon
dioxide from the atmosphere.
The global distribution of nonmineral marine natural resources - answers [different types
of fish]
varies because of some combination of salinity, depth, turbidity, nutrient availability, and
temperature.
Carbon cycle - answers -movement of atoms and molecules containing the element
carbon between sources and sinks.
-Some of the reservoirs in which carbon compounds occur in the carbon cycle hold
those compounds for long periods of time, while some hold them for relatively short
periods of time.
-Carbon cycles between photosynthesis and cellular respiration in living things.
-Plant and animal decomposition have led to the storage of carbon over millions of
years. The burning of fossil fuels quickly moves that stored carbon into atmospheric
carbon, in the form of carbon dioxide.
Carbon sinks/reservoirs - answers Anything that absorbs more carbon than it releases;
examples: rocks, forests, soils, oceans and the atmosphere
largest carbon sink = rocks (limestone is calcium carbonate)
Nitrogen cycle - answers -the movement of atoms and molecules containing the
element nitrogen between sources and sinks.
-Most of the reservoirs in which nitrogen compounds occur in the nitrogen cycle hold
those compounds for relatively short periods of time.
-Nitrogen fixation is the process in which atmospheric nitrogen is converted into a form
of nitrogen (primarily ammonia) that is available for uptake by plants and that can be
synthesized into plant tissue.
*The atmosphere is the major reservoir of nitrogen.*
Nitrogen fixation - answers atmospheric nitrogen is converted into a form of nitrogen
(primarily ammonia) that is available for uptake by plants and can be synthesized into
plant tissue
phosphorus cycle - answers -the movement of atoms and molecules containing the
element phosphorus between sources and sinks.
- There is no atmospheric component in the phosphorus cycle, and the limitations this
imposes on the return of phosphorus from the ocean to land make phosphorus naturally
scarce in aquatic and many terrestrial ecosystems.
,- In undisturbed ecosystems, phosphorus is the limiting factor in biological systems.
phosphorus reservoirs - answers sedimentary rocks of marine origin, the oceans, and
organisms
Water cycle - answers -powered by the sun, the movement of water in its various solid,
liquid, and gaseous phases between sources and sinks.
-The oceans are the primary reservoir of water at the Earth's surface, with ice caps and
groundwater acting as much smaller reservoirs.
Primary productivity - answers the rate at which solar energy (sunlight) is converted into
organic compounds via photosynthesis over a unit of time.
Gross primary productivity - answers the total rate of photosynthesis in a given area.
Net primary productivity - answers the rate of energy storage by photosynthesizers in a
given area, after subtracting the energy lost to respiration.
how to calculate
Gross primary productivity - Respiration
(how much energy created) - (energy used by plants)
How is productivity measured - answers measured in units of energy per unit area per
unit time (e.g., kcal/m2/yr)
Light absorption - answers -Most red light is absorbed in the upper 1m of water, -blue
light only penetrates deeper than 100m in the clearest water
This affects photosynthesis in aquatic ecosystems, whose photosynthesizers have
adapted mechanisms to address the lack of visible light
Trophic Levels - answers -All ecosystems depend on a continuous inflow of high-quality
energy in order to maintain their structure and function of transferring matter between
the environment and organisms via biogeochemical cycles.
-Biogeochemical cycles are essential for life and each cycle demonstrates the
conservation of matter.
-In terrestrial and near-surface marine communities, energy flows from the sun to
producers in the lowest trophic levels and then upward to higher trophic levels.
Energy Flow and the 10% rule - answers - The 10% rule approximates that in the
transfer of energy from one trophic level to the next, only about 10% of the energy is
passed on.
- The loss of energy that occurs when energy moves from lower to higher trophic levels
can be explained through the laws of thermodynamics.
Food chains and Food webs - answers -A food web is a model of an interlocking pattern
of food chains that depicts the flow of energy and nutrients in two or more food chains.
, -Positive and negative feedback loops can each play a role in food webs. When one
species is removed from or added to a specific food web, the rest of the food web can
be affected.
