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CHAPTER 50 OBJECTIVES
Explain why the field of ecology is a multidisciplinary science.
 Ecology is the scientific study of the interactions between organisms and their
environments. It involves using observations and experiments to test hypothetical
explanations of ecological phenomena. Examining questions from all areas of biology
as well as many physical sciences are all part of ecology.
Describe the relationship between ecology and evolution.
 Evolution can be described as a change in a population over time. Ecology has to do
with organisms and how they interact with their environment. The fact is when a
species adapts it can reproduce and continue evolving. There is also the fact that if
adapted to one environment and then placed in a foreign one, extinction may result.
Both sides affect evolution.
Explain the importance of temperature, water, light, soil, and wind to living organisms.
 Environmental temperature affects biological processes (metabolism) and body
temperature. Water is essential for life and adaptations for water balance and
conservation help determine a species' habitat range. Sunlight provides the energy
that drives nearly all ecosystems although only photosynthetic organisms use it
directly as an energy source. Wind amplifies the effects of temperature by increasing
heat loss by evaporation and convection. The composition of the substrate in a stream
or river greatly influences the water chemistry, which in turn influences the plants and
animals. The type of substrate influences what animals can attach or burrow in
intertidal zones.
Describe how environmental changes may produce behavioral, physiological,
morphological, or adaptive responses in organisms.
 PHYSIOLOGICAL: After several days to a few weeks the person responds with an
increased number of red blood cells being produced and when blood vessels in the
skin constrict within seconds to reduce loss of body heat when the skin is exposed to
very cold air. BEHAVIORAL: Migratory birds migrate to warmer climates to over
winter and Honeybees seal the hive during cold periods to conserve heat and cool the
hive on hot days by the collective beating of their wings. MORPHOLOGICAL:
Increase in coat fur or feather density in winter and change in coat color between
winter and summer.
Describe the characteristics of the major biomes: tropical forest, savanna, desert,
chaparral, temperate grassland, temperate forest, taiga, and tundra.
 I already know this.
Using a diagram, identify the various zones found in the marine environment.
 I already know this.
CHAPTER 52 OBJECTIVES
Define the scope of population ecology.
 Population Ecology is the study of the growth, abundance, and distribution of
populations (density and dispersion).
Distinguish between density and dispersion.
 Population density is the number of individuals per unit area. Population dispersion is
the pattern of how individuals within a population are spread out.
Explain how ecologists measure density of a species.
 Density = population (# of individuals) / area
Explain how age structure, generation time, and sex structure of populations can affect
population growth.
 These 3 factors all affect the population growth because some species all develop,
reproduce and die at the same age…there is no more generation time. But, we do
have generation time, which leads to more or less population. And the sex ratio, if we
have more females as well as males we will have a greater population of that specie.
But, if we have a low count of females or males, we will have a lesser population.
Describe the characteristics of populations, which exhibit Type I, Type II, and Type III
survivorship curves.
 Type I: species in which most individuals survive to middle age (humans).
 Type II: length of survivorship is random, like likelihood of death is the same at any
age (rodents).
 Type III: species in which most individuals die young, with only a relative few
surviving to reproductive age and beyond (oysters and other species that produce
free-swimming larvae that make up a component of marine plankton).
Explain how density-dependent factors affect population growth.
 Examples of density-dependent factors are resource depletion, competition, and
predation. These effects become more intense as the population density increases.
Describe how weather and climate can function as density-independent factors in
controlling population growth.
 Weather and climate function as density-independent factors because they affect the
population regardless of the density of the population.
Explain how density-dependent and density-independent factors may work together to
control a population's growth.
 Extreme climate may result in resource depletion making the population struggle to
survive.
List the three major characteristics of a life history and explain how each affects the: a.
Number of offspring produced by an individual b. Population's growth

