Crabs, earthworms, mites and snails feed on the remains of dea:n /,p:pi1r7fy lfiffd plants and animals. Wf:r1i :nfif/ ,lyppf7hat type of organisms are these?

  Which of the following is not a sa:zk .rgb dfup8g7-7 z,udjb y4protroph?

  Some fungi obtain nutrients.x 2ygcb/2ge dw-0k-bwn 8td(x yhva ; by releasing digestive enzymes into their surroundings. The enzymes break down things such as dead and decaying /2.cx(b;h-gd b geytwa0k-8x v2n wyd leaves and the fungi then absorb the products. Which of these terms best describes these fungi?

  The illustration shows am1vr6 xc *ero6k(uup (mu0j+k rice cultivation system 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 thm6kur(j+ruk v6x eo m*u p10c(is system, rice, ducks, and fish can all be produced for human consumption in one location.

  Identify the row in the tal7jo 9i1klvk3ble which gives the correct information about the different types oj3kvl 79k 1loif organisms.

  A student set up an aquatic mesocosm uscd-gz 0u8db7 hq22v+ffj 4e azing a commercially available seawater-filled glassz8f7udb2 fc-jh04ag+ e2q zvd orb, 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 foya(/d:01 xbp8ol docrr 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 autotroph+4f 0avwy8 ysia7 v)fuic and heterotrophic?

  What are incisors used for*,:p8q9atrcfofl1 l m?

The image below represents the sev: t vwn6 b0m/dl/04 q iwjwbumt7.4dszcb3.kull 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 organisms that feed on pollen throu;rm:2geh5ac -a vxvfsz1z /m)gh extracellular secretion of digestive enzymes and absorption of the breakdown products. Which statement describes the nutr1v x-eac5 zrzg;v) as:/mfm 2hitional mode of this organism?

  Zooxanthellae are algae that live inside coral. Corals feed on the carbon compouflk m6f6s1v 8 9k: nh:rrl)gyinds produced by zooxanthellae from carbon dioxide, water, and6i:rm)yh 8l96grf:kvlnfsk1 sunlight. Which describes the nutrition of these organisms?

  A student wants to set up an aquatic mesocosm u)1, hdupx +5 nnxtyq-ising seawater to simulate conditions in the food web (shown in the image below) and test in qx1i)x+nduy5p -h,t ts 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 pond in the backyard and wanted to add some fish. The mdambrm..t; 2fish would be predators of the pond and feed on the zooplankton (prey) growing in the pond. Zooplankton are small floating tr2.; mmb.admor 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 detritivores and saprotrophs obtaing59d6yz xdz v /enn+tpm s3(y( 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 bet:n a kj6m0+ ,pjgvfnk+ween 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.