Crabs, earthworms, mites and snailb,sxb.um 3 /yzkf )9rys feed on the remains of dead plants and animals. What type of, 3b/byrs)fy .9zkx mu organisms are these?

  Which of the following is not a saprok52k mq fg8(zvtroph?

  Some fungi obtain nutrients by releasinbf4b5qpq8- o q/l zrv0g digestive enzymes into their surroundings. The enzymes break down things such as dead and decaying leave0 br zf4obqvqqpl-/85 s and the fungi then absorb the products. Which of these terms best describes these fungi?

  The illustration shows a rics.xi tup abo..nhgz2*1 ( h:uwe cultivation system that eliminates the need for fertilizers, herbicides and pesticides by using ducks in the organic cultivation of rice. In addition, Azolla, an a z*ou(uwn:as1.x bt2phi . hg.quatic 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 whic y8nsv m*k;ox )xs+n6sh gives the correct information about the different types+msn) 6vsx;y x8*knso of organisms.

  A student set up an aquaao8 (g (lgc8dn7u9 xnntic mesocosm 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 followin9aogludc(8 87gnx n n(g 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 tr0q1.-3uo q.bgnus7y 3w wsiokue for holozoic nutrition?
I. Demonstrated by saprotrophs
II. Involves complete or partial ingestion
III. Food is digested internally

  Which term refers to organisms x9l50tip w 9ysthat are both autotrophic and heterotrophic?

  What are incisors used6ot t9b6zyw x8ywixf )* ,a7re for?

The image below represents the skull of a gorilla, chimpanzee9jq8+8f v vxzs, 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 unicellu0u b a 1fys1x w.ri)jskf2j0t+)b ua2klar organisms that feed on pollen through extracellular secretion of digestive enzymes and absorption of the breakdown products. Which statem0uwajyf 220r)+k) 1 .ksas1ibfut xjb ent describes the nutritional mode of this organism?

  Zooxanthellae are algae;0ed9la p(v ;zrc5iiv that live inside coral. Corals feed on the carbon compounds produced by zooxanthellae from carbon dioxide, water, and sunlight. Which describes the nutrition of these organis0vic( v r9;5pdez ai;lms?

  A student wants to set up-sb--.r. zl uxk9 xuji an aquatic mesocosm using seawater to simulate conditions 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 adu-l.- .ju9 br- isxzkxded 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(9m.ocm5 -r zg.f.xo mq - beyft5lf/l backyard and wanted to add some fish. The fish would be predators of the pond and feed on the zooplankton (preym-.eloffct/lfobyqr. .- 55x zgm (m 9) 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 (,kaka0fjg38 dl h)uo 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 mixotroqlv8euy3x , r8s(ab3qphic and holozoic nutrition.

2.Describe how herbivores are adapted to eating plants.

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