What is the name of the process that converts carbon dioxido4* hq ms2 ypk.9ydgosk+6gg9e in the air to carboh9dy+.ggy94pkgm 2 q *o6kssho ydrates?

The diagram below shows a simplified scheme of the movement bxlm x uelqej+v*83 86of carbon in the oceanx8*l vje 6 x3e+u8bmql.

Identify the processes marked I and II.

  Rain forests are known to have tall trees and a large biomink9wdiz (py78b c3,wass with high productivity, despite infertile soils. The growing conditions have been known 78cby,w(k wd3npi 9zito 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 atmosp (1)3mkv7 eyk;bouivhhere to other carbon sinks. Which is the mvi1m7kyv; (keu3ho )bain source of energy for the carbon cycle?

  What are the effects of plhk2z7f)l ;qx 3 wswi1kastic pollution 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, inwzugairk5n9v 0ux1( 3 cluding in the atmosphere as a gaseous form. Which of the following elements is not fr 3xav95k(uwn0u iz1gound in the atmosphere?

  A student set up an aquatic mesocosm using a commercially ava6z1vq ku5v3dvilable seawater-filled glass orb, which included algae, shrimp, some corals and gravel. The student placed it near a winqzd3vvk6 1 5vudow 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 investigate the effect of soil ( kek(aug4*vp 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 salinity le* gvp(ae( kku4vels. 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 passageweu(d;1bgq ll.txb9 g/i sul(3 /njm d2ays or small strips of land to .lmg9jb /idtg ;3beu u/xsd(12(nqll enable animals to cross between the regions. Which of the following would describe these connections?

  A student wants to set up an aquatic mesocosm using seawater to siwsv:*7sjbnhl0*l 8 qhmulate conditions in the food web (shown in the image below) and tb80 **hslhlsv w7 njq:est 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.
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 so9 k7vqf ogve2y4ws2j q)wjayy8s5, 2rme fish. The fish would be predators of the pond and feed on the zooplankton (prey) growing in the pond. Zooplankton are2frv)2sojq9jyywa yw, q2s8 k7v54eg 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 and saprotrophs obtain n4 3 q- r5vufxvtftd9oxi 2u7+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 forests and mar*0z vhzz,oz bb*4nxb) ine phytoplankton in their role in the carb*zxb4zbz )* vozn,h0b on 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 limestone is ma( g)f5zfdpmhp cm+ r*,de and describe the role it plays in the carbon cycle. +p,5gzm f hcmrd *fp)(

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 9jr2 w qw.lpek4uvl+;3k 0sj npersists in the environment fo 4s3el9 0kq wp+2lrujkn.jwv;r long periods of time. Macroplastic 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 a wide variety of itft.bq0t9j8 flowering and fruit plants and are considered essential keystone species. Which of the following statements descriti 80jt tbq9.fbe 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 n,47( pg +m(vudafge hnot affect the sustainability of agriculture in a sho7(hpa(vedf,+mg 4gn urt period of time?

  Which of the following are the samen :zvt:( eam3o)a 7blu(dqxb1 for the processes of primary and secondary succev azul b d(b:na7e:)(1oq3mxtssion?
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 clmf*h-*,c1nb7zu jftr)1y d, oby q7amimax community?

1.Logging trees from forests and fishing from marine waters ar n3l5ks ax3cwu19 1bcbb :zol7e two forms of income derived from nas 1k:5nz913co37c b lbxlawubtural 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 succ 8q u8evja6pww(e5z3mession?

1.Outline the primary sources of variatio+ nvbnhv5 bmi348 +wiwn in a species.

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.