Science 10AP: Nutrient Cycles in...
Transcript of Science 10AP: Nutrient Cycles in...
Science 10AP: Nutrient Cycles in Ecosystems
2.2E Nutrient Cycles in EcosystemsName:
Date:
(Refer to p. 68 – 91 of BC Science 10)
Nutrient Cycling in the Biosphere
Make some notes differentiating nutrients, stores and nutrient cycles.
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Metric measurement units used in the diagrams of nutrient cycles:
· gigatonne: _______________________________
· megatonne: ______________________________
**Complete Act. 2-2A Understanding Nutrient Cycles
The Effect of Human Activities on Nutrient Cycles
Make some notes the effect of human activities on nutrient cycles.
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What was Biosphere II?
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Energy Flow and Chemical Cycling through Ecosystems
(not in text book)
Energy flow occurs linearly, in one direction, through ecosystems. Energy enters from ______________ and exits as heat loss.
Most of the energy acquired by a given level of the food chain is used for respiration at that level and escapes in to the surrounding environment as ______________________________________. This energy is therefore unavailable to the next level of the food chain.
Label the diagram below to differentiate between chemicals cycling through a system and energy flowing.
The Carbon, Nitrogen, and Phosphorus Cycles
Which five elements limit life in ecosystems? ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
Which of the five chemical elements are cycled between living organisms and the atmosphere?
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How does phosphorus enter the environment?
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Health of the ecosystem depends on a ______________________ of these five nutrients.
THE CARBON CYCLE.
· Every living thing contains ______________.
· Only _________% of the Earth’s crust is carbon.
How carbon is stored
Short term:
· ___________________________________________
· ____________________________________________
· ____________________________________________
· ____________________________________________
· ____________________________________________
Long term:
· ___________________________________________
· ____________________________________________
· ____________________________________________
· ____________________________________________
Define the following:
· sedimentation:
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· carbonate: __________________________________________________________
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Refer to THE CARBON CYCLE on p. 8 of your Data Booklet to answer the following.
1. The greatest carbon stores on earth: ___________________________________________________________________
2. The store that contains the least amount of carbon: ___________________________________________________________________
3. The greatest carbon exchange (in gigatonnes) and what is responsible : ___________________________________________________________________
4. The smallest carbon exchange (in gigatonnes) and what is responsible : ___________________________________________________________________
5. What process only releases carbon into the cycle? ___________________________________________________________________
How carbon is cycled through the ecosystem
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Photosynthesis
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The balanced chemical equation for photosynthesis is:
· Also occurs in some micro-organisms, such as _____________________________.
· Makes usable energy for __________________________.
· By eating plants, ___________________ obtain energy and take _______________ into their cells.
Cellular Respiration
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The balanced chemical reaction for cellular respiration is:
Create a diagram that illustrates the link between these two reactions.
Decomposition
The importance of decomposition in the carbon cycle: _____________________________________________________________________________________________________________________________________________________________________________________________________________________
Other ways carbon is cycled through ecosystems
· The following also play an important part in the carbon cycle, by releasing CO2 into the atmosphere:
· the oceans:__________________________________________________
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· volcanic activity:_____________________________________________
· decomposing trees: ___________________________________________
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· forest fires: _________________________________________________
HUMAN ACTIVITIES AND THE CARBON CYCLE
· Human activities have affected the natural carbon cycle in the following ways:
· Burning fossil fuels:
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· Land clearing/logging:
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The Nitrogen Cycle
Which macromolecules is nitrogen an important component of? ___________________________________________________________________________________________________________________________________________________________________________________________________
I. Proteins are made up of ________________ acids.
II. DNA is the abbreviation for _____________________________________
DNA is made up of many nucleotides.
View the Nitrogen cycle animation. It is very good.
http://www.mhhe.com/biosci/genbio/tlw3/eBridge/Chp29/animations/ch29/1_nitrogen_cycle.swf
How nitrogen is stored (textbook)
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How nitrogen is cycled through ecosystems
· ______% of the Earth’s atmosphere is nitrogen gas.
· Most organisms cannot use it in this form, so much of the nitrogen cycle involves ______ processes to make nitrogen available to plants, and then in turn to animals.
1. ________________________________________
2. ________________________________________
3. ________________________________________
1. Nitrogen Fixation: ________________________________________________
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Can occur in 3 ways:
1. In the atmosphere: _____________________________________
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· Compounds formed by _______ and _______ can enter soil through _______________________.
· Only small amounts
2. In the soil: ____________________________________________
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· Bacteria grow in root nodules and legumes.
· Symbiosis -> mutualism: plants get ____________, bacterial get _____________.
3. In water bodies: _______________________________________
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2. Nitrification: ___________________________________________________________
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· There are 2 stages involving nitrifying bacteria:
1. __________________________________________________________
2. __________________________________________________________
3. Uptake: _______________________________________________________
· These nitrogen compounds compose plant ______________.
