Crabs, earthworms, mites and snails feed on the remains of dead pi/ nr9 p32, /qc 9dpz8wla h-gdiz4vgix31wjulants and animals4v -i3z3 wiuad8 zr, g//pdlxwhpc99 n 2qj1ig. What type of organisms are these?

  Which of the following is not a saprotro0bzqo5 kta6t ztw13 tf:or18 mph?

  Some fungi obtain nutrients by releasing digestive enzymes qe(db ,tzm, 0or4o(son5w dh86ppub: into their surroundings. The enzymes break down things such as dead and decaying leaves and the fungi t486s 5we(t0zoq,o hbdn,ud m rp o:(bphen absorb the products. Which of these terms best describes these fungi?

  The illustration shows a rice /ygyke4k7+pz. o)q4-x vxj ws 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. e p. zjgw)vys-yx+xo4 4q/kk7Using 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 smtjv.n-g0o o ho l398about the different o8o39 tj-l.og 0snhmvtypes of organisms.

  A student set up an aquatic mesocosm ;7fhqd, k9d bzd7t8 9a-iqhykusing 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. Why;89dd 7bqztf-kh ,k di7hqa9 ich 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 qusy; :y 3hu95i fwjs.mg(d3jis/are true for holozoic nutrition?
I. Demonstrated by saprotrophs
II. Involves complete or partial ingestion
III. Food is digested internally

  Which term refers to organiluic .52vcgk1 zbx.x4q21l b rsms that are both autotrophic and heterotrophic?

  What are incisors usedkn9ykh,fsuyy:u2 k ;/ for?

The image below represents the skull of a gorilla, chimpanzee, yg.dir nc94lob l,q/+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 extray2 nel0ijo)vj 9xgw82 cellular secretion of digestive enzymes and absorption of the breakdown products. Which statement describes the nutritigo0j v8ne)ylw9j xi2 2onal mode of this organism?

  Zooxanthellae are algae that live inside coral. Corals feed on the carbon soa0f32 +8ldu,xc ( nez2w g( *ep3aeznzz2vdcompounds produced by zooxant2l3, gpav+2 w8z 3fne0z2oaxdn z d(ceus(z*ehellae from carbon dioxide, water, and sunlight. Which describes the nutrition of these organisms?

  A student wants to set up an aqp2jsu)+d ytf/tb u b+(uatic 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 systet(j+ fds 2ybtu+b)u /pm 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. Tt* dg0z p5zb7hvhiq+9he fish would be predators of the pond and feed on the zooplankton (prey) growing in the pond. Zooplankton are small floatin *qzz0vb 9hd+g7tph5ig 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 )c;ptm+ e1tp 4cyr.uh 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 andt xcjwi4 40bw. holozoic nutrition.

2.Describe how herbivores are adapted to eating plants.

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