Crabs, earthworms, mites and snails feed on the remains of dead plants y k)p,**l)zixt5ing 5ccuc z.b;tr4fo1d +eqand animals. ) zi fd4cxco,;*q * rgktn le51p)yu.b5ctz+iWhat type of organisms are these?

  Which of the following is not a saprotroph) wre miw py*cv.;)fc+?

  Some fungi obtain nutrients by releasing digestkxotg8 9 igh-(ive enzymes into their surroundings. The enzymes break down things such as dead and decaying leaves and the fungi then absorb the products. Which of these termo 89 ghxktgi(-s best describes these fungi?

  The illustration shows a rice cultiva eytxq(02d4 nrmc yjn:cf qtd,m *)c.;cr) de6tion system that eliminates the need for fertilizers, herbicides and pesticides by dcc tyx40 n.qrmmre)df:q yc*e,)t2nc ; j6(dusing 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 informatiou y*g.e.k6c zc):1;dbvq,i g)qbwu svn about the different types of organc6u y:cqw.ke gqgd s*b ,);b1v.uizv)isms.

  A student set up an aquatic mesocosm using a commercially available seawj015izjz n;n)dy/mox ater-filled glass orb, which included algae, shrimp, some corals and gravel.;m d 1zonxj)/5nzy ij0 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 holozoic)5sntd 4uqz p:dul0v g-d 6e2n nutrition?
I. Demonstrated by saprotrophs
II. Involves complete or partial ingestion
III. Food is digested internally

  Which term refers to oln s9 * ebsug.:naz+j.rganisms that are both autotrophic and heterotrophic?

  What are incisors used gzim n 9uh8l2)for?

The image below represents the skull of a gori.pzwq wbt-;r+k(3fp q)irb(c p- , rgxlla, 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 or92dz*kev-;s)d n3u reui 6 svsganisms that feed on pollen through extracellular secretion of digestive enzymes and absorption of the breakdown products. Which statement describes the nutritional mode of this organi er6k-udniv29u d);sz3s* ve ssm?

  Zooxanthellae are algae that live inside coral. Corals feed on dhfvt)iji)m/5,7f we23 lj tsthe carbon compou7 i, 3dft5ljwvsimtje h))2/fnds produced by zooxanthellae from carbon dioxide, water, and sunlight. Which describes the nutrition of these organisms?

  A student wants to set up an a*;p hybis ;u)squatic mesocosm using seawater to simulate conditions in the food web (shown in the image below) and test its stability. He used seawater and sand from the area to set up the syst)y;s pb*hu; siem 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 j i 6(k5,ncratand 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 for their supply ofc,6(j ra kitn5 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 detri3wfl r qfpkvb1h-j w7 cs7+96ktivores 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 mixotrophic and holozoic 7 p,gm(apyxnhn+ l 4y5nutrition.

2.Describe how herbivores are adapted to eating plants.

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