Crabs, earthworms, mites and snails feed on the mo0;ze4ta b-n remains of dead plants and animals. What type of organisms are these?azn0 om-;b4et

  Which of the following is dwjx g/9p*o3e e/;hme not a saprotroph?

  Some fungi obtain nutrients by releasing digestiv;mnicx k;g)k;i44lzj8f :ged e enzymes into their surroundings. The enzymes break down things such as dead and decaying leaves and the fungi then absorb the products. Which of these terms best describe 4:ecgj4;m zdfil8;kg; x nik)s these fungi?

  The illustration shows a rice cultivation syr+ad o5p(a yg+ew vsh3*m,+gwstem that eliminates the need for fertilizers, herbicides and pesticides by using ducks in the organic cultivation (w ehrpy3 wm, a*o sggda+5+v+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 table which gives tsv5 y(g27 pg+uecdq7p he correct information about the different types of org eg 7pd5q+cp7(v2yug sanisms.

  A student set up an aquatic mesocosm using a commercially available seawat:x 11,jm(awn b,qx +9 5pqsgjp9ylui eer-filled glass orb, which included algae, shrimp, some corals and gravel. The q1pj 9sypu, e:1iq,lx9anx+m j bgw5(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 f5i5syofzh/ sragi3*/+) z w npor holozoic 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 het s l 1 z9upxmv,3er:kn10tokk5erotrophic?

  What are incisors used fo4tay yoigo mq63/6;c ir?

The image below represents the skull of a gorilla, chimlx 6i z4c5ouem5*x/i ppanzee, 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 extra*x/sk/lpu /4 v qvc3rrcellular secretion of digestive enzymes and absorption of the breakdown products. Which statement describes thekrv lx/3 q 4us/rc*/pv nutritional mode of this organism?

  Zooxanthellae are algae that liverjn;bzbwvf22 vf4oy)zph3*b9y2 fp(p;wh d 1 inside coral. Corals feed on the carbon compounds produced by zooxanthellae from carbon dioxide, water, and sunlight. Which describespy p bzvbj2 hfy9w2wbz13;4dn*f; vr(o )hpf2 the nutrition of these organisms?

  A student wants to set up an aquatic mesocosm xwg s 1 tc;dovrim: x(-+mfk4,using seawater to simulate conditions in the food web (showns-tro;c gx4:vmk wx1 ,imdf+ ( in the image below) 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 smnp9/5 3c xf)tjouw ;twall pond in the backyard and wanted 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 phytoplankton or algae for their supply of nox9; 3cjww ptu)f/5t 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 processk w/zo d1xjlys)k8 ;)t 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 differences between mixotrophic and holozoic n /u:r e:q dqicjcsu-,56d gp3yutrition.

2.Describe how herbivores are adapted to eating plants.

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