Crabs, earthworms, mites and snails feed on the remains of dead plants and anima:wc6rdx /t;v y5zlojfvjh8:m0e 1/a z ls. What typez/8fm yl5 e;h61z:/ jov:tvrxjad c w0 of organisms are these?

  Which of the following is not a sd, f9wnd ,9i )zv;cmouaprotroph?

  Some fungi obtain nutrients by releasibx0vpv*1d*sakt. r4 kng digestive enzymes into their surroundings. The enzymes break down things such as dead and decaying leaves and the funt* *raksp. d v0kb1v4xgi then absorb the products. Which of these terms best describes these fungi?

  The illustration shows a ri0d+qhy,-eimoaxi2 :d ce cultivation system that eliminates the need for fertilizers, herx2,y-dqidioa + :eh0 mbicides 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 informat9 g74f; r-vg nr8xvejt4j.gdh ion about the different typneg-jgh 4tvv 8j g ;d49r7xf.res of organisms.

  A student set up an aquatic mesocosm using a commercially available seawateryltmc-, 9v4immi exvlu/,gdc() 0 t7e -filled glass orb, whichvyxl( mce-l,7/) v 0ietgti9mcd4u, m 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 followingsubz(d)r6yt-hq o rompf-/2/ is/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 th-9xhz1sjprm i: zt95eat are both autotrophic and heterotrophic?

  What are incisors used for nppgb u+2udo03 afblg* 6)nq7 kb6rt+?

The image below represents the skull of a go2m kbe+i x jja4k6oc 7*(mkjqjo+)c5rrilla, 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 unicellularb1qw1oa3)/7jad4 a jfuq, ahe organisms that feed on pollen through extracellular secretion of digestive enzymes and absorption of the breakdown products. Which statement describes the nutrita4q)o,bh71 13 jeafj u/wadqaional mode of this organism?

  Zooxanthellae are algae that l,g p9lbdvb+-zp7w:je iau ;f3ive inside coral. Corals feed on the carbon compounds produced by zooxanthellae from carbon dioxide, wajp,-d w fv+;z9u bg:a37iblepter, and sunlight. Which describes the nutrition of these organisms?

  A student wants to set up an aquatiopg7yed dz mc;n/.) 1gc mesocosm using seawater to simulate conditions in the food web (shown in the image below) and test its stability. He use ddynoz1 .gm/cg )pe;7d 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 w,vkxf3p8ju vafi3mk cfmhnu *2vve6 + r0 .d76anted to add some fish. The fish would be predators of the pond and feed on the zooplankton (prey) growing in vvm uf+knf6pru2j8v3ad 6,0 c 3khe*x.vif 7mthe 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 detritivor6 .i;ghcbz,kx es 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 betwee **mwo:b/ncowb-9;bebux x6l n 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.