Crabs, earthworms, mites and snails feed on the remains of dead plantv.mp 1 fz524b(6r e otoe4ffors and animals. Who6tem(r r1 ze4o.obfp4 f52v fat type of organisms are these?

  Which of the following icz ni;5rk-;ogc s80c+5qyl gh s not a saprotroph?

  Some fungi obtain nutrients by releasing digestive enzymes j,otm28bn9kc6fx vo 3 into their surroundings. The enzymes break down things such as dead and decayingv9n o 3ftjx2om,8c kb6 leaves and the fungi then absorb the products. Which of these terms best describes these fungi?

  The illustration shows a rice cultivation system that eliminates thue +bpbg5yp-s- xt+a *e need for fertilizers, herbicides and pesticides 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 consu*gx utb+p +a5-spe y-bmption in one location.

  Identify the row in the table which --lf ;fdjwmp8dj c93hgives the correct information about the different f pw8;d-d m-f hjj93lctypes of organisms.

  A student set up an aquatic mesocosm using a commercially ava:ubwnda 9t guz51 p 2dl/r8 8ma7ra2ktbvt;*oilable 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 folazb dm: 289r uolbkv5a8*trp7/tdt1wgu; 2anlowing 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 for holozoicfpngi,f(5ya4c8: x z x 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 and hetehnniz6c71qk 3fx, xa*rotrophic?

  What are incisors used f*im:ri/x(go 5er3 isqor?

The image below represents the skull of a gorilla, chimpanz/m81bhj yqun*ltfoi xqd48 up4 3 :nofo*n96 kee, 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 o;wo p;2gtskghu 48ce.n pollen through extracellular secretion of digestive enzymes and absorpt4 kge8sc g;pu;h.wot2 ion of the breakdown products. Which statement describes the nutritional mode of this organism?

  Zooxanthellae are algae that lm9+ralpa / tx q99b.aeive inside coral. Corals feed on the carbon compounds produced by zooxanthellae from carbon dioxide, water, and sunlight. Which describes the 9bmax.r 9aa9p+t/q el nutrition of these organisms?

  A student wants to set up an aquatic mesocosm using seawater to sim 9ctngzjs2yrg/:x;u0ulate conditions in the food web (shown in the image bel gn0r92;:tzyu/g sxcjow) and test 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 ,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 yivn cvg5 k:7p;o/y *wfish 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 i /;vvkwyc5yg p*o7n: 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 procest 0fuuqsl,0bx.gi 6:k s by which detritivores and 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.Outline the differences beh n1zna;v*v5 sxz ,otmd,d0)etween mixotrophic and holozoic nutrition.

2.Describe how herbivores are adapted to eating plants.

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