Nitrogen cycle steps - answers N2 (atmospheric nitrogen) *nitrogen fixation* → NH3
*Ammonification* → NH4+ (Ammonium) [viable by plants] *Nitrification*→ NO2- and
NO3- [most readily available] *Denitrification*→ N2
what causes nitrogen fixation - answers bacteria soil
lightning
legumes roots
Biodiversity - answers ecosystem that includes genetic, species, and habitat diversity
The more genetically diverse a population is - answers the better it can respond to
environmental stressors. Additionally, a population bottleneck can lead to a loss of
genetic diversity.
population bottleneck - answers a type of genetic drift in which population size is sharply
reduced due to some catastrophic event
Ecosystems that have a large number of species - answers more likely to recover from
disruptions
Loss of habitat leads to - answers a loss of specialist species, followed by a loss of
generalist species. It also leads to reduced numbers of species that have large territorial
requirements.
Species richness - answers the number of different species in a community
species evenness - answers the relative proportion of different species in a given area
Ecosystem servies - answers all the processes through which natural ecosystems help
sustain human life
-provisioning, regulating, cultural, and supporting.
provisioning services - answers Benefits of biodiversity that humans use, including
lumber, fur, meat, crops, water, and fiber
regulating services - answers the ways that ecosystems control important conditions
and processes, such as climate, the flow of water, and the absorption of pollutants
cultural services - answers the spiritual and recreational benefits that ecosystems
provide
PREPARATION LECTURE1-6 | 2025/2026
LATEST UPDATE | VERIFIED QUESTION
AND ACTUAL ANSWERS | 100% GRADED
Symbiosis - answers a close and long-term interaction between two species in an
ecosystem. Types of symbiosis include mutualism, commensalism, and parasitism.
Mutualism - answers symbiotic relationship in which both species benefit from the
relationship
commensalism - answers A relationship between two organisms in which one organism
benefits and the other is unaffected
parasitism - answers A relationship between two organisms of different species where
one benefits and the other is harmed
competition - answers can occur within or between species in an ecosystem where
there are limited resources.
-resource partitioning
resource partitioning - answers using resources in different ways, places, or at different
times- can reduce the negative impact of competition or survival
Biome - answers contains characteristic communities of plants and animals that result
from, and are adapted to, its climate
Major terrestrial biomes - answers taiga, temperate rainforests, temperate seasonal
forests, tropical rainforests, shrubland, temperate grassland, savanna, desert, and
tundra
global distribution of non mineral terrestrial resources - answers (ex: water and trees for
lumber)
varies because of some combination of climate, geography, latitude and altitude,
nutrient availability, and soil
worldwide distribution of biomes - answers [distribution of biomes is dynamic]
the distribution has changed in the past and may again shift as a result of global climate
changes.
,Freshwater biomes - answers streams, rivers, ponds, and lakes. These freshwater
biomes are a vital resource for drinking water.
Marine biomes - answers include oceans, coral reefs, marshland, and estuaries. Algae
in marine biomes supply a large portion of the Earth's oxygen, and also take in carbon
dioxide from the atmosphere.
The global distribution of nonmineral marine natural resources - answers [different types
of fish]
varies because of some combination of salinity, depth, turbidity, nutrient availability, and
temperature.
Carbon cycle - answers -movement of atoms and molecules containing the element
carbon between sources and sinks.
-Some of the reservoirs in which carbon compounds occur in the carbon cycle hold
those compounds for long periods of time, while some hold them for relatively short
periods of time.
-Carbon cycles between photosynthesis and cellular respiration in living things.
-Plant and animal decomposition have led to the storage of carbon over millions of
years. The burning of fossil fuels quickly moves that stored carbon into atmospheric
carbon, in the form of carbon dioxide.
Carbon sinks/reservoirs - answers Anything that absorbs more carbon than it releases;
examples: rocks, forests, soils, oceans and the atmosphere
largest carbon sink = rocks (limestone is calcium carbonate)
Nitrogen cycle - answers -the movement of atoms and molecules containing the
element nitrogen between sources and sinks.
-Most of the reservoirs in which nitrogen compounds occur in the nitrogen cycle hold
those compounds for relatively short periods of time.
-Nitrogen fixation is the process in which atmospheric nitrogen is converted into a form
of nitrogen (primarily ammonia) that is available for uptake by plants and that can be
synthesized into plant tissue.