· Herbivores and omnivores then eat plants, and use nitrogen for _________& ________________ _______________.
How nitrogen is returned to the atmosphere
Denitrification: ______________________________________________
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· denitrifying bacteria converted _____________ (______) back to ___________________ (____).
· Should be a _________________ between the amount of fixed nitrogen and nitrogen returned to the atmosphere.
· N2 is also returned to the atmosphere as ammonia (NH3) through _________________________________________________________
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How nitrogen is removed from ecosystems
· Excess nitrogen dissolves in ___________, enters the _______________________, and washes into _________and ____________.
· The nitrogen compounds eventually become trapped in ____________________________________, and will not be released again until the rock is ________________________.
HUMAN ACTIVITIES AND THE NITROGEN CYCLE
· Due to human activities, the amount of nitrogen in the ecosystem has __________________ in the last 50 years.
1. _______________________________________ and _________________________________ releases nitrogen oxide (NO) and nitrogen dioxide (NO2).
· Burning also releases nitrogen compounds that increase _____ ______________________ in the form of nitric acid (HNO3).
2. ________________________ often use large amounts of nitrogen-containing ______________________.
· Excess nitrogen is washed away, or leached, into the waterways.
· leaching: _______________________________________________________________________________________________________________________________________________________________________________________
· This promotes huge growth in aquatic algae = eutrophication: _______________________________________________________________________________________________________________________________________________________________________________________
Refer to THE NITROGEN CYCLE on p. 11 of your Data Booklet.
1. What two processes take nitrogen from the atmosphere and where do they occur? ________________________________________________________________________________________________________________________________________
2. Locate the two stages of nitrification. Name organism(s) and ions involved in the process.
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3. What is involved in uptake? List the ion(s) involved. ________________________________________________________________________________________________________________________________________
4. Locate denitrification on the data table. Name organism(s) and ions involved in the process.
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5. Locate and name another natural process that adds nitrogen to the cycle. ____________________________________________________________________
6. Locate and name two human activities that add nitrogen to the cycle. ________________________________________________________________________________________________________________________________________
The Phosphorus Cycle
Phosphorus is essential for _______________________ in plants and animals
Phosphorus is a part of the molecule that carries _________ in living cells.
· ______: adensosine triphosphate
· a special nucleotide that acts as the ‘energy currency of the cell’. Study this diagram to see what we mean by that:
Here you can see how energy is released from the ATP molecule when it is hydrolyzed to ADP and phosphate:
How is phosphorous used in plants? ___________________________________________________________________________________________________________________________________________________________________________________________________
How is phosphorous used in animals? ___________________________________________________________________________________________________________________________________________________________________________________________________
How phosphorus is stored
· Phosphorus is not stored in the ________________________.
· it is trapped in _______________________ (PO43–, HPO42–, H2PO4–) found in __________ (Earth’s Crust) and __________________________ in the ocean.
Refer to THE PHOSPHORUS CYCLE on p. 9 of your Data Booklet.
1. List the five phosphorus sinks, in order, from largest to smallest? ____________________________________________________________________________________________________________________________________________________________________________________________________________
How phosphorus is cycled through ecosystems
Weathering: _____________________________________________________
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Differentiate chemical weathering and physical weathering:
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· Weathering doesn’t occur until there is geological uplift.
· Geological uplift: __________________________________
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Refer to THE PHOSPHORUS CYCLE on p. 9 of your Data Booklet.
1. List the eight processes, in order, from largest to smallest involved in the flow of phosphorus in the phosphorus cycle? ____________________________________________________________________________________________________________________________________________________________________________________________________________
HUMAN ACTIVITIES AND THE PHOSPHORUS CYCLE
Human activities can either add excess phosphorus to the ecosystem or reduce the phosphorus supplies in the ecosystem.
· Add excess phosphorus:
· Mined for commercial fertilizers and detergents
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· Reduce phosphorus supplies:
· Slash-and-burn practices
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HOW CHANGES IN NUTRIENT CYCLES AFFECT BIODIVERSITY
· Any significant changes to any of these nutrients (____, _____, ____, _____, and _____) can greatly impact the health and biodiversity in an ecosystem
1. Carbon: contributing to _______________________
· _______________ carbon in the atmosphere, slight temperature changes and changes in water level can all affect ecosystem biodiversity
· If one part of the ecosystem is affected/removed, it affects the rest of the food chain/food web.
2. Nitrogen: can seriously affect __________ biodiversity
· Some plants better adapted to ______________ nitrogen levels than others and therefore out complete the less tolerant species.
3. Phosphorus: can affect _______ _________
· _________________ phosphorus have reduced algae production in some lakes, which is an important food source for _________________.
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