Ecology is the study of the structure, function, and interactions among natural systems in the biosphere.
Abiotic factors are non-living physical conditions such as weather, climate, geological characteristics and phenomena, and geographical structure. Biotic factors are those 'living' characteris...
Bio 121 Exam 1 Questions and Complete
Solutions
Ecology ✅is the study of the structure, function, and interactions among natural
systems in the biosphere.
Abiotic ✅factors are non-living physical conditions such as weather, climate, geological
characteristics and phenomena, and geographical structure. Biotic factors are those
'living' characteristics of the environment such as organisms and their products.
Biosphere ✅The biosphere is the area on Earth where life may exist. The physical
platform for the biosphere is created by the atmosphere (mixture of gases enveloping
the Earth), hydrosphere (the water component of Earth), and lithosphere (the Earth's
crust and upper mantle).
What component of the biosphere do you think could be damaged most easily by
human activities? C) Explain why. ✅The atmosphere is the most fragile of the three
physical spheres and it has the most immediate impact on life. The hydrosphere also is
subject to impact, but it is more resilient and able to absorb more abuse before obvious
degradation appears.
The atmosphere is constantly exchanging gases and other materials with the planet and
space. These exchanges are often rapid. The atmosphere is very thin, and has a lower
capacity to absorb and process pollutants than the other two spheres. It also has the
greatest and most immediate impact on life on Earth, for it acts as a shield and 'blanket'
protecting and warming the Earth.
) Name the 5 main environmental problems (from the notes). B) Which one is
considered to be the root of all the others? C) Explain why. ✅Pollution, Depletion of
natural resources, Changes in global conditions, War, Overpopulation.
(&C) Overpopulation is the root of all the other problems because as the population
increases it puts increasing pressure on natural resource use, increases the amounts of
pollution, which increases the rate of global changes. Also, as the population increases
there is more conflict over land and natural resources, and warfare is a massive waste
of resources and produces much pollution.
Explain what ecosystem services are and why they are important to your life.
✅Ecosystem Services are the natural processes that occur in ecosystems which
provide 'services' which allow human existence. These natural cycles have always
occurred, and humans have 'used' these services for survival.
These services include purifying water, air, soil, regulating the climate, producing the
resources required to grow our food, and removing wastes.
Human activities may disrupt or destroy these processes to the detriment of organisms
living in the ecosystem, including the humans.
, Differentiate (describe the differences) between the environmental ethics of
Ecocentrism, Biocentrism, and Anthropocentrism. B) Which of these ideas most closely
describes your environmental ethic, and explain why. ✅Ecocentrism is the belief that
actions should be taken to preserve and protect ecological systems and all the biotic
and abiotic components therein. This is a holistic approach that looks at a very large
scale of influence. Ecocentric actions would work to preserve ecosystem services.
Biocentric persons believe that all living things have inherent value and should be
protected and preserved regardless of human desires.They would support actions
which promoted various components of ecosystems which support all life.
Anthropocentrism is a belief that human needs outweigh all other interests in the
environment. They disregard and devalue non-human life and support actions which
benefit humans regardless of their impact on other life forms. All activities should be for
the benefit of humans
Which would you predict to be more sustainable... An Agrarian or Industrial society?
Explain your reasoning. ✅In general, agrarian societies are more sustainable because
they operate on a cyclical, sustainable framework that rejuvenates itself rather than the
linear, non-sustainable system of industrial societies.
Agrarian systems are sustainable because they are solar-powered. They also return
(recycle) unused or 'waste' materials back into the flow of energy and materials making
them a renewable resource, contributing to the natural cycle (like ecosystems).
Industrial systems extract resources, consume energy and materials, and then discard
wastes without recycling them back into the resource 'bank'.
Explain why the biosphere is essentially solar-powered. ✅The Sun supplies heat that
warms the planet (with the help of the atmosphere acting as a 'blanket'), maintaining
areas of liquid water and keeping temperatures in the ranges able to support life.
The Sun's heat and radiation drives the hydrologic cycle and atmospheric weather
systems that distribute heat and water across the planet. This provides water and
energy to life forms everywhere.
Light energy from the Sun provides the energy source driving photosynthesis, which
captures the Sun's energy in molecules of glucose. This sugar then provides high-grade
chemical energy to almost all other life forms on Earth, and is the basis for the economy
of Nature.
Explain what causes the different seasons of the year in the temperate zones. As part of
your answer, be sure to describe the relationship between the Earth and Sun at different
times of the year. The term 'angle of incidence' should be part of your answer. ✅The
Earth rotates (spins) on an axis that is tilted as it orbits the Sun during the year. This tilt
exposes the northern and southern hemispheres of the Earth to varying intensities of
solar radiation during the year. This produces the different seasons of the year in the
temperate zones because the angle of incidence increases and decreases during the
year. The closer the angle of incidence is to 90-degrees, the more intense the radiation
and so more heat. The varying heat during the year creates summer and winter.
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