Crabs, earthworms, mites and snails feed on the remains of deadmbza qw r*oao9;x0+ (h plants and animals. What type of organisms are these?(9w aq+;rxzm*oa0o hb

  Which of the following is 68s z ulo5;ngznot a saprotroph?

  Some fungi obtain nutr31.;l msu si tlry;6x,:xx hnbients by releasing digestive enzymes into their surroundings. The enzymes break down things such as dead and decaying leaves and the fungi then absorb the prod: l,rx1bmusxi l;s6xn t y;3h.ucts. Which of these terms best describes these fungi?

  The illustration shows a rice cul nvda(v3 gn 9kzu:5)y1 os b4rkkjr4(etivation 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 a3(vvy5sknk )b:4 1aon rugerd 9z4kj(tmospheric 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 cor o atc6gqg9o645qo: pfw.ik.mrect information about the different types. m 4ag. gqowc9k5ooqit6:fp6 of organisms.

  A student set up an aquatic mes6q2z2yjo9 uhsocosm using a commercially available seawater-filled glass orb, which included algae, shrimp, some corals and gravel. The student placed it near a window tohzj22 9uyq6 so 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 nutrition?)85fn, rzwqpkp:5lo h
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 heterotropfsh kbl0k-.,msd,g *thic?

  What are incisors usx7m.hxhxmrayrhnetk5, * ,3:ed for?

The image below repr(j3alb -m:npw bz mqf9e ih7++esents the skull 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 organisms 56mekc2dsb9hfv b )i7 that feed on pollen through extracellular secretion ofbb27fvmk ei6h9cs )5d digestive 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 the elb -f7ma,i ;wcarbon compounds produced by zooxanthellae from carbon dioxide, water, and sunlight. Which deb7f;, lwiem -ascribes the nutrition of these organisms?

  A student wants to set up an aquatic mesocosm usrtv6p2k)xp.t,5 vpw5hwh sl-ing seawater to simulate conditions in the food web (shown in the image below) and test its stability. He used pvs)p5 h,wh5 tkw2p- 6xrvtl.seawater and sand from the 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 wff.y un+r is 2pe6pm2/anted 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 phytopmfi+.f6 p2eusrp y2/nlankton 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 obtain nut z*bmp7 1 di7fk 4qjhgst3so*pw1f,y*rition.

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 m 4 (f4dbizfab(ixotrophic and holozoic nutrition.

2.Describe how herbivores are adapted to eating plants.

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