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MIDTERM I ENVIRONMENTAL SCIENCES
STUDY GUIDE
1. Our environment is made up of all things with which we interact and they include both biotic
(living) and abiotic (non-living) factors.
i. Biotic Factors
1. Animals
2. Plants
3. Bacteria
4. Fungi
ii. Abiotic Factors
1. Sunlight
2. Temperature
3. Atmospheric gases
4. Water
5. Soil
2. Substances and energy sources needed for survival come in 2 categories; renewable and nonrenewable energy sources.
a. Renewable energy resources can be replenished over relatively short periods of time.
These can be destroyed if used more quickly than the resource can recover
1. Sunlight
2. Wind
3. Wave Energy
4. Timber
5. Water
6. Soil
7. Plants
8. Animals
b. Non-renewable energy is generated from the original organic material, with the aid of
heat and pressure, becomes a fuel such as oil or gas. Takes millions of years to create /
replenish
1. Earth minerals
2. Metal ores
3. Fossil Fuels (coal, petroleum, natural gas)
3. What is the difference between environmental science and environmentalism?
i. Environmentalism – is a one-sided activist social movement dedicated to
protecting the natural world.
ii. Environmental science –
1. Uses a systematic process for learning about the world and testing our
understanding of it
2. Gathers and analyzes information from a dynamic process of
observation, testing, and discovery
3. Strives to maintain objectivity in order to sort fact from fiction and the
view issues from multiple points of view.
4. Develop solutions to the problems we face.
4. What countries use most of the world’s non-renewable resources?
a. Most of the world’s nonrenewable resources tend to be consumed by people in the
United States, Canada, and other highly developed nations. In general, people in highly
developed countries are extravagant consumers; their use of resources is greatly out of
proportion to their numbers.
5. Highly developed countries represent less than 20% of the world’s population, yet they consume
approximately _________ % of the world natural resources and _________% of the world’s
pollution and waste.
a. Highly developed countries represent less than 20% of the world’s population, yet they
consume significantly more than half of its resources. According to the Worldwatch
Institute, highly developed countries account for the lion’s share of total resources
consumed: 86% of aluminum used, 76% of timber harvested , 68% of energy produced ,
61% of meat eaten, 42% of the fresh water consumed. These nations also generate 75%
of the world’s pollution and waste.
6. What is an ecological footprint?
a. Environmental scientists Mathis Wackernagel and William Rees developed the concept
of ecological footprint to help people visualize what they use from the environment.
Each person has an ecological footprint, an amount of productive land, fresh water, and
ocean required on a continuous basis to supply that person with food, wood, energy,
water, housing, clothing, transportation, and waste disposal.
7. Define sustainability.
a. The ability to meet current human economic and social needs without compromising
the ability of the environment to support future generations. A sustainable world is one
in which humans can have economic development and fair allocation of resources
without the environment going into a decline from the stresses imposed by human
society on the natural systems (such as fertile soil, water, and air) that maintain life.
When the environment is used sustainably, humanity’s present needs are met without
endangering the welfare of future generations
8. What is environmental science?
a. Environmental science is the interdisciplinary study of humanity’s relationship with
other organisms and the nonliving physical environment. Environmental scientists study
systems; each system is a set of components that interact and function as a whole.
9. What are some of the fields of study that play a role in Environmental Science?
1) Geology
2) Biology
3) Chemistry
4) Ethics
5) Social Science
6) Politics
7) Economics
10. Where does the ozone air pollution come from?
a. Ozone is created from a chemical reaction between smog and sunlight.
1. It starts with a bunch of cars
2. Vehicles burn fossil fuels
3. This releases hydrocarbons into the air
4. The hydrocarbons react with sunlight
5. Ozone (O3) is one of several reactions, but is well-known for its detrimental
effects on the environment and organisms
11. How does pollution affect the soil?
a. Once in the atmosphere, these oxides can mix with other chemicals to form more
harmful pollutants that either settle as ‘dry deposition’ or are washed out by rain and
fall as ‘wet deposition’.
1. Pollutants from air enter the soil
2. Contaminated leaves fall on ground and decompose
3. Rainwater transfers pollutants from air to soil
4. Decomposing contaminated animals can transfer pollutants to soil
5. This leads to Acidification of the soil and plant don't grow
6. Acidification leads to desertification.
7. Herbivores experience lack of food and population dwindle
8. Consumers now have limited food source as a result
12. How old is the Earth?
a. 4.5 billion years old. The planet Earth forms from the accretion disc revolving around the
young Sun with organic compounds (complex organic molecules) necessary for life
having perhaps formed in the protoplanetary disk of cosmic dust grains surrounding it
before the formation of the Earth.
