Crabs, earthworms, mites edt;zlj 4c-3.hx f)qr and snails feed on the remains of dead plants and anima r4;e) hz 3ft.lx-djcqls. What type of organisms are these?

  Which of the following f/5d)q.,phy eyg+ yo:n7ode ois not a saprotroph?

  Some fungi obtain nutrients by releasing y g* m7b55+f lprk.fbpdigestive enzymes into their surroundings. The enzymes break down things such as dead and decaying leaves and the fungi then absorb the products. Which of these terms best describes +m5. gpkp*lbr7ff b5ythese fungi?

  The illustration shows a rice cultivation systemawl*a g+by. 9zxc 772bcroe2v that eliminates the need for fertilizers, herbicides and pesticides by using ducks in the organic cultivation of rice. Inl2v7c c 9.ba gox+2bwarz*7ye addition, Azolla, an aquatic floating fern, is grown on these fields because it harbours blue-green algae which can fix atmospheric nitrogen. Using this system, rice, ducks, and fish can all be produced for human consumption in one location.

  Identify the row in thom8 ixk*hh9m,zq 94knl mi7hd/zhe0 q3,hph 2 e table which gives the correct information about the different types of organisms. 48 o,ih z 0 /z m99hk*hhmn p,2hkqq3eimd7lhx

  A student set up an aquatic mes5-rcka0pz ;lx ocosm using a commercially available seawater-filled glass orb, which included algae, shrimp, some corals and gravel. The student placed it near a window to provide a light source. Which of the followrx czl5-apk 0;ing 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 is/arb0l09rnk/ umces a o61e true for holozoic nutrition?
I. Demonstrated by saprotrophs
II. Involves complete or partial ingestion
III. Food is digested internally

  Which term refers to organisms that are bothzrke3ljk 8jh7k m9 1+q autotrophic and heterotrophic?

  What are incisors usediti9mk .6h;t 4 .vhl9arbcso 3 for?

The image below represents the skull of a gorill4f7wk7 7 -llofge0j0tulg/ cla, chimpanzee, and human.

1.1.Outline the roles of different types of teeth.

1.2.Gorillas are primarily herbivorous but have large canines. Suggest a reason why.

1.3.Compare and contrast the teeth of a carnivore with a herbivore.

2.In terms of diet, distinguish between a folivore and a frugivore.

  Chytrids are unicellular organisms that feed oxwj76bh 5sa* 1/ym lyxn pollen through extracellular secmxh17x laws5 /yb*jy 6retion of digestive enzymes and absorption of the breakdown products. Which statement describes the nutritional mode of this organism?

  Zooxanthellae are algae that live ixlws+t,wynf :,svvc4l(wclw q.b +; 0nside coral. Corals feed on the carbon compounds t(fw+0 cv l:+yqlxcw ;bw,nlv ws.,4sproduced by zooxanthellae from carbon dioxide, water, and sunlight. Which describes the nutrition of these organisms?

  A student wants to set up an aquafogha8r 89hi /tic mesocosm using seawater to simulate conditions in the food web (shown in the image below) and test its stability. He used seawater and sand from the area to set up the syste 9agfh 8/r8oihm and added some small organisms to the mesocosm.


1.In the food web shown, identify an autotroph ,which 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 fish. The)or* 8n9pqpfnmkooz 2nsz 7l490s3 sy fish would be predators of the pond and feed so0*n )937nz r ms pzfkq42 9yo8onslpon the zooplankton (prey) growing in the pond. Zooplankton are 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 sa2of1 pmq ./x:zbt1wwbprotrophs 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.Outline the differences between mixotrophic and holozoic , ,edna0-gzfhnutrition.

2.Describe how herbivores are adapted to eating plants.

3.Explain the differences between obligate anaerobes, facultative anaerobes and obligate aerobes.