Aquatic autotrophs require inorganic carbon. 8tr6arf/t/n uyd-jl1bz v ;i6In what forms is inorganic carbon present in fr1 z u ; i/r-6ylnb/tv6jt8adaquatic ecosystems?

  Which of the following correctly describes how energy is lost from esfar 3.)aenn4cosystems?

  What is the name of the process that convertb +ft,cul7sab f68du41 ohoz1s carbon dioxide in the air to carbo1cl7 b4zf61 8satuob+d,fou h hydrates?

  Which of the following statements are correct ,h +2c.x. x(hlu3 avhak-urkf descriptions of food chains?

The diagram below shows a simplified scheme of the movement of carbon in1fni314a yy9njoiw 5e the ocean e5in jiayo3 1n4fwy91.

Identify the processes marked I and II.

  The illustration shows a6 /o1g*1lx da-nhuvp h, ap9gi rice cultivation system that eliminates the need for fertilizers, herbicides and pesticides by raising ducks in rice paddies. Additionally, Azolla, an aquatic floating fern, is grown in these fie p9nh-gv1lgx6od 1puh* aia,/lds because they harbour blue-green algae that fixes $N_2$​. This system produces duck, fish and rice for human consumption.


What would be a possible food chain for the rice cultivation system shown in the image?

  There is continuous cycling of carbon from the atmos nnae8jrwvu,8y12r z4phere to other carbon sinks. Which is the main sourvw 1j,2aznunyre 8r84 ce of energy for the carbon cycle?

The food web below shows the feeding relationships in a soil3 vpq3cs)h.y 0,tzn6x dwl8 ma ecosystem.

Draw a food chain with five trophic levels.

  What units are typically used for pyramidi0 jgvi:dc:5zs of energy?

  The image below shows an Arctic food web.qluds*:r(t ) )isw sl5

Which of the following organisms is not a heterotroph?

  Which of the following processes in the Carbon cycle requires the longest;jwmz(wd2c,xbvnsgk 0w, 15 m time?

  Which of the following statements 6 q)79gztckxh8wzy y0 are true?
I. Living organisms release energy from organic compounds and convert it to heat during the process of respiration.
II. Since heat cannot be transformed into other forms of energy it is lost from ecosystems.
III. Light energy from the Sun is converted to chemical energy by producers and then converted to heat during respiration.

  Which of the following diagrams shows the flow of energy in an ecosystem haae w 73xtxzq-9 al+6b7kx3qpd-ye 7awving four trophic levels? The size of ea-tqzl3y79 7x pqbd7a wee-x a6xw+ak3ch level represents energy values (in $kJm^{−2}yr^{−1}$) in the energy pyramids below.

  The figure below showqvn,b9dk30 doi9 +tufs the flow of energy per area per year in an ecosystem.

Aproximately what percentage of energy from the producers reaches the tertiary consumers?

  Which of the organisms in x-ex4)0vma+ ly g9ij ceq,3ml the food web below is both a secondary and a tertiary cximlaq3ylgm,c-)x 9+40jve eonsumer?

  Which of the following statements about b- prf pbie43 s2n71czgreenhouse gases is NOT true?

  Nutrients are constantly cycled in ecosystems, includin kk+hrl-)qt9og in the atmosphere as a gaseous form. Which of the following elements is ko-k )ht qr9l+not found in the atmosphere?

  A student set up an aquatic mesocosm using a commercially available seawatwzqdk9b;iw :yae f:j7+, abj91 hcpc2er-filled glass orb, which included algae, shrimp, som;zwe:,: j 7qbj29pkba +d1f whciacy 9e corals and gravel. The student placed it near a window to provide a light source. Which of the following statements are true?
I. The algae are autotrophs, produce carbon compounds and provide oxygen for organisms in the mesocosm
II. Saprotrophs present in the water and gravel help to recycle nutrients found in dead organisms
III. Herbivores usually present in a natural ecosystem can be excluded in the mesocosm

  Which of the following statements 1hxyn)i** 3k981 ejaijbwwsgis an incorrect description of energy flow in terrestrial ecos3xwewy* hi1 a)isn8 *1j 9gbjkystems?

The following diagram shows a tisc wgrc,:8enp0 )n8 crophic level pyramid of energy.

1.Label the bottom (step A) and topmost steps (step D) of the pyramid to describe what types of organisms are present in the two levels.
2.State which trophic level can support the largest population of people, step A or step B?
3.Explain why animals at level D are most vulnerable to becoming extinct.

  

The diagram above shows a simplified diagram of the movement of carbon in the ocean. Which of the following rows correctly identifies processes involved in the carbon cycle?

The following image shows th 3j-/pg if1fp*kdxf x(i sm14re productivity of a small terrestrial ecosystem with the numbers showing the f fx/-ikdsj4 *( if1fxm3p 1prglow of energy(kJm$^{-2}$yr$^{-1}$)

Net production = Gross production – energy lost to respiration
1.Outline how light energy is sequentially transformed into other forms of energy in the terrestrial ecosystem shown in the image.
2.Calculate the percentage of energy captured by the producers that is available to the secondary consumers in the ecosystem shown above.

