Crabs, earthworms, mites and snails feed on the remains of dead pk5iy qri2i) *wikv l+;lants and animals. Whkriw2q* 5 ;i)iy +likvat type of organisms are these?

  Which of the following i(acz 2i0xdlffp)j7 0ccw 4x2xs not a saprotroph?

  Some fungi obtain nutrients by releasing digestive enzymes into their surrx3z4zve;gbq1*-s;t ycl6n booundings. The enzymes break down things such as dead;yl 3be14g *6 qs;xtozncv zb- and decaying leaves and the fungi then absorb the products. Which of these terms best describes these fungi?

  The illustration shows a rice culf s,ux1 7*fe2j hdwi2iq f+2jstivation system that eliminates the need for fertilizers, herbicides and pesticides by using ducks in the organic cultivation of rice. In ad udehx7 2jfqi, +2s2i1 fj*fwsdition, 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 the table whic 2(oxsszh 3uz7-a(oe ph gives the correct information about the different types of organis3zo s- 7o2aeus(hx pz(ms.

  A student set up an aqua1u/u gh ylur wy+uq 0a( (be put2ro3xx.7ze2.tic mesocosm using a commercially available seawater-filled glass orb,puz u.yuye7b0.3rl+uw( e2( /aqg ouxht x21r which included algae, shrimp, some 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 is/are true foxk07qn mju a2-9 cl/tar holozoic nutrition?
I. Demonstrated by saprotrophs
II. Involves complete or partial ingestion
III. Food is digested internally

  Which term refers to organisms that are both autotrop 8lqekqm z;:v2hic and heterotrophic?

  What are incisors used fo;p bno4+2qnfw6c1gnt ls0a x+ r?

The image below represents the sku1op/, uc.t-f q(jl qswll of a gorilla, 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 on pollen through extst*g :em 2fn9ca: a4zfracellular secretion of digestive enzymes and absorption of the breakdown products. Which:9:tgfz* 2a4s cmanfe statement describes the nutritional mode of this organism?

  Zooxanthellae are algae that live inside coral. Corals feed on the car9jzg2 ;n *(blp3wk qptbon compounds produced by zooxanthellae fro; n2*zpkjqg (9 3bptlwm carbon dioxide, water, and sunlight. Which describes the nutrition of these organisms?

  A student wants to set up an 2e7.fk nwo+2yc bqay6 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 from the area to set up the .qc w7b2nfyoe2ka 6+ ysystem 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 awmde6lio;p (ea .2 4n;hb, oxz6 ykjb.nd wanted to add some fish. 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 organjn ob. 4h6e x yda2; .blm,kzwi;p6o(eisms 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 voj-, l ;/ sfl8fnb: 4zmmdil.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 mixj6+ yb+( f+eneyog3protrophic and holozoic nutrition.

2.Describe how herbivores are adapted to eating plants.

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