Crabs, earthworms, mites and snails feed on thdcd) xy1xnr;8 e remains of dead plants and animals. What type of organismd x1r xc;ndy8)s are these?

  Which of the following is not a saprotroph*ysl) +ote7ty?

  Some fungi obtain nutrients by releasing,sin-/jg h ;c4- os fu1n.tjzp digestive enzymes into their surroundings. The enzymes break down things such as dead and decaying leaves and the fungi then absorb the products.jss/nhp j 4gnt.foc1u-;,-z i Which of these terms best describes these fungi?

  The illustration shows a rice cultivation system that eliminates the wp.85d;zq cd+avy5 qr need for fertp;y8drz5c+5aq wq.v dilizers, 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 which gives the correct information about the r7bj(4,jgno37iehvg qual7j: s 40ch differesjjhn q73e(74 ja4u07lcgvgr: o, h ibnt types of organisms.

  A student set up an aquatic mesocosm using a commercially available seawato z*2ihcxl- a3er-filled glass orb, which included algae, shrimp, some corals and gravel. The student placed it near a window to provide a light source. Whix izoa-c2h3*lch 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 trueio 9r (4098bmyhvv:ex4k bldi 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 auee qo:nap/3) q9p9slz b/.r l0 r;lzfttotrophic and heterotrophic?

  What are incisors used :n .bs p3q*n/hj.6gulbe)sh o for?

The image below represents the skull of a gorb9lsn:4o0ws ;nx q vz(0uefb) /cs5oqilla, 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 extrac6fodhycz fpvi4n1 (g +/5t ,vcellular secretion of digestive enzymes and absorption of the breakdown products. Which statement describes the nutritional mode fvfc/opi, 6gvh+dz 4 15nct(yof this organism?

  Zooxanthellae are algae that live inside coral. Corals feed on the ca;hcq wgwj0 :-vrbon compounds produced by zooxanthellae from carbon dioxide, water, and sunlightc:;w jvg -wq0h. Which describes the nutrition of these organisms?

  A student wants to set up an aquatic mesocosm using seawater to simuygn9b )lbs/1vch tz .-late conditions in the food web (shown in the image below) and test its stability. He used seawater and sand from -9yt1.bbzvc/ hnls) g 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 fish1a 5 xw) mdky3zz8ow3r /iptn6iq:2hl. The fish would ) 6q35:lkzh82xod/ waw myitprzn1i3be 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 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 saprotropn7 i4a sn2nam1hs 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 between mixotrophic and holozoic nutritiong87*e (p v-7igg tepxe-xz1iu.

2.Describe how herbivores are adapted to eating plants.

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