Crabs, earthworms, mites and snails feed on the remains of dead plants)sn0p4hd,h b3sp a.8uigovdwzsz e/ 6-t1 e ;k and animals. What type of organisms a6dn.vt/a igs- 14 zkhs) peud3,p e8b0swzo;hre these?

  Which of the following is not a saprotroph619 /pkoyxv q1kxns9p ?

  Some fungi obtain nutrients by releasing digestive enzymes into tl ut/syt,t:s ;heir surroundings. The enzymes break down things such as dead and decaying leaves and the fungi then absorb the products. ;yt:/tt ul s,sWhich of these terms best describes these fungi?

  The illustration shows a rice cultdo9wd1x6 kt, qivation system that eliminates the need for fertilizers, herbicides and pe6wqt1d,k xo d9sticides by using ducks in the organic cultivation of rice. In 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 the table which gives the correctdbt n;a8 gv,-t information about the different typn, a; -ttgd8bves of organisms.

  A student set up an aquatic m) qt7ij)*xy meesocosm using a commercially available seawater-filled glass orb, which included algae, shrimp, some corals and gravel. Thet )7e*ij) xqym 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 forb7o 4j8lk*k yu 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 autotrophic n jjm)ne(s jic6/s, x+and heterotrophic?

  What are incisors used for?eo+d:8oj d )mu4;zxni

The image below represents the skull bt hofh0h-htz6;a-3j 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 extracel pwe1-p2khef:/ wu0i ylular secretion of digestive enzymes and absorption of the breakdown products. Which statempeeu: pww /h1k-yif02ent describes the nutritional mode of this organism?

  Zooxanthellae are algae that live inside ftpo0x(za/pzzt6ws1y 3n 9 e )a8jsh 0coral. Corals feed on the carbon compounds produced by zooxanthellae from carbon dioxide, water, and sunlight. Which desej10on3) (9phazz8xy twz/ pft0sa6scribes the nutrition of these organisms?

  A student wants to set up an aquatic 2ipx1oc htnt q54m/s7mesocosm 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 system and added 1/ohi74tsx52q p ncmt 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 ftz lq r)h0,yhxpy+v y9max,() 52ke qd)(ery eish 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 dependent on the phytoplankph+ tram( 0zy l)9)ykey ,,)xxy5dvq qr2h(eeton 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 nu/dc l04aagg +ltrition.

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 nutr 8bil 7(yuw 8jaom)tn5ition.

2.Describe how herbivores are adapted to eating plants.

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