13. The first living organisms that we have physical evidence of is the _________.
a. Cells resembling prokaryotes appear. These first organisms are chemoautotrophs: they
use carbon dioxide as a carbon source and oxidize inorganic materials to extract energy.
14. What are archaea?
a. The Archaea are prokaryotes, meaning that they have no cell nucleus or any other
membrane-bound organelles in their cells. Archaea were initially classified as bacteria,
receiving the name archaebacteria (in the Archaebacteria kingdom), but this
classification is outdated. Archaeal cells have unique properties separating them from
the other two domains of life (bacteria and eukaryote). Archaea use more energy
sources than eukaryotes: these range from organic compounds, such as sugars, to
ammonia, metal ions or even hydrogen gas. Salt-tolerant archaea (the Haloarchaea) use
sunlight as an energy source, and other species of archaea fix carbon; however, unlike
plants and cyanobacteria, no known species of archaea does both.
15. Explain the first global event called the “Great Oxygen Event” that changed our atmosphere to
contain more oxygen.
a. Photosynthesizing cyanobacteria evolved; they used water as a reducing agent, thereby
producing oxygen as a waste product.[31] The oxygen initially oxidizes dissolved iron in
the oceans, creating iron ore. The oxygen concentration in the atmosphere slowly rose,
acting as a poison for many bacteria and eventually triggering the Great Oxygenation
Event.
16. Explain the endosymbiotic theory of how Eukaryotic cells appear.
a. The endosymbiosis theory explains the origins of organelles such as mitochondria and
chloroplasts in eukaryotic cells. The first eukaryotic cells may have evolved when one
prokaryotic cells engulfed another. The prokaryote (bacteria cell) that was then trapped
inside. Both cells entered a symbiotic relationship, a close association between different
types of organisms over an extended time. However, to be specific, the relationship was
endosymbiotic, meaning that one of the organisms (the bacteria) lived within the other
(the eukaryotic cells). According to endosymbiosis theory, an anaerobic cell probably
ingested an aerobic bacterium but failed to digest it. The aerobic bacterium flourished
within the cell because the cell's cytoplasm was abundant in half-digested food
molecules. The bacterium digested these molecules with oxygen and gained great
amounts of energy. Because the bacterium had so much energy, it probably leaked
some of it as adenosine triphosphate into the cell's cytoplasm. This benefited the
anaerobic cell because it was now able to breathe aerobically, which means more
potential for energy gain. Eventually, the aerobic bacterium could no longer live
independently from the cell, and it, therefore, became a mitochondrion.
17. What evidence do we have of the endosymbiotic theory with regard to mitochondria?
a. The mitochondria reproduce independently using binary fission (asexually) and have
their own bacterial plasmid which is a circular strand of DNA.
18. List and define the levels of organization of life.
1. ORGANISM - All of the organ systems make a living organism, like a lion.
2. POPULTION - A group of the same organism living together in an area is
a population, such as a pride of lions.
3. COMMUNITY - Two or more populations interacting with each other
form a community, for example, lion and zebra populations interacting
with each other.
4. ECOSYSTEM - Communities interacting not only with each other but also
with the physical environment encompass an ecosystem.
5. BIOSPHERE - All of the ecosystems make up the biosphere, the area of
life on Earth.
19. Explain the food chain in term of energy flow in the ecosystem.
1. Energy enters the ecosystem as light energy (photons).
2. Producers transform light energy (PHOTONS) into chemical energy
(GLUCOSE) through photosynthesis
3. Some of this energy is converted to heat energy used for growth and
development and is no longer biologically useful. Only 10% of the
energy is transferred to the next level.
4. The energy flows from Photons  Producers  Primary Consumers 
Secondary Consumers  Tertiary Consumers  and so on.
20. How do most Producers get their energy?
a. Through photosynthesis - Producers (such as plants) are capable of
photosynthesis. The Producer takes water and Carbon Dioxide (CO2) in the
presence of sunlight (photons) and turns it into sugar (glucose) and oxygen
(O2).
21. What is evolution?
a. The genetic change of a species over time
22. How did the Blind Cave Fish evolve?
a. Used to be a normal fish with sight
b. Swam into cave
c. Liked the cave – no predators
d. Did not need eyes since no sunlight in cave
e. Lost eyes and eyesight after several generations!
23. Natural Selection
a. Genetic Traits that improve the rate of survival and having offspring, will persist
in the population.
24. Explain some of our vestigial traits
a. Vestigial traits are parts of us that made since for us to have a very long time ag,
but makes no sense for us to have now.
i. The Appendix - once aided our primate ancestors with the digestion of
cellulose-rich plants once aided our primate ancestors with the digestion
of cellulose-rich plants
ii. Your coccyx, better known as your tailbone, is the very last part of your
vertebrae, and is the remnant of a lost tail.