E Ecology Organizer (Topic 5 and Option G)

eEcology Organizer (Topic 5 and Option G)

Vocabulary

Term / Definition / Examples
Species
Habitat
Population
Community
Ecosystem
Ecology
Autotroph / Synonym:
Heterotroph / Synonym:
Food Chain
Food Web
Decomposer
Detritivore
Saprotroph
Trophic Level
Greenhouse Effect
Global Warming
Climate Change
Precautionary Principle
Natality
Mortality
Emigration
Immigration
Biotic Factors
Abiotic Factors
pH
Enzyme
Breeding
Territory
Quadrat
Transect
Niche / Niche:
Fundamental Niche:
Realized Niche:
Competition
Competitive Exclusion
Herbivory
Predation
Parasitism
Host
Exoparasites
Endoparasites
Mutualism
Biomass
Primary Production / Production:
Gross Production:
Net Production:
Succession / Succession:
Primary Succession:
Secondary Succession:
Climax Community
Biosphere
Biome
Biodiversity
Invasive / Invasive Species:
Deliberate Introduction:
Accidental Introduction:
Biological Control
Biomagnification
Ozone Layer
Indicator Species
Extinction
Nature Reserve
Edge Effects
Wildlife Corridors
Restoration
Conservation / Conservation:
In Situ Conservation:
Ex Situ Conservation:
Captive Breeding
Botanic Garden
Seed Bank
Landrace
r-Strategy
K-Strategies
Maximum Sustainable Yield
Carrying Capacity

5.1.1 Define species, habitat, population, community, ecosystem and ecology.

Place the terms population, community and ecosystem into the individual circles to express their relationship. Explain how you chose to place them.

The term species is defined as a potentially interbreeding population having a common gene pool and producing fertile young. Outline why this definition cannot be applied to all living organisms.

......

(Total 4 marks)

Use the terms population, community and ecosystem to describe all components of this picture.

Apply one or more of the terms that follow to describe each of the listed features of a freshwater lake: population, ecosystem, habitat, abiotic factor, community and biomass.

· The whole lake

· All the frogs of the lake

· The flow of water through the lake

· All the plants and animals present

· The total mass of vegetation growing in the lake

· The mud of the lake

· The temperature variations in the lake

What term refers to a community and its abiotic environment?

A. Biosphere

B. Ecosystem

C. Habitat

D. Niche

In communities, groups of populations live together and interact with each other. Outline the importance of plants to populations of other organisms in a community.

(Total 6 marks)

5.1.2 Distinguish between autotroph and heterotroph.

Energy Source / Trophic Level / Synonym / Organic Molecule Origin? / Example
Autotroph
Heterotroph

Outline why the transparency of water is important to organisms living in an aquatic habitat.

......

5.1.3 Distinguish between consumers, detritivores and saprotrophs.

Shark vs. Mold
/ Crab vs. Shark
/ Mold vs. Crab

Similarities
Differences

Which organisms externally digest dead organic matter and then absorb the nutrients?

A. Autotrophs

B. Detritivores

C. Heterotrophs

D. Saprotrophs

5.1.4 Describe what is meant by a food chain, giving three examples, each with at least three linkages (four organisms). Note: Each food chain should include a producer and consumers, but not decomposers. Named organisms at either species or genus level should be used. Common species names can be used instead of binomial names. General names such as “tree” or “fish” should not be used.

Palm roots Mouse Lizard Sun Bear

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

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

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

What do the arrows represent in a food chain?

5.1.5 Describe what is meant by a food web.

How are these food web examples organized? Explain.

5.1.6 Define trophic level.

Label: Primary consumers, Carnivores, Producers, Apex Predators, Herbivores, Tertiary Consumers, Secondary Consumers.

Highlight: Heterotrophs (yellow), Autotrophs (green)

Outline: Carnivores of carnivores (red), carnivores of herbivores (orange), Apex Predators (brown)

5.1.7 Deduce the trophic level of organisms in a food chain and a food web.

Identify the trophic level for each of the organisms in the food web you created on the previous page.

The diagram below is a simplified version of a food web from Chesapeake Bay. The arrows indicate the direction of energy flow and the numbers indicate species within the food web.

At which trophic level or levels does species II function?

