IB Biology Review Ecology: Chapter 50 What do you remember

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IB Biology Review

• Ecology Chapter 50

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What do you remember from the Wissahickon Creek
trips?

• Eutrophication
• Biodiversity
• Invasive Species
• Benthic Macroinvertebrates

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Simpsons Biodiversity Index

• 1 - D (the greater the , the greater the
  biodiversity)
• D n(n-1)
• N(N-1)
• Where n total of organisms of a particular
  species
• N total of organisms of all species

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What is eutrophication?

• When too much algae grows because of an addition
  of nutrients to the water
• What happens to a eutrophied ecosytem?
• The oxygen-sensitive species die because
• 1) The excess algae uses oxygen during
  respiration, so they use up the oxygen
• 2) When the algae dies, bacteria use oxygen to
  break it down

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MC-1. Introduced or invasive species

• A. usually out-compete the native species for
  available resources
• B. often become extremely common as they
  colonize an area
• C. can disrupt the balance of the natural
  species with which they have become
  associated
• D. B and C only
• E. A, B, and C are correct
• Correct answer E

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MC-2. Biological control of an invasive species
of a plant would include

• A. chemical pesticides
• B. fungicides
• C. a fungal disease
• D. a machete
• E. fire
• Correct answer C

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What issue does the treatment and prevention of
invasive species bring up?

• Precautionary Principle
• A guiding principle which holds that, if that
  effects of a human-induced change would be very
  large, those responsible for the change must
  prove that it will not do harm before proceeding.
  
• Or better safe than sorry
• How does the Precautionary Principle give
  justification for strong action against the
  threat posed by the Greenhouse Effect?
• Were not sure if humans are causing global
  warming, but just incase, we better reduce the
  Greenhouse Effect!

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MC-3. You are working for the Environmental
Protection Agency and researching the effect of a
potentially toxic chemical in drinking water.
There is no documented scientific evidence
showing the chemical is toxic, but many suspect
it to be a health hazard. Using the precautionary
principle, what would be a reasonable
environmental policy?

• A. Establish no regulations until there are
  conclusive scientific studies.
• B. Set the acceptable levels of the chemical
  conservatively low, and keep them there
  unless future studies show that they can
  safely be raised.
• C. Set the acceptable levels at the highest
  levels encountered, and keep them there
  unless future studies demonstrate negative
  health effects.
• D. Caution individuals to use their own judgment
  in deciding whether to drink water from a
  potentially contaminated source.
• E. Establish a contingency fund to handle
  insurance claims in the event that the
  chemical turns out to produce negative health
  effects.
• Correct answer B

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1. Habitat2. Ecology 3. Abiotic4.
Biotic5. Species6. Population7. Population
Ecology8. Community9. Community
Ecology10. Ecosystem11. Ecosystem
Ecology12. Biome13. Biosphere14.
Producer15. Consumer

• A. Living organisms (called biota)
• B. Concentrates mainly on factors that affect how
  many individuals of a particular species
  live in an area.
• C. The global ecosystemthe sum of all the
  planets ecosystems. This broadest area of
  ecology includes the entire portion of Earth
  inhabited by life the atmosphere to
  an altitude of several kilometers, the land down
  to and including water bearing rocks at
  least 3 kilometers belowground lakes and
  streams, caves, and the oceans to a depth of
  several kilometers.
• D. The study of relationships between living
  organisms and between organisms and their
  environment.
• E. A group of organisms of the same species who
  live in the same area at the same time.
• F. The environment in which a species normally
  lives or the location of a living organism.
• G. Non-living (ex. temp, light, water, nutrients)
• H. A group of populations living and interacting
  with each other in an area.
• I. Any of the worlds major ecosystems,
  classified according to the predominant
  vegetation and characterized by adaptations of
  organisms to that environment.
• J. A community and its abiotic factors.
• K. Deals with the whole array of interacting
  species in a community. This area of
  research focuses on how interactions such as
  predation, competition, and disease, as
  well as abiotic factors such as disturbance,
  affect community structure and organization.
• L. A group of organisms that can interbreed and
  produce fertile offspring.
• M. The emphasis is on energy flow and chemical
  cycling among the various biotic and
  abiotic components.
• N. An organism that obtains its energy directly
  from sunlight or chemical energy.
• O. And organisms that ingest other organic matter
  that is living or recently killed

Answers 1-F, 2-D, 3-G, 4-A, 5-L, 6- E,
7-B, 8-H, 9-K, 10-J, 11-M, 12-I, 13-C,
14-N, 15-O
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MC-4. Which of the following levels of
organization is arranged in the correct sequence
from most to least inclusive? (Inclusive means
that is contains more different types of
organisms.)

