Crabs, earthworms, mites and snails feed on the remains ofey jilo wbci 4p9z,aalv908yy/8(oc- dead plants and animals. What type of organisms are ioj4 z,-e(i8oabyl 9 pcyyl90vc / a8wthese?

  Which of the following is vukps9l fm(icqq8hf3- -c. w-not a saprotroph?

  Some fungi obtain nutrients by releasing digestive enzymes q0d w: +rbq6(ak 6bwive6f u0pinto their surroundings. The enzymesf6 +qv6r(u0k eq 0awpdbwbi6: break down things such as dead and decaying leaves and the fungi then absorb the products. Which of these terms best describes these fungi?

  The illustration shows a rice cultivation syzf+)juc1 k guiwq.3m,stem that eliminates the need for fertilizers, herbicides and pesticides by using ducks in the organic cultivation of rice. In additiocu ),kuf1i 3j zwgqm+.n, 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 all be produced for human consumption in one location.

  Identify the row in the table which gives the correct informa0x+ogp)z08 lz)v +af 9iidinltion about the differl89)0fpiz zn+o +v)gl0diaix ent types of organisms.

  A student set up an aquatic mesocosm using a commerci kg;ncym+(xje;b:,a tally available seawater-filled glass orb, which included algae, shrimp, some corals and gravel. The stnb(cx ajyg;k;t+,m:e udent 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 for holozoic nutriti )uu1t5moif ue*x:a2 ton?
I. Demonstrated by saprotrophs
II. Involves complete or partial ingestion
III. Food is digested internally

  Which term refers to organisms that are both au9hs+pv r)sc*6lb. lepj l0,ta totrophic and heterotrophic?

  What are incisors usedgidqn-mgom3 t3 g.9 v2 for?

The image below represents the skull of a :( ,5ychdlhdgu 9po*jgorilla, 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 extrackyl xvt:3.g8cellular secretion of digesc:v .ktl8x y3gtive enzymes and absorption of the breakdown products. Which statement describes the nutritional mode of this organism?

  Zooxanthellae are algae that live inside coral. Corals feed on the7ij/binnb mx79cd1 hh: 1i r:n carbon compounds produced by zooxanthellae from carbon dioxide, water, and sunlight. Which describesmri:jbx n/h7:hn 19ncdb ii 17 the nutrition of these organisms?

  A student wants to set up an aquatic mesocosm using seasx5/ euxz681a xt3 9xipy7laawater 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 added some small organisms tx5etxyz6iu p1x s98a3aa7/lxo 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 backy6kxh qjg ca 46ytp2:j.9x qp/kard and wanted to add some fish. The fish would be predators of the pond and 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 tc q p6t9yq2jkhpga 6x4jk. /x:heir 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 obtain nutrithu3p i*e)jicy/kb( 6 ,3b tqdgion.

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 mixotrq r9 e4.;vmonw)xz0 yxophic and holozoic nutrition.

2.Describe how herbivores are adapted to eating plants.

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