A. 2nd and 3rd consumer

B. 3rd consumer

C. 3rd and 4th consumer

D. Producer

Which of the species feed both as secondary consumers and as tertiary consumers?

A. I, II and IV only

B. I, III and V only

C. I, IV and V only

D. III, IV and V only

5.1.8 Construct a food web containing up to 10 organisms, using appropriate information.

Activity: Place the following organisms into a food web below:

a) Anchovies

b) Herring

c) Rockfish

d) Squid

e) Dolphin

f) Puffer

g) Phytoplankton

h) Salmon

i) Octopus

j) Porpoise

k) Tuna

l) Shark

m) Sea Lion

n) Seal

o) Sardines

p) Lancet

q) Mackerel

r) Jellyfish

s) Barnacles

t) Shrimp

u) Hake

v) Krill

w) Zooplankton

5.1.9 State that light is the initial energy source for almost all communities.

Explain how all of the energy transferred in the food chains of 5.1.4 originates from the Sun.

5.1.10 Explain the energy flow in a food chain.

5.11 State that energy transformations are never 100% efficient.

The arrow shows a flow of energy.

An arrow diverging from the pathway represents lost energy

The width of the arrow represents the proportion of energy remaining or lost.

List the three ways energy is lost when moving from one trophic level to the next.

Show the Sankey diagram for energy transformations on pg. 103 of Walpole and explain it.

Show the linear food chain diagram involving energy flow on pg. 144 of Clegg and explain it.

The energy flow diagram below for a temperate ecosystem has been divided into two parts. One part shows autotrophic use of energy and the other shows the heterotrophic use of energy. All values are kJm–2 yr–1.

(a) Calculate the net production of the autotrophs.

......

(1)

(b) (i) Compare the percentage of heat lost through respiration by the autotrophs with the heterotrophs.

......

(1)

(ii) Most of the heterotrophs are animals. Suggest one reason for the difference in heat losses between the autotrophs and animal heterotrophs.

......

(1)

The heterotrophic community can be divided into food webs based upon decomposers and food webs based upon herbivores. It has been shown that of the energy consumed by the heterotrophs, 99% is consumed by the decomposer food webs.

......

...... (1)

(d) Deduce the long-term effects of sustained pollution which kills decomposers on autotrophic productivity.

......

(2) (Total 6 marks)

5.1.12 Explain reasons for the shape of pyramids of energy.

Draw the 2 pyramids of energy on pg. 104 of Walpole and explain each.

Draw the 2 pyramids of energy on pg. 42 of the Allott study guide and explain each.

Draw the 4 pyramids of energy on pg. 145-146 of Clegg and explain each.

Draw the pyramid of energy on pg. 170 of Allott and explain it.

The total solar energy received by a grassland is 5 × l05 kJ m–2 y–1. The net production of the grassland is 5 × 102 kJ m–2 y–1 and its gross production is 6 × l02 kJ m–2 y–1. The total energy passed on to primary consumers is 60 kJ m–2 y–1. Only 10% of this energy is passed on to the secondary consumers.

(a) Calculate the energy lost by plant respiration.

......

...... (2)

(b) Construct a pyramid of energy for this grassland.

(3) (Total 5 marks)

The diagram below represents an energy pyramid and four trophic levels.

[Source: adapted from www.bio.miami.edu/dana/160/pyramid.gif]

(i) Identify the trophic level of the organisms indicated below.

I......

IV......

(2)

(ii) Calculate the approximate amount of energy in kilojoules transferred in m–2 yr–1 from trophic level I to trophic level II.

...... kJ

The diagram below represents a pyramid of energy for a community of organisms. State what the bars labelled I and II indicate.

I......

II......

5.1.13 Explain that energy enters and leaves ecosystems, but nutrients must be recycled.

5.1.14 State that saprotrophic bacteria and fungi (decomposers) recycle nutrients.

Show the food chain as a pyramid of biomass involving energy flow on pg. 144 of Clegg and explain it.

5.2.1 Draw and label a diagram of the carbon cycle to show the processes involved.

Copy the diagram from pg. 106 of Walpole.

CO2 Sources / Processes that add CO2 / CO2 Sinks / Processes that remove CO2

The diagram below shows a simplified version of the carbon cycle.

