Crabs, earthworms, mites and snails feed +zhw1hfs, 0tuh,8 (quapdl )uon the remains of dead plants and animals. What type of organisms are8 wp,)h (dlq,0utasuzhh 1+fu these?

  Which of the following is not a sapnjh7i ,phbi bt-l)a. 8rotroph?

  Some fungi obtain nutrients by releasing digestive enzymes into tt + zrut5cag/1heir surroundinc gtr /a+1tu5zgs. The 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 a rice cultivation system that eliminates the neey-u7 o6u:f wv7gah4 1juxcj0 pd 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-7u47jhjg6ucvp0 xw:yufa1 o 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 gimid)0 0wdt mkw )u;lzy+ 5fe+pves the correct information about the different types of+)+ 5) imuw0 ;f wdtlydezmp0k organisms.

  A student set up an aquatic mesocosmjb:fnw1m ,(py using a commercially available seawater-filled glass orb, which included algae, shrimp, some corals and gravj:f,b(w npym1 el. 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/are true for hovta.n(j/t4kce c w/d, lozoic 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 hetero7lhpv1 ir0a 9tqi0sz4trophic?

  What are incisors us-c)sx6 r gtaf m7/na)med for?

The image below represents the skull of a gorilla, chimpanzee, and hur-+8,3l6e/vhpngn m j;ajedm man.

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 extracelluo+(5 al+1 jz(isuaiyt 1an- 8mntnl* zlar secretion of digestive enzymes and absorption of the breakdown products.oin llyi 11a tu+s +5-jzma(*ta n8(nz Which statement describes the nutritional mode of this organism?

  Zooxanthellae are algae4k* r jegn,,w/blevzdt(l:j jqhp-3: that live inside coral. Corals feed on the carbon compounds produced byp,l/ v:w4k, r :ezbehj3(l-tnj* j dqg zooxanthellae 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 simulate conditaewfvhx(9ob3zp;q+ wss 0+vo *+i)rnions 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 s 9qi+ wp;wvr3x+s+ab o )f0hszo(*v enmall 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 9w,z*9vx0icm 9*q :fqtuhgac some fish. The fish would be predators of the pond and feed on the zooplankton (prey) growing in the pond. Zoo :f*czvq gu09, *hia9mtqwxc9plankton 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 proce7g:zfv3 wvi+b9, jppon 9/h dp4 teg)jss by which detritivores and 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 differ dsbr1, g3zyy4-hz,g lences 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.