What is the name of the proce4u fdge-e0yrn( g44swss that converts carbon dioxide in the air to carbohyd d0 w4(yg44r-usegnfe rates?

The diagram below shows a simplified scheme of*rvzv1*naef wtq9l ( 2 the movement of carbon in the oceantze vw9 lr n(a2fv*1q*.

Identify the processes marked I and II.

  Rain forests are known to have tall trees and a large biomass with higf+u;yl,5 ,gp 2k fh- d3-cou,cz uzikhh productivity, despite infertile soils. The growing conditions have been known to nurture the presence of many interde p;giu ou,hc,l- ykzzuh-,d3cf 5k+2f pendent 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 othebsqf ,vr52t6 4wskir)r carbon sinks. Which is the main5wr)s4rsk 2 ift ,vbq6 source of energy for the carbon cycle?

  What are the effects of plastic pollution in marine wateht) x) zb:1cxxa9, qv,um6x xirs?
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, includi vdxlkot )10 zrpq ue3i248x3ing in the atmosphere as a gaseous form. Which of the following elements is not found in the at q x3it8 1pok)2 vxuize40ldr3mosphere?

  A student set up an aquatic mesocosm os qhfo/w:-*a using a commercially available seawater-filled glass orb, which included algae, shrimp, so*os: hqaf w/-ome 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

  
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 investigatezt* f3lf,v.f5x f*xzg k3m. rorug ;5i;p vgr+ the effect of soil salinity on the distribution of plant species. Students designed an experiment that measured the number of plant species found up the zgr5rftxl+gmpg3, vor3vx ;; *z .iu5f.f k f*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 salinity 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 areas are connected by passageways or small stftxhip nto+h*0:x:t-rips of land to enable animals to cross between the regions. Which of the following would describe p :i0+xthn-o*t ftxh: these connections?

  A student wants to set adfo6 k/6k ,ogup an aquatic mesocosm using seawater to simulate conditions in the food web (shown in the image below) and test its stability. He used seawater and sand g 6fa/ok6o, dkfrom 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 adxb3 qbh3(pr;sf hf9 o(d some fish. The fish would be predators of the pond and feed on the zooplankton (prey) growing in the pond. Zooplankton bb(x3; hf s3pfrqoh(9are small floating or weakly swimming organisms that are dependent 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 process by which detritivores j6ea( js .6oejand 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 fd+;p q +ctbuf1z bfskn(.q3/zorests and marine phytoplankton in their role in the carbon cycs;zun. f qf +(q/pkd+b1bcz 3tle.

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 limestone is made and deyy6wjm.z)fe73 g7 rum scribe the role it plays in the carbon cycle. 73ew y7jz)fym6rmgu.

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 persists i 1 wg,*lsqaiv9n the environment for long periods of time. Macroplastic pollution is defined as plastic debris that is larger than 1 mm an*19q,sv gawild 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 *qs+5b)t ijd( pza. a blmw)5somqswr-6+2eh pollinators for a wide variety of flowering and fruit plants s+a* 6ztl) 5. 2wmr j s+hdow(ebq5ipqb-)mas and are considered essential keystone 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 factors do not affect the sustainability of agriculture uj3f/px)r q.q in a shf jx/q3qr .p)uort period of time?

  Which of the following are the same for the processes of primary avanl0t. 77ev tnd secondary succesv7.la0tn7 ve tsion?
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 climax coz m q)+clti0oqkjff20m0 3ov0 mmunity?

1.Logging trees from forests and fishing from mf/fnhmw;+ 1hccxu2r 3l6mta: arine waters are two forms of incom+un: fxrhm1 l;m6cthf2w3 c/ ae derived from natural resources. Outline the factors that need to be addressed 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 successyl.p1n(rgv;v 5 ds bx4ion?

1.Outline the primary sources of variation in a speci 3zrmgw1p. +jkes.

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.