  
What kind of fuels can be formed in conditions such as those shown in the picture above? The soil is anaerobic, acidic and waterlogged.

  Corals, oysters and sea urchins mec5o (- nn 5wxa0c8xhuse calcium carbonate to build their shells. Which of ox5 m0w(n-xen5 a ch8cthe following is NOT a source of carbon for these ocean-dwelling organisms?

  The figure below shows the flow of energy per unit area per year in vct 16/ktwe )darbitrary units. Gross production is the total kJ obtained through photosynthesis, and )dttwcv/1k e6net production is the kJ remaining after respiration.


What percentage of net production (kJ after respiration) is lost to decomposers by primary consumers?

  Which of the following statements describe a chemoa* ae ;w,*mx,kvwuqft1 utotroph?
I. Bacteria and extremophiles living in hostile environments like hydrothermal vents
II. Organisms which obtain their energy from oxidation reactions and form organic molecules primarily from carbon dioxide
III. Chemoautotrophs are dependent on the Sun for survival

  The following graph shows the concentration of atmospheric carbon dioxide meahv/j j4bd:nq +nn* kp15bajk;sured at Mauna Loa /djna*nk4vbj kpjb+h ;n15: qObservatory in Hawaii, USA.

Which of the following statements do not explain the rise and fall of the carbon dioxide levels shown in the graph above?

A student wants to set up an aquatice/en :k15kxbd4a 6i;hbbqs8j mesocosm using seawater to simulate conditions in the food web (shown in the image below) and tes nqieb65e841 jk :xha;bbd/ skt its stability. He used seawater and sand from the area to set up the system and added some small organisms to the mesocosm.

1.In the food web shown, identify an autotroph.
2.State a reason why phytoplankton shown in the food web would be a good addition to the mesocosm.
3.Discuss how saprotrophs perform a necessary function for the mesocosm.
4.Describe the disadvantages of using mesocosms in scientific investigations.

The following graphs show the concentran b,ww9 lkk*i if430iption of atmospheric carbon dioxide over time at Mauna Loa Observatory fik 0b3pi winwl49* ,kin Hawaii, United States.



1.Describe the overall trend in atmospheric carbon dioxide levels over time.
2.State one factor that has significantly contributed to increases in atmospheric carbon dioxide concentration as seen in the graphs.
3.Explain why the concentration of atmospheric carbon dioxide fluctuates annually.

  Which of the following statements ext s*y,k ;:tr zq4qfjh6plains the annual fluctuations of carbon dioxit*t4f ,6sr h:kj;yqqz de in the atmosphere?

The image below shows global sea c +dvgu p0lup7g0+*z zfl )r-llevels from the years 1880 to 2020.

1.There is a trend line showing changes in sea level from 1920 to 1960 and another trend line showing changes in sea level between 1980 and 2020. Describe the differences in sea level change between these two periods of time.
2.Outline the reasons for linking atmospheric carbon dioxide levels to the rise in sea levels.
Ecosystems growing in salt marshes are able to help reduce the effects of climate change by the sequestration (capture) of carbon. Sea level rise (SLR) has affected these ecosystems by flooding and eroding coastal areas.
The results from a recent study modelling the effects of a one-metre sea level rise on carbon sequestration by salt marshes in New York, United States, are shown in the graph below. The data shows the predicted effects by the year 2100.



3.Suggest an explanation for the difference in carbon sequestration between no SLR and one meter SLR, shown in the prediction graph.
4.Draw a diagram of the carbon cycle for a terrestrial ecosystem, and include carbon sinks, and processes associated with the cycle.

The diagram below shows the food web in a salt marshpqcua * f;el20, one of the most productive habitats on Eartupa2c fqe 0l;*h.


1.The numbers on the arrows show the percentage of gross primary production that flows into different trophic levels or is used in plant respiration.
2.Define gross and net primary production.
Identify the herbivores shown in the system.
3.If the energy available to consumers from producers in organic compounds is 300 g m$^{-2}$yr$^{-1}$(dry), calculate the amount of energy that is lost by export to the tide.1
4.(1)The table below shows the NPP for three trophic levels in a food web. Draw a pyramid of energy from the information in this table, labelling it appropriately with the trophic levels and corresponding NPP values (rounded to 3 significant figures as in the table).


(2)Outline a limitation of the ecological pyramid of energy.
5.Explain how a food web provides a more accurate representation of an ecosystem’s feeding relationships than a food chain.

1.Describe the process by wb 2.hxu-v/ci sf8fs1jhich detritivores and saprotrophs obtain nutrition.
2.Describe how a quadrat can be used to estimate the population of poppies in a field.
3.Energy and nutrients move through ecosystems differently. Describe how energy and nutrients move through terrestrial ecosystems.