What processes are involved in the transfer of carbon at stages I and II?

I / II
A. / combustion / photosynthesis
B. / photosynthesis / respiration
C. / combustion / respiration
D. / fossilization / respiration

Outline ways in which leaves take part in the carbon cycle in ecosystems, apart from photosynthesis.

(Total 4 marks)

The diagram below is part of a carbon cycle diagram for an ecosystem in a pond.

(a) State the names of the processes that

(i) convert carbon dioxide into organic compounds in pond weeds and algae

......

(1)

(ii) convert organic compounds in pond weeds, algae and primary consumers into carbon dioxide.

......

(1)

(b) (i) Draw arrows on the diagram above to show how the saprotrophs obtain carbon.

(1)

(ii) Explain the role of saprotrophs in recycling carbon.

......

(2)

(c) Draw a box on the diagram in an appropriate position, labelled organic compounds in secondary consumers. Draw arrows to show the links between secondary consumers and other parts of the carbon cycle.

(2)

There has been a significant increase in the concentration of carbon dioxide in the Earth’s atmosphere during the last fifty years.

(d) (i) Suggest two reasons for this increase in atmospheric carbon dioxide concentration.

1......

......

2......

......

(2)

(ii) Suggest one effect of an increase in carbon dioxide concentration on organisms in a pond. Include in your answer the reason for the effect and the type of organisms that are affected.

......

(2) (Total 11 marks)

5.2.2 Analyze the changes in concentration of atmospheric carbon dioxide using historical records. Note: Data from the Mauna Loa, Hawaii, or Cape Grim, Tasmania, monitoring stations may be used.

Create a simplified version of ice core graph from pg. 149 of Clegg. Explain it in your own words.

5.2.3 Explain the relationship between rises in concentrations of atmospheric carbon dioxide, methane and oxides of nitrogen and the enhanced greenhouse effect. Note: Students should be aware that the greenhouse effect is a natural phenomenon. Reference should be made to transmission of incoming shorter-wave radiation and re-radiated longer-wave radiation. Knowledge that other gases, including methane and oxides of nitrogen, are greenhouse gases is expected.

CAUSE / EFFECT
Fossil Fuel Use
Increased Greenhouse Gas Concentration
Re-radiation

What is a factor that increases the greenhouse effect and what is a consequence of it?

Factor contributing to increases in the greenhouse effect / Consequence of the increased
greenhouse effect
A. / Increasing global temperatures / Rising sea levels
B. / Rising sea levels / Increasing global temperatures
C. / Increasing global temperatures / Burning fossil fuels to run air conditioning
D. / Increases in air travel / Increasing global temperatures

The graph below shows the variation in the concentration of atmospheric carbon dioxide since 1970.

The annual fluctuation is mainly the result of changes in the levels of photosynthesis associated with the seasons in Northern Hemisphere forests.

(a) (i) Describe the overall trend shown in the graph.

......

(1)

(ii) Suggest a cause for the overall trend throughout the period 1970–1999.

...... (1)

(b) (i) Using a clear label, identify any one point on the graph which shows the CO2 level in mid-summer. (1)

(ii) Explain why the concentration of CO2 varies with the seasons.

......

...... (2)

......

(1) (Total 6 marks)

5.2.4 Outline the precautionary principle. Note: The precautionary principle holds that, if the effects of a human-induced change would be very large, perhaps catastrophic, those responsible for the change must prove that it will not do harm before proceeding. This is the reverse of the normal situation, where those who are concerned about the change would have to prove that it will do harm in order to prevent such changes going ahead. TOK: Parallels could be drawn here between success in deterring crime by increasing the severity of the punishment or by increasing the chance of detection. If the possible consequences of rapid global warming are devastating enough, preventive measures are justified even if it is far from certain that rapid global warming will result from current human activities.

Consequences of Inaction / Potential Action To Be Taken
1. / 1.
2. / 2.
3. / 3.
4. / 4.
5. / 5.
6. / 6.

Use pg. 151 of Clegg for guidance.

According to the precautionary principle, what should happen if there are fears that eating a food might cause a health problem?

A. People should be warned about the possible health problem.

B. The company producing the food should be warned about the possible health problem.