5.1 Communities and Ecosystems WORD

Student Name: Due Date: 18/11/2010 Essential Biology 5.1: Ecosystems

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Blog resource: http://tinyurl.com/249fd5a

Cite all sources using the CSE method (or ISO 690 Numerical in Word). The first example has been done for you.

Complete the self-assessment rubric before submitting to Moodle. Avoid printing this if pos-sible.

1. Define the following terms:

Species: A group of organisms that can interbreed to produce fertile off-spring. (1)

Habitat- The environment in which a species normally lives (the location of a living organism)

Population - a group of organisms of the same species living in the same area at the same time

Community- a group of populations living and interacting with each other in an area

Ecosystem- a community and its abiotic environment (non-living)

Ecology- the study of relationships between living organisms and between or-ganisms and their environment

Niche - the status of an organism within its environment and community in-cluding diet, where they live and when they are active.

Biodiversity- a variation (number and variety of species) of life forms within an ecosystem

Trophic level-the position an organism or a group of organisms occupy on the food chain determined by the number of energy steps to get to that level.

2. Complete the tree below with definitions and examples of each type of feed-ing strategy.

Distinguish between the feeding strategies at each level of the diagram.

Heterotrophs feed off of others while autotrophs feed themselves. The two types of autotrophs feed by photosynthesis (sun energy) and chemosynthe-sis(chemical energy). Heterotrophs have decomposers (energy from non-liv-ing organisms) and consumers (energy from living or recently killed).

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3. Food chains represent the flow of energy and nutrients in a series of feeding

relationships.

Give one example of a marine food chain (min. 4 organisms)

Osprey --> bream --> freshwater shrimp --> phytoplankton

Give one example of a terrestrial food chain (min. 4 organisms)

Sparrow hawk --> great tit --> moth caterpillar --> yellow iris

Give one other example of a food chain (min. 4 organisms)

Seal --> cod --> krill, amphipods --> diatoms

4. Describe what is meant by a food web.


Organisms which produce their own food from organic methods

Producers

Organisms which derive energy from other living organisms

Photosynthesis, green plants, pytoplankton and algae

Chemosynthesis, deep sea, chemosynthetic bacteria

Decomposers

Organic matter which is living or recently killed

Herbivores, eat producers Carnivores,omnivores, eat other consumers

Ingests non-living organic matter,

earthworms, woodlice

Lives in or on non-living organic matter, secreting digestive enzymes into it and absorbing digestive

products, bacteria and fungi




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A food web shows all of the feeding relationships within a habitat and contain many food chains.

5. The food web below shows some coral reef feeding relationships;

a. Identify species in the following trophic levels:

i. Producers

Phytoplankton and algae

ii. Primary consumers

Sea-whip, parrotfish, turtles, marine invertebrates,marine omnivores

iii. Secondary consumers

Reef sharks, snappers, groupers

6. On a separate sheet, construct a freshwater food web based on the following information:

Organism Energy sourcesWater crowfoot Sunlight Cased caddisfly larva

Micro-plants, algae, particles of dead plants and animals

Damselfly nymph Micro-plants, algae, particles of dead plants and animalsMayfly nymph Micro-plants, algae, particles of dead plants and animalsDragonfly Other adult insects and small fliesDuck All nymphs, all plants, snails, tadpoles, young frogsFreshwater Shrimp Particles of dead plants and animals





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Water vole Plants Algae SunlightOtter Fish, frogs and newtsWater starwort SunlightPond snail Microplants, all water plants and algaeAlderfly nymph Micro-plants, algae, particles of dead plants and animalsPond skater Particles of dead plants and animalsFrog Mayfly, midge larvae, pond skater, caddisfly, small fliesTadpole Micro-plants, algaeMicro-plants SunlightGreat diving beetle Water flea, snails, tadpole, all nymphsBullhead fish Diving beetle, tadpole, all nymphs, water flea, snail, midge lar-

vaeAdapted from: http://www.cornwallriversproject.org.uk/education/education_pack.htm

7. For the food web created above:

a. Identify organisms in each of the trophic levels.

Producer- micro-plant, algae, water starwort, water crowfoot

Primary Consumer- Tadpole, Alderfly nymph, pond snail, mayfly nymph, cased cad-disfly larva, damselfly nymph, water vole

Secondary Consumers- Bullhead fish, great diving beetle, frog, duck, dragonfly

Tertiary Consumers- otter

Decomposers- pond skater, freshwater shrimp

b. Identify organisms that fit more than one trophic level.

A duck could fit on more than one trophic level because it eats the insects as the secondary consumers do, but also eats frogs so it could be even with the otter

c. Identify those which could be classed as detritivores

Detritivores would be considered pond skaters and freshwater shrimp as they feed off of dead animals.

8. Suggest why it is sometimes difficult to classify organisms into trophic levels.




http://www.cornwallriversproject.org.uk/education/education_pack.htm


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It is rare that all organisms eat one thing, the only organism that can be classified into a proper trophic level is the producer as it creates for itself.

9. Outline why numbers of organisms are smaller at higher trophic levels.

There are less predators because there is less energy at the top of the trophic levels and also there

10.State the original source of energy for almost all communities.

The initial energy source for almost all communities is sunlight.

11.Explain how energy flows through a community, including why energy trans-fers are never 100% efficient.

90% of energy is lost due to it not being ingested, not digested or assimilated, ex-creted, or lost as heat from respiration.

12.State the function of a pyramid of energy.

Pyramids of energy show the flow of energy between trophic levels.

13.Give an example of a unit of measurement used in a pyramid of energy, giv-ing a description of each component.

The unit of measurement used is units of energy per unit area per unit time (kj m-2 y -1 ).

14.“Energy flows through an ecosystem, nutrients are recycled.”

Explain this statement with the aid of a flow chart. Include the roles of saprotrophic bacteria and fungi.





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15.Outline three examples of cycles of inorganic nutrients. For each, outline the uses of the nutrients in living organisms, its method of transfer into and through the food chain and how it is returned to the inorganic nutrient pool.

a. Carbon

Uses: forming the long molecular chains of DNA

Food chain: Carbon is introduced to the food train through producers via photosynthesis and is then carried on through each trophic layer by the predators eating the producers. It is then returned to the inorganic nutrient pool when the highest trophic layer dies and the saprotrophic bacteria and fungi decompose the deceased and return the carbon back.

b. Nitrogen

Uses: Makes explosives and laughing gas

Food chain: Nitrogen is introduced to the food chain through the amino acids/proteins in our bodies and are also very important in a plants nutrition. The nitrogen is passed on through each trophic layer and then when the highest predator in that specific food chain dies, de-composers such as worms decompose the dead predator and allow the nitrogen to enter back into the air.

c. Calcium

Uses: keeps bones and skeletons strong and teeth as well, also makes strong shells of birds and the cell wall of plants.

Food chain: introduced to the food chain through plants as well and passed up through the trophic levels providing less calcium for each level. When the animal dies, the calcium is passed onto the decomposers who then continue the cycle when they become the prey.




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5.1 Communities and Ecosystems WORD