Crabs, earthworms, mites and snails feed on the remains of dead plants anv;fp(kuk zs gk.h/,*jd animals. What type of organiv(.zj kfhs ;ukg*,/kp sms are these?

  Which of the following is not a saprotroph3 wi gg)dftz;d,0ts9r?

  Some fungi obtain nutrients by releasing digestive enz e 9,3o4dttkdaymes into their surroundings. The enzymes break down things such as dead and de d4do9,ket3at caying 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 +ky43jcd g2 xx)k pp9dt*czd7.apm: w 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 be jgct4 +.9y 2*ck3dwxzpm dad7xppk):cause 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 tab v z,77fr4id-ce ohu;lle which gives the correct information about the different types of d-lh,e ourfv4i;c z77 organisms.

  A student set up an aquatic mesocosm using a commercia xyaisy9zn2zxn(*:9 hlly available seawater-filled glass orb, which included algae, shrimp, 2nx nzz9a *9yihs x:(ysome 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/.5dq rny5)+q4(cbmo8r wzyht are 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 autotrophic and heterotrop /fk5 .astqg -7qcfhpj/z6 ek*hic?

  What are incisors used fok+ 3:g.1vg 1cvth:ht fpvgy :tr?

The image below represents the skull of a gorilla, chimpanzee, and human. upuv (cu1ryfu5;).am

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 po ;dtwv u0r51qu n-jf3xvo dp),llen through extracellular secretion of digestive e,5vj f1d0vo);n rpux -q wudt3nzymes and absorption of the breakdown products. Which statement describes the nutritional mode of this organism?

  Zooxanthellae are algae that live inside coral. Corals fm) /b wc8zx-jkeed on the carbon compounds produced by jm)z/x c8w-kb zooxanthellae from carbon dioxide, water, and sunlight. Which describes the nutrition of these organisms?

  A student wants to set up an aquat2w8x h+llc04 (p1sncvm-iyd gic mesocosm using seawater to simulate conditions in the food web (shown in the image below) and test its stability. He used seawater and sand froignl4w(8l xdc2 +0p 1cms- hyvm 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 pomjhyb) 5 u*zo1/cc e.rnd 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 the phytoplankton or algae cey5zjbc o ).h1*/rumfor 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 dej9 1qxn mmadq(y:2s /;tgwa9g tritivores 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 between mim z(uf9im6 0 g0l1ktwsxotrophic and holozoic nutrition.

2.Describe how herbivores are adapted to eating plants.

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