Crabs, earthworms, mites anv9 obimtih/0o5n(yo9 d snails feed on the remains of dead plants and animals. What ty9y(i0ov boonh5 / m9itpe of organisms are these?

  Which of the following is not a saur 0+a3xff q2tprotroph?

  Some fungi obtain nutrients by releasing digestive enzymes into their surroundic6ovp wan. b49o- jh8gngs. The enzymes break down things such aso8- h6.co 9 pavwg4nbj dead and decaying 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 the need fook0xcxwt* +5 qr fertilizers, herbicides and pesticides by using ducks in the organic cultivation of rice. In addition, Azolla, an aquatic floating fern, is grown w o+* cx5xk0qton 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-mzzhtk 6 7q9fhu,h ;k/ev n5z correct information about the different types of or zz9n e6kh/h u5;7,h mzkqfvt-ganisms.

  A student set up an aqw)23 y4jjwn (hyz lwe5uatic mesocosm using a commercially available seawater-filled glass orb, which included algae, shrimp, some corals and gravel. The student placed it near a window to provide a )nh3elwwy(wzyj j 452light 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;yghwsqz, 7b 9 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 autotrophic and heterotroph+2o4o v s)5ibfsf4 teqic?

  What are incisors used fo c-8y43i l1l/dk12u gewl wnhmr?

The image below represents the skull of a gorilla, chimpanzee, and humanq (cox rwnt+/1.

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 unicellulh;k+e5o z1.r )tbm 5rir6 vjgmar organisms that feed on pollen through extracellular secretion of digestive enzymes and absorption of the bre1+5)mteh r;6mo gi rbk5.vzrjakdown products. Which statement describes the nutritional mode of this organism?

  Zooxanthellae are algae that live ;r m)eclk 6j-sinside coral. Corals feed on the carbon compounds produced by zooxanthellae from carbon dioxide, water, and sunlight. Which describes the );6-klmrejsc nutrition of these organisms?

  A student wants to set up an aquatic mesocosm using seawater to simulatfqes o2e6l 2k5e conditions in the food web (shok6 ee5lqofs 22wn 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 pond in the backyard and wanted to add some f :+ aucff)l9ootx+sc/ish. 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 phytoplankton or algae:+)fa tu9o o fl/xsc+c 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 processb3pia tux7+8u ll87jq 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 bet.ltzcg 0 ;by5((vqhbsween 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.