Crabs, earthworms, mites and snzdg41w s -cc2aails feed on the remains of dead plants and animals. What type of o w dazc-2sc4g1rganisms are these?

  Which of the following is not a sapro -kwq+,dex vis 6-3e (v j;wo(rrakl;ptroph?

  Some fungi obtain nutrients by releasing digestive enzymes into their surroun)hqy kvf1r2*lb1m(sv yann.2dings. The enzymes break down things such as de.a2nr)2nv( m h bqyyksl f11*vad and decaying leaves and the fungi then absorb the products. Which of these terms best describes these fungi?

  The illustration shows a rice cultivation syste21xv ax8(nppsie (u7r m that eliminates the 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 because it harbours blue-green algae which can fix atmospheric nitrogen. Using p 71 a2rx(pxnsu v(8eithis system, rice, ducks, and fish can all be produced for human consumption in one location.

  Identify the row in the table which gives thzg;kl f8u2l;c tx oe--e correct information about the different types ec2;8 k ulzgf-;-o xltof organisms.

  A student set up an aquatic mesocosm using a commerciall uta9nbt7n.sth u4mk 20pxj9.y available seawater-filled glass ork x.m. jntsatu2t90 nh4p9ub7 b, 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 holozoic nutrition? gyf5z13+*pcq m ;jibc8e g hq8
I. Demonstrated by saprotrophs
II. Involves complete or partial ingestion
III. Food is digested internally

  Which term refers to organisms that are b5t. f)rkqh.wh. cea1u oth autotrophic and heterotrophic?

  What are incisors used fifb62 /w ,yw5b,; wy6w itlaylor?

The image below represey9 .s r,dk/afbo ttmh/(u0-pj nts the skull of a gorilla, 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 organismsqg1q*9i4xcr8 xw fx 9c a/pl/d that feed on pollen through extracellular secretion of digestive enzymes and absorption of the breakdown products. Which statement describes the nutritional mode of this organf9wixq9l dxgx /1*r4 8qac c/pism?

  Zooxanthellae are algae that live inside coral. Corals feed on thjp 0 jzfl*qp6 3azcz:4e carbon compounds produced by zooxanthellae from carbon dioxide, water, and sunlight. Which describes the nutrition of th63 j4pf qz pzcl*j0za:ese organisms?

  A student wants to set up an aquatic mesocosm using seawate 8b w7v2r ta/vdbvz js;/p8-hpr to simulate conditions in th 8ptvbv-j 8b/r/2v7 hz spadw;e food web (shown 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 5;p, seovcm x.g s2dk4pond 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 for their sup, cmk p;s2dgs5x. e4voply 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 detritr0im;.jw gy*1yyqxe 5e n1sx)ivores 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 differew 6azv s)l 7u8becgc,: tr96gences between 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.