What is the name of the process that converts carbon dioxide in the airos3fedi-ixu0h,5 c/ o to carbohydrax5 0efosid ,3/ hiuo-ctes?

The diagram below shows a simplified scheme of thell,z9w+ hby6 o movement of carbon in the oceohybl 9w,6z+ lan.

Identify the processes marked I and II.

  Rain forests are known to have tall trees and a lar s,37w5; qkvyuz 5epnhge biomass with high productivity, despite infertile soils. The growing conditions hav,s;ehnqw vp7 u5 z5y3ke been known to nurture the presence of many interdependent organisms. These species also interact with the physical environment they inhabit.

Which of the following is described here?

  There is continuous cycling of carbon from the atmosphere to other carbon w5 lx53ev( i hl+aicx/sinks. Which is the main source of energy for t5 ic eh5l+w3aliv/x(xhe carbon cycle?

  What are the effects of plastic pofy o)we)s 4i 6f1bfsn- e+;etrllution in marine waters?
I. When plastic enters marine waters, it breaks down into smaller pieces due to sunlight, wind and water action, eventually disappearing.
II. Sea turtles consume plastic because of its transparency and resemblance to jellyfish.
III. Plastic nets entrap fish, sea turtles and mammals.

  Nutrients are constantly cycled in ecosystems, incluh-)0vzl0a ;lkg 1dmhkding in the atmosphere as a gaseous form. Which of the following elements is-lza 1h;0ldk v) hg0km not found in the atmosphere?

  A student set up an aquatic mesocosm using a commercially available seawp0b vh+2 9blciz.xq: aater-filled glass orb, which included algae, shrimp, some corals and gravel. The student placed it near a window to provide a lx.2qbbaz+lc0 ihv 9p :ight 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

  
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?

  During a field day, students were asked to investigate the effect o bg3ek9ie5m ur,-l yv*b3c2 sff soil salinity on the distribution of plant species. Students designed an experiment that measured the number of plant species found up the shore at varying distances from the high tide line. Three groups of students investigated three sites on the same shore. The distance from the high tide line was taken as an indication of the salub,35vmc-3i k 9br ysge*2 felinity levels. The results are shown in the table.


1.1.Identify the independent variable.

1.2.Outline the steps students could take, and the equipment they could use, to collect their results.

2.1.Suggest a reason for the discrepancy in the number of species sampled in areas 1, 2, and 3.

2.2.Describe a way the students could reduce the impact of discrepancies on their collected data.

3.The different species of plants found in each area were recorded in a table.


Calculate how many times greater the number of plant species found in Area 1 was compared to Area 2.
The number is   .
4.Evaluate the students’ investigation into salinity's effect on plant species distribution.

  Ecological reserves in adjoining areasn; jbtje9ou* .0ltec y 9mq(m9 are connected by passageways or small strips of land to enabl( tm9om9 bnc09t; lj*eqjuye.e animals to cross between the regions. Which of the following would describe these connections?

  A student wants to set up r1ye7 +bjwso *ob7obf6i (; pnan aquatic mesocosm using seawater to simulate conditions in the food web (shown in the image below) and test it;rb*no1owby7b7p 6j f (o+si es 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.
It is   .
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.

1. A student had a small pond in the backyard and wanted to add some xvah3g-od7dqnyz j1nnl l89o ;dd) -8fish. The fish would be predators of the pond and feed on the zooplankton (prey) growing in the pond. Zooplankton are small floating or weakly swimming organisms that are dependq9dl;1d zdgvnl8x)jn o - d8h-3 nyao7ent on the phytoplankton or algae for their supply of nutrition.

She wanted to first determine whether Fish A or Fish B would be more suitable, or if both fish could be added to the pond. As a trial, she set up four mesocosms using water from the pond. She monitored the mesocosms and then added the fish to three of the mesocosms as shown. She took samples of water from the different mesocosms and tested it for chlorophyll content at a research lab nearby.


1.Outline why the mesocosms used would be considered a ‘closed system’.

2.Describe why adding mud or soil to the mesocosms would be advantageous.

3.Outline the reason for including ‘Mesocosm A’ with the experiment.

