Crabs, earthworms, mites and snails feed on the remains of dead plants and anj*xnb7 v2jjc: imals. What type of nx72j *vcj:b jorganisms are these?

  Which of the followint1se:a b3kh tpdqx:k97*l: zvg is not a saprotroph?

  Some fungi obtain nutrients by r 9ctjk :6s6f;+ukh m*j1pmlwreleasing digestive enzymes into their surroundings. The enzymes break down things such as dead and decaying leaves and the fungi then absorb the kcprm h:;wj6k m 9flj16stu* +products. Which of these terms best describes these fungi?

  The illustration shows a rice cultivation system tha .snbn-.mn0t: l;l6ivqci :gjt eliminates the need for fertilizers, herbicides and pesticides by using ducks in the organic cultivation of rice. In addition, Azolla, an aquatic floating fern, . vnsg;.nibm 6:lcniltj-:q0 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 abovtxp .0z h;-tcj9 ocijc7d+ )lb+ru 3aut the different types 7 .ov-tc p bj0jh93ztui adc+)rlx c;+of organisms.

  A student set up an aquatic mesocosm using a commerci tm.2amnvb 1j,ally available seawater-filled glass orb, which included algae, shrimp, some corals and gravel. The student placed it near a window to provide a light source. Which of n m12ma j.,vbtthe 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 holoksubj rte g /)*85ae28ie 6atrzoic nutrition?
I. Demonstrated by saprotrophs
II. Involves complete or partial ingestion
III. Food is digested internally

  Which term refers to organisms thatat 0k6e/azmambm:a3y(;: u ra are both autotrophic and heterotrophic?

  What are incisors used hzi97msvw r(5.jj at1 for?

The image below represents the skull of a gorilla, chimpanzee, and rg5x:f9w trr zbp1a1r**q v7zhuman.

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 unicellularxc kgh-,3;cys organisms that feed on pollen through extracellular secretion of digestive enzymes and absorption of the breakdown products. Which statement yhg scc-;k, 3xdescribes the nutritional mode of this organism?

  Zooxanthellae are algae that lqic n z duvz,0yd7w253ive inside coral. Corals feed on the carbon compounds produced by zooxanthellae fi vuc ndq307w,d52yzzrom carbon dioxide, water, and sunlight. Which describes the nutrition of these organisms?

  A student wants to set up an aquatic mesocosm using 7gjcyx u n n6tg:w)7-wseawater to simulate conditions in the food web (shown in the image below) and test its stability. He used seawater and sand from the area ton6cx: ww g-yt) 7unj7g 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 and2nooj)o)8grc .c7r+fsh3 b oc 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 fcochs)bofcojn 3rgo2 r. 7 )+8or 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 zxy-whoq- * 1lby which detritivores 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 nutr6kqld -s1agi;ition.

2.Describe how herbivores are adapted to eating plants.

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