Crabs, earthworms, mites ;q3 h8 vr 0qcjvu 5ewtr;4nvm/and snails feed on the remains of dead plants and animals. What type of organisms are these/ 0j;wrrn 5qe 3v4cv8utq;vm h?

  Which of the followingrivd72r .6 j qjn7:ehe is not a saprotroph?

  Some fungi obtain nutrients by releasing digestivxz)bt qri,2h ,e enzymes into their surroundings. Th2z,hb xitqr),e enzymes 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 ho9f3ipy:+6fbmb wk,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 tfbi hmbyk+93,wfo:6p his 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 in+ 9w+ np;kafmfformation about the differenf+p;+mk nfa9 wt types of organisms.

  A student set up an aquatic mesocosm using a commercially availae-hd6f fyk5/ ge(znta x ),-nable seawater-filled glass orb, which included algae, shrimp, some corals and gra-t/5a n) fnz 6e( gx,y-ekhdafvel. The student 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/a64r c s:cvaja18q9si mre true for holozoic nutrition?
I. Demonstrated by saprotrophs
II. Involves complete or partial ingestion
III. Food is digested internally

  Which term refers to organisqhg0 lt89z9c6al f1uv ms that are both autotrophic and heterotrophic?

  What are incisors us6 j w670g1oce wbqi-b2wk*gyxed for?

The image below represents the skull of adhp adj *1-u nn5-f5(3 kuahsa 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 x2zxnus92aa so3a0 ook9 z,0vorganisms that feed on pollen through extracellular secretion of digestive enzymes and ab asxo,azo0kxv09a92zs 3 ou2 nsorption of the breakdown products. Which statement describes the nutritional mode of this organism?

  Zooxanthellae are algae that live inside coral. Corals feed4atn d1pve1ctdm6na0w)s3n -5 c )qkq on the carbon compounds produced by zoo n)eqq1tsp3ncnatvw645kacmd-1 d)0xanthellae from carbon dioxide, water, and sunlight. Which describes the nutrition of these organisms?

  A student wants to set up an aquatic mesocosm using seawater to simulaz 0 ,1m8k)*amldfwayr/q g +l+-dhgp wte conditions in the food web (shown in the image below) and test its stability. He uskqg r ,1 fm a80yz+dmlh+wlgw*-/d)ap ed 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 a2v; ahbim+94v0png2 z 4tobodx8jr 4pnd wanted to add some fish. The fish would bev+rpoh24 92 jatozi4mb8g0dn4p b v ;x 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 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 ande/1udw8* 4sw-rcd e qk saprotrophs 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 and b sznvd 4c twx0swi7 z2qiz-h61 -t82p17ohyz holozoic nutrition.

2.Describe how herbivores are adapted to eating plants.

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