• A. community, ecosystem, individual, population
• B. ecosystem, community, population, individual
• C. population, ecosystem, individual, community
• D. individual, population, community, ecosystem
• E. individual, community, population, ecosystem
• Correct answer B

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MC-5. A population is correctly defined as
having which of the following
characteristics? I. inhabiting the same
general area II. individuals belonging to the
same species III. possessing a constant and
uniform density and dispersion

• A. I only
• B. III only
• C. I and II only
• D. II and III only
• E. I, II, and III
• Correct answer C

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MC-6. Probably the most important factor(s)
affecting the distribution of biomes is/are

• A. wind and water current patterns
• B. species diversity
• C. community succession
• D. climate
• E. day length and rainfall
• Correct answer E

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What are the biomes?
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The moisture and temperature on the biomes chart
are examples of what ecological device/term (in
the vocab)? Name a few others.

• Abiotic factors
• Light, soil pH, mineral nutrients in the soil,
  breeding sites, territory, wind, water currents
• What are the opposite of abiotic factors? Name
  a few.
• Biotic factors.
• Predation, competition, population density, food
  supply, waste pollution, disease

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MC-7. Important abiotic factors in ecosystems
include which of the following?

• A. temperature
• B. water
• C. wind
• D. A and C only
• E. A, B, and C
• Correct answer E

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MC-8. Which of the following are important biotic
factors that can affect the structure and
organization of biological communities?

• A. precipitation, wind
• B. nutrient availability, soil pH
• C. predation, competition
• D. temperature, water
• E. light intensity, population density
• Correct answer C

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1. Outline the consequences of releasing excess
fertilizer or raw sewage into a river or
stream. (6 marks)
IB Exam Question

• Causes eutrophication of water which is
  overfertilization
• These excess nutrients increase algal/plant
  growth
• This leads to the death of excess algae/plants
• Then bacteria decompose of algae/plants
• This causes an increase in decomposer bacteria
• These bacteria use up all the oxygen and
  deoxygenate the water
• This results in a decrease in population of
  oxygen sensitive species, thereby lowering the
  aquatic biodiversity

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2. Temperature is an abiotic factor affecting
distribution of plant species in some areas.
State three other abiotic factors that affect
the distribution of plant species.
(3 marks)
IB Exam Question

• water/moisture
• light
• mineral nutrients in soil
• soil pH

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3. Explain why it is useful to use benthic
macroinvertebrates populations to estimate the
water quality of a body of water.
(3 marks)
IB Exam Question

• Chemical data only relevant to the time period
  sample was taken
• Benthic macroinvertebrates respond to cumulative
  effects of chemicals, oxygen levels, etc.
• Chemical data does not reveal effect of
  pollutants on ecosystem. Benthic
  macroinvertebrates do sensitive organisms
  respond to pollution first, then moderately
  sensitive, then less sensitive

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4. Explain the factors that affect the
distribution of terrestrial (land) animal
species. (5 marks)
IB Exam Question

• breeding sites animals must breed and may need
  a special site
• food supply may feed on specific foods /
  abundance
• territory need to establish / defend for
  food/mates
• predation can reduce the range of another
  species / be reduced by predation
• temperature/climate need the proper range for
  survival
• water need water to live in (aquatic) / proper
  amount for bodily functions
• free of pollution/toxic substances - could cause
  death

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

• Light is the initial source of energy for almost
  all communities
• Plants absorb light and use it in photosynthesis
• Plants produce food/ organic matter for
  consumers
• Plants produce oxygen which is need for cell
  respiration by many organisms
• Plants are the main producers in most
  communities
• Energy flows along food chains/ webs from plants
• First order consumers eat plants/ producers
• Second order consumers eat first consumers that
  have eaten plants/ producers