Download Populations, Communities and Species Interaction

Study Questions: Populations, Communities Species
Interaction
1. Define the terms herbivore, carnivore and omnivore; explain the
terms primary vs. secondary produces, giving examples of each.
Populations, Communities and Species
Interaction
2. Define the term species and explain what determines where a
species lives.
Ecology: study of relationships
3. Explain evolution, using terms such as adaptation, natural
selection, selective pressure and mutation.
betweens organisms and
4. How and why might new species come into being?
5. Compare and contrast predation, parasitism, competition, and
symbiosis (including mutualism and commensalism)
6. Discuss ideal vs. actual population growth; compare and contrast
r- and k-reproductive strategies.
their environment
Ecosystem: biological community
and its environment
7. Describe and define a community, including diversity and
abundance, and succession.
Herbivore:
organism that eats plant matter
Primary producers: organisms that do photosynthesis
6H2O + 6CO2 + sunlight Æ C6H12O6 (sugar) + 6O2
Carnivore: organism that eats animal matter
Pix of plant, algae
Omnivore:
organism that eats plant and animal
matter
Consumers: organisms that do not do photosynthesis,
but obtain their nutrients by eating
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Food Chains and Food Webs: interactions and
connections between organisms that transfer
organic matter via eating
Trophic level: an organism’s feeding status; its
place in the food chain
Species: genetically similar organisms that can
successfully reproduce with each other
Range of Tolerance
What Determines Where Species Live?
Upper limit
of tolerance
Lower limit
of tolerance
Factors such as temperature, nutrient supply, etc.
Few
organisms
Abundance of organisms
Few
organisms
No
organisms
Population size
Tolerance limits: minimum and maximum levels of
factors beyond which organisms cannot survive
No
organisms
Zone of
Zone of
intolerance physiological stress
Low
Optimum range
Temperature
Zone of
Zone of
physiological stress intolerance
High
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Adaptation: changes that allow an organism or
population to survive in its environment
Selective pressures and random mutations lead to
Natural selection: the process in which better
competitors reproduce more successfully
Some of these changes are passed on genetically
Evolution: gradual changes in species that result
from competition for scarce resources
Speciation: the development of a new, distinct species
4 of the 13 Galapagos Finch Varieties
Speciation can occur as a result of:
• New food or other resource
• New stress (climate or predator)
• Geographic isolation
• Behavioral isolation
Species Interactions
• Predation
Co-evolution: predator and prey evolve in response
to each other (camouflage, mimicry)
Predator: organism that feeds directly upon another
living organism (prey)
American bittern
Scorpion Fish
Predator can affect population of prey
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Monarch
Viceroy
• Competition
Organisms compete for:
Nutrients, space, mates, etc.
Longhorn Beetle
• Symbiosis: 2 or more species living together
Intra- and inter-specific competition exist
Mutualism: both members benefit
Commensalism: 1 species benefits, 1 is neutral
Parasitism: 1 species benefits, 1 is harmed
Population Dynamics
Population: all members of a species that live in the
same area at the same time
Population growth depends on many factors
• Size of population
• Resource availability
• Predator populations
• Environmental conditions
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Ideal, unlimited population growth is exponential
Actual growth slows down as resources become limited
Reproductive Strategies
r-adapted species: use rapid, copious reproduction
K-adapted species: slower reproduction, fewer offspring
J curve
S curve
Communities
Community: all the populations that live and interact
in an area
Ecotones: boundaries between adjacent communities
Diversity: number of different species within an area
Abundance: number of individuals of a species within
an area
The greater diversity in a community, the greater
resiliency and stability of that community
Primary succession: development of a community
where none has previously existed
Secondary succession: development of a
community where a pre-existing community was
disrupted or destroyed
Climax community: stable community with no
further succession; “mature” community
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Invasive species: organisms not normally found in a
particular location that disrupt the local community
Hawaiian mongoose
Polynesian rat
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