Crabs, earthworms, mitqdcq/c* ue07 a2)n lqj+xki83 t7qsqpes and snails feed on the remains of dead plants and animals. What type of organisms arejt a d3/qqs 0 +*p8kqn7)cei2ux qlq7c these?

  Which of the following isvn; coaw06wh/t n s93-tv x9jp not a saprotroph?

  Some fungi obtain nutrienobj 6nrwj+9 ;w0 x-lmets by releasing digestive enzymes into their surroundings. The enzymes break down things such as dead and decaying leaves and the fungi then absonr6bw ; lmjxw0 j-eo9+rb the products. Which of these terms best describes these fungi?

  The illustration shows2xqm/an3nkuhtk7xx; n 9 a/v+ a rice cultivation system that eliminates the need for fertilizers, herbicides and pesticides by using ducks in the organic cultivation of rice. In addition, Azolxk/7a na9 /x2h xmtq3vk +n;unla, 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 cou, f 44nm)gl( rk64 c0i xtyceh79yy5xnh x4wbrrect information about the differe,hx u mb 0l5 kfnh4y7gtn c y)6(xxi4e4y4wcr9nt types of organisms.

  A student set up an aquatic mesoc5kz f;6wy +cz. opa;ntosm using a commercially 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 the following statements are tk wn .t;6 p+zzfyo;a5crue?
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 nutri3i7pz ;+gfg v 2nes8hhtion?
I. Demonstrated by saprotrophs
II. Involves complete or partial ingestion
III. Food is digested internally

  Which term refers to organisms that are both autotrophic and heter qukc+nz f+9z9.ht0 yz;2rlpgotrophic?

  What are incisors used for?nxx ,9x:.. tioexdx+a+(m xxnjc;or /

The image below represents the skull i u28o,l zjf,j4c1wqaof 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 through extracel vzc 06b.o5zv0j i6wl(u wqtg,lular secretion of digestive enzymes and absorption o6qcizgozw5u6w0tv0j. (b l ,v f the breakdown products. Which statement describes the nutritional mode of this organism?

  Zooxanthellae are algae that live inside coral. Corals feed on 6z8um rmoo4( fthe carbon compounds produced by zooxanthellae from carbon dioxide, water, and sunlight. Which describes the nutrition of thesef 4o6rm( m8ouz organisms?

  A student wants to set up an aquatic mesocosm using seawater to simulate condii*4pnp q h/h6m5tv4r2o g g3wltions 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 system and added some small organisms to the mesorvwtp l4ni hgh q46*52 o/mg3pcosm.


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 :* )qr3w nv9z0 mmifmffish would be predators of the pond and feed on the zooplmfiwf3 0m *zmnv:q)9 rankton (prey) growing in the 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 detritivores and saprotrophs obtan h3taoi2,7bg0f+ ym xq)zj *uin 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 nuc ;rhqjrnb n0:6an*-cn i )6-cugjr6rtrition.

2.Describe how herbivores are adapted to eating plants.

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