Crabs, earthworms, mites and snails feed on the remains of dead plants and anii;xk/ *9- m6fzg owkctmals. What type 6ox gw/i*fc ;t9mz- kkof organisms are these?

  Which of the followiny/*vy 3 ci,srng is not a saprotroph?

  Some fungi obtain nutrients by releasing digestive enzymes into -m rw8rac6 .zdtheir surroundings. The enzymes break down things such as dead and decaying leaves a w-a8m.dc6rzr nd the fungi then absorb the products. Which of these terms best describes these fungi?

  The illustration shows a rice cultivation system that eliminates the nec2a 6hf- pq m*-cgt2ched 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, ricmg*c hcch2 tq-6paf2- e, ducks, and fish can all be produced for human consumption in one location.

  Identify the row in the table which gives the correct information about th xz6b; hur:5z9vlibk1 e differenz bbi 9 x;h51uk6v:lrzt types of organisms.

  A student set up an aquatic mesocosm using a commercially acr/xb suf+ +bq-u-t8b8 cmv1g vailable seawater-filled glass orb, which-x u fq+8vrutb-gbs b1 c/8mc+ 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/aref4rjfz3df b5: 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 both autotroucy dryy/r+uz:* 0 *jgphic and heterotrophic?

  What are incisors used fo;sk9 hgnb.aca xku0(vl x4 b7(r?

The image below represents the skull of a gorilla, chim8( efh)5wx.*fob a8u:fcezzm panzee, 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 ext*z*ecq a8 7ur bcc7*pnracellular secretion of digestive enzymes and absorption of* qzb nac cu8ce*7*pr7 the breakdown products. Which statement describes the nutritional mode of this organism?

  Zooxanthellae are algae that live inside coral. Corals feed on the carbon compoup+d, 26n/j h7gz glbok( 5smnfgue(u+nds p7ep s/gu d 62+ungg zno(mlh+jfk 5b,(roduced by zooxanthellae from carbon dioxide, water, and sunlight. Which describes the nutrition of these organisms?

  A student wants to set up an aquatic mesocosm usin)uc(g6mwf *ljurw*; vg seawater to simulate conditions in t6**wjcw) ur(lf;g umvhe 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 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 pog)aq vc 84 a(y-rqqgj)nd in the backyard and 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 organisms that are dependent on t)y4cg vqarjgq(- )qa8 he 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 nuyts:p3b o4ia,trition.

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 mixotr e 0mzj:lns8h j/pot+zt5 cajn1wyifx *4/)u6ophic and holozoic nutrition.

2.Describe how herbivores are adapted to eating plants.

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