Crabs, earthworms, mites and snails feed on the remains ofv4rg,.c n tbr, dead plants and animals. What type of organbn,,c4 rrg tv.isms are these?

  Which of the following is 2 co6iegc /w1v5 dgb:+ )wgbjpnot a saprotroph?

  Some fungi obtain nutrients by releasing digesti/ecr; :v8pmuc8 mp,xf ve enzymes into their surroundings. The enzymes break down things such as dead and decaying leaves and the funcpmfpx vu ; :8m8ce,r/gi then absorb the products. Which of these terms best describes these fungi?

  The illustration shows a rice cultivation system ts bo8pfoib 43z. ylgccir342 -2axpa+hat eliminates the need for fertilizers, herbicides and pesticides by using ducks in the organic cult+yz823pipi abxccrsf2-4a 4 o3blo .g ivation 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 consumption in one location.

  Identify the row in the tabcqgzua 9:; t-(ksahmq. h6 7ufle which gives the correct information about the different ty:kqhf; z6qha m t-(9ua.s gc7upes of organisms.

  A student set up an aquatic mesocosm using a commercuy hq6c1q mkn,6 vodg75t7h.dially available seawater-filled glass orb, which included algae, shrimp, some corals and gravel. The student placed it near a window to provide a light source. Which of the following statemendtk 57h.m h, uogn71d6 cqvyq6ts 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 hol iq, k*mg9d+hu5q; ftqozoic nutrition?
I. Demonstrated by saprotrophs
II. Involves complete or partial ingestion
III. Food is digested internally

  Which term refers to organisms that are both autotw2 tqa+i.6 a; dir6i)akaa+3(asz csmrophic and heterotrophic?

  What are incisors usetnjgw:ws1-/sd:hi/ xd for?

The image below represents the skull of a gorilla, chimpanzee, 70myjkf,d; ke 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 extracellular2t d4ned sat/; secretion of digestive enzymes and absorption of the breakdown products. Which statement describes the t ;sdt42adne /nutritional mode of this organism?

  Zooxanthellae are algae that live i)vq8 j40vlz zwnside coral. Corals feed on the carbon compounds produced by zooxanthellae from carbon dioxide, water, and sunlight. Which describes the nutrition of )z4vqzjw0 8l vthese organisms?

  A student wants to set up an aquatic0o;z huduf2/*fb8 wx o mesocosm using seawater to simulate conditions in the food web (shown in the image below) and test its stability. He used seawater and sa/ w b2oz;*0uou dx8hffnd 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 inxcasj5f(c/g f) gyj .lf9k 5s) the backyard and wanted to add some fish. The fish would be predators of the pond and feed on the zooplankton (prey) growing in th a5 )) sfccl5.kgjx /gfj(s9fye 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 detritivorv( +vlyb9h x*oes 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 differences betwesn z w3/vzbu.2en 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.