*The atmosphere is the major reservoir of nitrogen.*
Nitrogen fixation - answers atmospheric nitrogen is converted into a form of nitrogen
(primarily ammonia) that is available for uptake by plants and can be synthesized into
plant tissue
phosphorus cycle - answers -the movement of atoms and molecules containing the
element phosphorus between sources and sinks.
- There is no atmospheric component in the phosphorus cycle, and the limitations this
imposes on the return of phosphorus from the ocean to land make phosphorus naturally
scarce in aquatic and many terrestrial ecosystems.
,- In undisturbed ecosystems, phosphorus is the limiting factor in biological systems.
phosphorus reservoirs - answers sedimentary rocks of marine origin, the oceans, and
organisms
Water cycle - answers -powered by the sun, the movement of water in its various solid,
liquid, and gaseous phases between sources and sinks.
-The oceans are the primary reservoir of water at the Earth's surface, with ice caps and
groundwater acting as much smaller reservoirs.
Primary productivity - answers the rate at which solar energy (sunlight) is converted into
organic compounds via photosynthesis over a unit of time.
Gross primary productivity - answers the total rate of photosynthesis in a given area.
Net primary productivity - answers the rate of energy storage by photosynthesizers in a
given area, after subtracting the energy lost to respiration.
how to calculate
Gross primary productivity - Respiration
(how much energy created) - (energy used by plants)
How is productivity measured - answers measured in units of energy per unit area per
unit time (e.g., kcal/m2/yr)
Light absorption - answers -Most red light is absorbed in the upper 1m of water, -blue
light only penetrates deeper than 100m in the clearest water
This affects photosynthesis in aquatic ecosystems, whose photosynthesizers have
adapted mechanisms to address the lack of visible light
Trophic Levels - answers -All ecosystems depend on a continuous inflow of high-quality
energy in order to maintain their structure and function of transferring matter between
the environment and organisms via biogeochemical cycles.
-Biogeochemical cycles are essential for life and each cycle demonstrates the
conservation of matter.
-In terrestrial and near-surface marine communities, energy flows from the sun to
producers in the lowest trophic levels and then upward to higher trophic levels.
Energy Flow and the 10% rule - answers - The 10% rule approximates that in the
transfer of energy from one trophic level to the next, only about 10% of the energy is
passed on.
- The loss of energy that occurs when energy moves from lower to higher trophic levels
can be explained through the laws of thermodynamics.
Food chains and Food webs - answers -A food web is a model of an interlocking pattern
of food chains that depicts the flow of energy and nutrients in two or more food chains.
, -Positive and negative feedback loops can each play a role in food webs. When one
species is removed from or added to a specific food web, the rest of the food web can
be affected.
Nitrogen cycle steps - answers N2 (atmospheric nitrogen) *nitrogen fixation* → NH3
*Ammonification* → NH4+ (Ammonium) [viable by plants] *Nitrification*→ NO2- and
NO3- [most readily available] *Denitrification*→ N2
what causes nitrogen fixation - answers bacteria soil
lightning
legumes roots
Biodiversity - answers ecosystem that includes genetic, species, and habitat diversity
The more genetically diverse a population is - answers the better it can respond to
environmental stressors. Additionally, a population bottleneck can lead to a loss of
genetic diversity.
population bottleneck - answers a type of genetic drift in which population size is sharply
reduced due to some catastrophic event
Ecosystems that have a large number of species - answers more likely to recover from
disruptions
Loss of habitat leads to - answers a loss of specialist species, followed by a loss of
generalist species. It also leads to reduced numbers of species that have large territorial
requirements.
Species richness - answers the number of different species in a community
species evenness - answers the relative proportion of different species in a given area
Ecosystem servies - answers all the processes through which natural ecosystems help
sustain human life
-provisioning, regulating, cultural, and supporting.
provisioning services - answers Benefits of biodiversity that humans use, including
lumber, fur, meat, crops, water, and fiber
regulating services - answers the ways that ecosystems control important conditions
and processes, such as climate, the flow of water, and the absorption of pollutants
cultural services - answers the spiritual and recreational benefits that ecosystems
provide
