Crabs, earthworms, mites and snails feed on the remains 3m2yn ir 0bos+of dead plants and animals. What type of organisms aren+ 3 o2sym0rib these?

  Which of the following is not a jfd7u3.gs (v6b ld;s wsaprotroph?

  Some fungi obtain nutrients byb345t-1a dczo.he wzq releasing digestive enzymes into their surroundings. The enzymes5zeqh-1boawt z4.3 dc 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 cultiva 73ovqf.apzm8tion 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 all be produced for human a7fpq3 om8z v.consumption in one location.

  Identify the row in the table which gives the correct informatioxu*b;x yj w83nn about the different ty; x 83bx*ujynwpes of organisms.

  A student set up an aquatic mesocosm using a commercially availabxihmcw35xmb, 3a ug3 2le seawater-filled glass orb, which included algae, shrimp, some corals and gravel. The student placed it near a window guacw3bixh, m53x m 23to 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 truosr 5)5pnm7 bbz 4gmx7e for holozoic nutrition?
I. Demonstrated by saprotrophs
II. Involves complete or partial ingestion
III. Food is digested internally

  Which term refers to or+e eh3j1hs m9eganisms that are both autotrophic and heterotrophic?

  What are incisors used f0;ns gqq; i,pdor?

The image below represents the skull of a gorilla, chimpanzeecmzt6 4 f07vi-q9btzy , 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 extracellular se;wfzzb6wl7wic ldakq 6- +m 67cretion of digestive enzymes and absorption of the breakdown products. Which statement describes the nutritional mode of this organism 7 a6dzww+ 7-6 ;icfqwz6mblkl?

  Zooxanthellae are algae that live inside coral. Corall 7j(d qm.43b/nrt(( sp rty/)1zh)f ttam zmws feed on the carbon compounds produced by zooxanthellae frq (rl/m)pz3wsz/mf7 t( hd4n mt1jb(tty ar.)om carbon dioxide, water, and sunlight. Which describes the nutrition of these organisms?

  A student wants to set up an aquatic mesocosm usi zdolpn-s jo ,-7kgw4.ng seawater to simulate conditions in the food web (shown in the image belowsgooljd 7z-k4,n -w.p) and test its stability. He used 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 an x*nynv, wa-3id wanted to add some fish. The fish would be predatoy -i,n3v*nwxars 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 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 n0 6k; :lselecqutrition.

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 mixt j 7 rgnhrv(icgwv+m)49;7footrophic and holozoic nutrition.

2.Describe how herbivores are adapted to eating plants.

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