4.Explain the reason for monitoring chlorophyll content to analyze the effects of the fish as a predator.

5.State another variable that could be monitored to see the effect of adding fish to the mesocosms.

The following table shows the results obtained for chlorophyll (μg dm$^{-3}$) with the different additions of fish.

6.From the results obtained, suggest why the student decided to add both fish A and fish B to the pond.

1.Describe the proce/:kb),eokwrb . 93f x:rns-kytazu;tss by which 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.

1.Compare and contrast for1hb s k3oc+ 4rwxc/6grests and marine phytoplankton in their role in the carbongxrrh+k4b 3c1o/ w cs6 cycle.

2.Describe how aquatic autotrophs absorb carbon dioxide from the surroundings.

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 limestonek flb(, l/jbwqusu ru i63( t4y+aq15r is made and describe the role it plays in the carbon cyclq fl,r1(rij+b(ubtw u/yskul3a q5 46e.

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.

  Much of plastic pollution is non-biodegradable, which means it pee52*c tk3n jj)imfvd- rsists in the environment for long periods of time. Macroplasjefnj )-i*mvkt d325ctic pollution is defined as plastic debris that is larger than 1 mm and microplastic pollution less than 1mm.

On a field trip to a local beach in a temperate climate, students were asked to collect samples of sand and measure the number of pieces of plastic debris present. To do this, 5g samples of sand were collected and placed in a beaker. 50 ml of a concentrated salt solution was then added to the samples, which caused plastic debris to float to the surface. Plastic debris was removed from the samples, measured, and categorised, and the results were recorded in a table. The experiment was repeated in another school in a tropical climate, and the results were compiled.

1.1.Identify one controlled variable from the methodology.

1.2.Suggest the importance of having a standard classification for plastic debris in this investigation.

2.1.Calculate how many times greater the mean number of microplastic debris sampled was in the tropical climate compared to the temperate climate.
The number is   .
2.2.State which uncontrolled variable is most likely responsible for the higher numbers of microplastics sampled compared to macroplastics in the tropical climate. Give a reason for your answer.

3.Students in both climates noted the varying sand particle size of the sand samples taken at each beach.

3.1.Describe a limitation to the methodology based on this information.

3.2.Suggest a method to reduce the variability in particle size.

4.Evaluate the use of microplastic and macroplastic categories in this investigation.

  Hummingbirds are the chief pollinators for yb +.86gc*)4tajrg kny(kr qy a wide variety of flowering and fruit plants and are considered essential keystone.j )gn8y6gtrycb+ kqa k4y( *r species. Which of the following statements describe a keystone species?

I. The species, if removed, would drastically change the ecosystem
II. The species whose influence is out of proportion to its abundance or biomass
III. The keystone species is a dominant species, one that has a significant effect

  Which of the following factf wh mv4me(h7+ors do not affect the sustainability of agriculture in a short period ovwm 4f +7hem(hf time?

  Which of the following are the same for the processes of pr4tv ,nx nj)jqd:40.y t sfl*zpimary and secondary succ:t jd*pln qyv4ztn. s0xf,j)4ession?
I. The presence of pioneer species
II. A varying rate of succession
III. The starting point of succession

  Which of the following is a characteristic of a 2+p. k12mo-mf ftsg xmclimax community?

1.Logging trees from forests and fishing from marine waters ar 5,+jcl-qt( r uehig4re two forms of income derived from natural resources. Outline the factors that need to be addr ri-eq4h ,jg5(tr+lcu essed to make both forms of income sustainable.

2.Describe how choosing to consume locally grown foods can reduce the environmental impact of agriculture, making it more sustainable.

3.Discuss the causes and impacts of eutrophication on water bodies due to agricultural practices.

  Which of the following is an example of ecological succes5a- lriq36f yfsion?

1.Outline the primary sources of variation in a species.1yq meyr994.kw eif 2z

2.Describe the possible outcomes of a population producing more offspring than available resources can support.

3.John Endler carried out a series of experiments in the 1970s on the selection pressures that influenced the colour of guppy fish. State the independent variable in Endler’s experiments and explain the selective pressures exerted on male guppies.