Crabs, earthworms, mites and snails feed7xvx7; *81*y0cya kbd0vzz , raueqbm on the remains of dead plants and animals. What type of organisms are thes*yz e77ara0, vkzmxcvd;b1*yq 80bux e?

  Which of the following is not1)a43kyeg u , /bbs gr9yq6qion 64 xhxgp8a:f a saprotroph?

  Some fungi obtain nutrients by releasing ddki g z 4tq,e (/1xnltwzo*9w8igestive enzymes into their surroundings. The enzymes break down things such as dead and decaying leaves and the zglwo(, t1de i* /nwk4tz8xq9fungi then absorb the products. Which of these terms best describes these fungi?

  The illustration shows a rice cultivation system thaov0 v(mv 9 dy p)1vjuqo4gjzy4l ;f1,st eliminates the need for fertiliy gd o ;,mlfjyvoj) v(s1v9 01p4qvuz4zers, 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 consumption in one location.

  Identify the row in the table cezwa0-b+j p(8bm:f3iab/wm which gives the correct information about the different types mzjbm pwai(8acfbw : 3 /-b0e+of organisms.

  A student set up an aquatic mesocgk4 3 qd-8krjhosm using a commercially available seawater-filled glass k8q3g h-rkdj 4orb, 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 for holomg/29 3xbca.6ac qszwcad 5,azoic nutrition?
I. Demonstrated by saprotrophs
II. Involves complete or partial ingestion
III. Food is digested internally

  Which term refers to organisms that are both auvdu)y+i 91n/yjgeq 7utotrophic and heterotrophic?

  What are incisors used f)h xo9ro, o6xfor?

The image below represents the skull of a gos qdc ),ownovj (r*2bd.ijr 4.rilla, 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 throu x92 nzdh:kut,gh extracellular secretion of digestive enzymes and absorption of the breakdown producthntxk u9 2:z,ds. Which statement describes the nutritional mode of this organism?

  Zooxanthellae are algae b fd6x*wjuy ;4 +v6rf3b8*6k vqrupklthat live inside coral. Corals feed on the carbon compounds produced by zooxanthellae from carbon y j*d vb*u+68p6f k4;uvrrxqkl w6fb3dioxide, water, and sunlight. Which describes the nutrition of these organisms?

  A student wants to set up an aquatic mesocosm using seawater to x 7l546yxnd)5 fnu/pbqgdtn3 simulate conditions in the food web (shown ixnl37)/nuy 5pgxq 5f6n4 tbddn 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 pond in the backyard a fs0iynu ,;5fznd 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 the punsz,; y 5fif0hytoplankton 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 nu1p k*ry ,ik1qeua3bry6d o1 i-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 mixotrophic and ho 4xm)br hidfa .(w/:omlozoic nutrition.

2.Describe how herbivores are adapted to eating plants.

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