A student wanted to study how food chains in leaf l2,iyg*x f2s cwj4o ;hjitter can be affected by the mass of initial leaf litter added. The student placed an increasing mass of leaf litter in three different tree holj why*f;o s4 2jc2xig,es and waited a few weeks. To collect data, the student collected all the leaf litter and placed it in an apparatus, as shown below. The heat from the light bulb dried out the litter from above and the heat and light drove the invertebrates through the wire mesh to the beaker below. The invertebrates were collected, the number of species counted, the species were identified and then they were put into their respective trophic groups.



1.(1)State the independent variable in the experiment.
(2)State the dependent variable in the experiment.
2.Suggest how the dry biomass of the leaf litter can be obtained.
3.Explain why using the dry biomass of leaf litter is advantageous to using the fresh biomass.


4.From the two graphs provided, describe the results of the experiment.

The image below shows a hydrothermal vent deep in the ocr2 bqw+2skr.h4iu j: zeans, where a diverse ecosystem is supported. A number of organisms thrive in these areas of high pressure anq ui2b+hrwj.4 :2zrksd darkness.


1.State an example of a chemoautotroph that is likely to be found in the hydrothermal vent shown above.
2.Compare and contrast photoautotrophs and chemoautotrophs.

1.Compare and contrast forests and marine phytoplanktov3/q20 pw2*4fshx vo 62cbtoxxn r:wen in their role in the carbon cy62/4x 2ho c*w2t xfe:3v wbxsvq n0rpocle.
2.Describe how aquatic autotrophs absorb carbon dioxide from the surroundings.

The image shows a food web in a sal y -pd/8fr1gw/ 1tqiqtt marsh ecosystem.


1.Identify all the detritivores in the food web shown above.
2.Define secondary productivity.
3.Explain why energy is lost during the transfer from producers to herbivores.
4.Describe a method a farmer could use to estimate the gross primary productivity per month of his wheat crop.

1.Draw and label a trophic pyramid of energy showin(.qxc meyb0, 6l5/s bu vngs0sg four levels.
2.Explain how the presence of a food web in an ecosystem makes it more stable than the presence of a single food chain.
3.The production and transfer efficiency of energy varies between ecosystems.
Describe how energy flows in and out of terrestrial ecosystems.

Dissolved $CO_2$
is increasing in standing waters of lakes and ponds. Research has shown this will impact the nutritional quality of phytoplankton (primary producers) and may further affect zooplankton (consumers) that feed on the phytoplankton.
Mesocosms were used to monitor three species of zooplankton, the water flea (Daphnia magna), the seed shrimp (Heterocypris incongruens) and the rotifer (Brachionus calyciflorus) under three different conditions of $CO_2$
in ponds and shallow lakes:
Treatment C - present day levels of $CO_2$, (control)
Treatment 1 - moderate increase of $CO_2$(possible future levels)
Treatment 2 - high increase of $CO_2$(more extreme future levels)
Glass jars filled with filtered pond water were injected with both carbon dioxide and air under pressure, and the representative species of zooplankton, water flea, seed shrimp or rotifer were added to the jars. They were monitored for survival, growth rate and body size over the next several days.
The image below shows the three species of zooplankton that were studied in the mesocosms.

The survival probability of the three species of zooplankton were monitored over several days in the mesocosms and the results are shown in the graphs below.


1.Giving a reason, predict which zooplankton is the least resilient to the effects of increased carbon dioxide.
2.Describe how using mesocosms for research is both an advantage and a disadvantage in predicting the effects of increasing carbon dioxide in the atmosphere.

1.Explain how limestone is made and descri +t 6wrdib01rybe the role it plays in the carbon cycl1 +r driwt0y6be.
2.Oil and natural gas are extracted to be used as fuels. Describe the formation of oil and natural gas.
3.Nutrients are cycled in all ecosystems. Draw and label the carbon cycle showing at least four stores or sinks and at least four flows or processes.

  The following image is a graph obtaine9a:yv-l,-zdbjqd o+bv7/ uoed by plotting values for net primary productivity (x-axis) abvd- yzjl -,/:bq9+ odeov7u and the biomass of herbivores (y-axis). The black dots represent one biome and the grey dots represent another biome.

The x-axis shows the increasing net primary productivity of biomes, and the y-axis shows the increasing biomass of herbivores. Which of the following choices correctly identifies the biomes represented in the graph above?

  The diagram illustrates the ca0whp af7j 9bl(hra- k3rbon cycle in a swamp. What is represented by the lettjh0pl-ra3a 9(hw 7bkf ers?

  The diagram shows the carbon stored in( (gm;acheivu6b.i):htc *y) ff-mmk some of Earth’s carbon reservoirs, and the estimated annua bg)mc)my;.cue*m hf(iitf( :av -kh6l carbon flux, in GT/yr, between reservoirs.

Which is a net flux between two reservoirs in the carbon cycle?