Life history traits represent trade-offs between conflicting demands for limited time,
energy, and nutrients. These trade-offs often involve conflicts between current and
future reproductive output.
Explain how predation can affect life history through natural selection.
 Only the fittest can survive, so in order to survive any animal or plant must do
whatever is possible to live. This is where predators come about; they eat other plants
or animals to survive. But, at the same time they provide a balance in the
environment-no specie can overcome another specie.
Distinguish between r-selected populations and K-selected populations.
 R-selected populations colonize an area that is barren or uninhabited. They reproduce
quickly to ensure their survival. K-selected populations settle in a stabilized
environment. They tend to be large animals with long lifespan, so they produce few
offspring.
CHAPTER 53 OBJECTIVES
Explain the relationship between species richness, relative abundance, and diversity.
 The species diversity within a community would be the variety of species living close
enough together for potential interaction between the # of species (richness) and the
quantity of the species (abundance).
List four properties of a community, and explain the importance of each.
 Competitive exclusion principle: when two species compete for exactly the same
resource and one species is more likely to be successful. Resource partitioning: Species
that coexist in spite of apparent competition for the same resource (i.e. - frogs feeding on
different insects of the same pond). Character displacement: certain individuals may
obtain resources in their partitions (due to evolution two birds with the same beaks now
have slightly different beaks which allows them to find different food to survive).
Realized niche: that part of their existence where the niche overlap is absent and they
do not compete for the same species.
Explain how interspecific competition may affect community structure.
 Both population densities may increase (+ / +), one may increase while the other
decreases (+ /–), one may increase while the other is not affected (+ / 0), or both may
decrease (– / –).
Describe the competitive exclusion principle, and explain how competitive exclusion
may affect community structure.
 The principle states that 2 species cannot coexist in the same community if their
niches are the same. This may lead to extinction of the weaker competition or
adaptation of one species to a new niche; however it will not last long.
Distinguish between an organism's fundamental niche and realized niche.
 A fundamental niche is the resources a population is theoretically capable of using
under ideal circumstances. Biological constraints (competition, predation, resource
limitations) restrict organisms to their realized niche: the resources a population
actually uses.
Distinguish between Batesian mimicry and Mullerian mimicry.
 Batesian mimicry: occurs when an animal without any special defense mechanism mimics
the coloration of an animal that does possess a defense. Mullerian mimicry: occurs when
several animals, all with some special defense mechanism, share the same coloration
Explain the role of predators in community structure.
 A predator is an animal o plant that consumes another plant o animal. But, it’s good
we have predators for the simple reason that they provide balance in a community, so
no specie can overcome another specie.
Distinguish among parasitism, mutualism, and commensalism.
 Parasitism is a parasite that lives on or in a host taking nourishment from it but not
killing it immediately. Mutualisms co-evolve (both species benefit). Commensalism
is when one species benefits and the other is not affected.
Distinguish between primary succession and secondary succession.
 Primary Succession: no life then there is life
Secondary Succession: there is life, then no life, then it rebuilds
CHAPTER 54 OBJECTIVES
Explain the importance of autotrophic organisms with respect to energy flow and nutrient
cycling in ecosystems.
 Energy flow and chemical cycling are 2 interrelated processes that occur by the
transfer of substances through the feeding levels of ecosystems.
List and describe the importance of the four consumer levels found in an ecosystem.
 Producers: make their own food
Primary Consumers: eat producers
Secondary Consumers: eat producers and primary consumers
Tertiary Consumers: eat all of the above
Explain how gross primary productivity is allocated by the plants in an ecosystem.
 The total energy assimilated. This is the result of photosynthesis, the gross primary
productivity of most primary producers remains as net primary productivity after their
energetic needs are fulfilled.
Explain why productivity declines at each tropic level.

The amount of energy available to each trophic level is determine by the net primary
productivity and the efficiencies with which food energy is converted into biomass at
each link of the food chain.
Distinguish between energy pyramids and biomass pyramids.
 Energy pyramid, in which trophic levels are stacked in blocks, with primary
producers forming the foundation of the pyramid. Biomass pyramid, in which each
tier represents the standing crop biomass (the total dry weight of all organisms) in a
trophic level.
Describe the carbon cycle, and explain why it is said to result from the reciprocal
processes of photosynthesis and cellular respiration.
The carbon cycle is required for the building of all organic compounds.
 Reservoirs: atmosphere, fossil fuels, peat, durable, organic materials.
 Assimilation: plants that use carbon in photosynthesis, like when animals consume
plants or other animals.
 Release: plants and animals release carbon through respiration and decomposition.
Describe the nitrogen cycle, and explain the importance of nitrogen fixation to all living
organisms.
 The nitrogen cycle is required for the manufacturing of all amino acids and nucleic
acids. Nitrogen fixation is the transferring nitrogen by lightning and UV radiation.
Explain how phosphorus is recycled locally in most ecosystems.
 Phosphorus is recycled by: (then starts all over again)
Reservoirs: mainly rocks in which erosion transfers phosphorus to water and soil.
Sediments and rocks that accumulate on ocean floors return to the surface as a result of
lifting by geological processes. Assimilation: plants absorb inorganic phosphorus from
soils. Release: plants and animals release phosphorus when they decompose.
Describe how the carbon cycle differs in terrestrial and aquatic systems.

Describe how increased atmospheric concentrations of carbon dioxide could affect the
Earth.

Describe how human interference might alter the biosphere.
 Human activity damages the biosphere. Exponential growth, destruction of habitat for
agriculture and mining, pollution from industry and transportation, and many other
activities all contribute to the damaging or altering of the environment.