Crabs, earthworms, mites an5xj+i;xwan k *d snails feed on the remains of dead plants and animals. What type oj 5inaw +x*k;xf organisms are these?

  Which of the following 0m7c. q-cro lmis not a saprotroph?

  Some fungi obtain nutrients by releasing digestive enzymes i-lahr)5mio;gciutg q+6lm k-z0bxq :4 c pi ).nto their surroundings. The enzymes break down things such as dead and decaying leaves and the fungi then absorb the products. Which of these terms besi)mqh-.lba u) z0+o5xiiqtp klgc:;gm r46-ct describes these fungi?

  The illustration showsv fat+gd;- ix0 a 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 this system, rice, ducks, and fish can a+fx ti;dva- 0gll be produced for human consumption in one location.

  Identify the row in the table whicoi2 leryfpg:y8 5 b.,z44vls bh gives the correct information about the different typ,se4giyrb425.byl :pvof8zles of organisms.

  A student set up an aquatic mesocy n uf0b4p2v5xosm using a commercially available seawater-filled glass orb, which included algae, shrimp, some corals and gravel. The student place5 fyvxu pn20b4d 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 followin iarlwj.o94f f2;d ,lhg is/are true for 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 autotrophic and heterotrophich 3tkkvh09 9p uls:c.9 uoed5c?

  What are incisors us,2kq,rs tk,h aed for?

The image below represents the skcvh* / x-htzx p*xli w51b9v/l iqtg-)ull 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 orgfvejd2z3 *e 3hanisms that feed on pollen through extracellular secretion of digestive enzymes and absorption of the breakdown products. Which statement describes the nutritionalvz 2de* hj3f3e mode of this organism?

  Zooxanthellae are algae nj2c rl(2m (z:l e-sqhs/ lkzmcf,),tthat live inside coral. Corals feed on the carbon compounds produced by zooxanthellae from carbon dioxide, water, and sunlight. Which describes the nutrition of thes mf/ c -hlzj nt2c,:m2e(k,sslz( lqr)e organisms?

  A student wants to set up an aquatic mesocosm using seawater to zn0ap)p kwen hkw0n)2t j5g(wd/;oq 1simulate conditions in the food web (shown in the image below) and test its stability. He used seawater and sand from th1d0(p h5nt pw j;oken0n)gzqw2ak /)we 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. ufb0 tofxa.7mt6+9wn The fish would be predators of the pond + 7m0tn9fwubotx6 a.fand 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 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 saprotr: 4(o uto/bdykmg5i ti.r2 iv;ophs 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 differysg l+u54p*8 i 2/n8g msvjqnmences between 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.