Final Exam NSCI 115 2025

What is Environmental science?

Interdisciplinary approach to solving environmental issues

What are biotic vs. abiotic factors?

Biotic is anything alive, abiotic is rocks, weather, water, etc.

What is entropy?

The amount of disorder

What is anthropocentrism?

Focused on humans

If everybody in the world used resources at the rate that people in the United States do, what would be the result?

We would run out of resources quickly

What is the shape of an exponential growth curve?

J-shaped curve

What is the difference between intrinsic and instrumental value?

Intrinsic - value because it exists

Instrumental - provides a service

What is environmental justice?

Fair distribution of resources, not using poorer communities to build water facilities, factories, etc.

What is sustainability?

Living within our means, saving resources for future generations

Define ecosystem, community, and population with respect to species.

ecosystem - environment and its biotic and abiotic factors

community - the variety of species in an area

population - the number of a given species

How does a food chain differ from a food web?

food chain is simple, linked like algae - bugs - fish - shark

food web is a complex linked system

Know the difference in the trophic levels - producer, consumer (primary, secondary, tertiary) as well as the difference between herbivore, carnivore, and omnivore.

producer - photosynthesizer; plants

primary consumer - herbivore (eats plants)

secondary consumer - carnivore (eats animals) or omnivore (eats plants and animals)

What is the 10% rule with respect to ecological pyramids?

10% of energy is passed from one trophic level to the next, 90% of energy is lost between each trophic level

Understand the basics of the hydrologic (water) cycle

evaporation - condensation and/or transpiration - precipitation - runoff

Which of the chemical cycles from the PPT has no atmospheric phase?

Phosphorus has no atmospheric phase

How do humans release sulfur into the atmosphere?

burning fossil fuels

How does phosphorous get into the atmosphere?

It doesn't

What is natural selection?

organisms with more favorable traits will naturally adapt to their environment

What is homology? (PPT)

similarities in anatomical structures

What are vestigial organs? (PPT)

organs contains by an organisms that have no use; likely had a use in the past

What is the driving force behind natural selection? i.e. what causes new, useful traits to appear?

Mutations

How does Darwin's theory of evolution differ from Lamarck's theory?

Lamarck thought that organisms could develop favorable traits by their own efforts. Darwin thought they were traits the organism was born with.

What types of organisms did Darwin study on the Galapagos Islands that helped solidify his ideas on natural selection? What were the specific features/traits that Darwin noticed?

finches - had different beaks based on the food supply

tortoises - had different necks based on the food supply on their particular islands

What is extinction?

when all of a particular species is gone

What is parasitism, commensalism, and mutualism?

parasitism - one organism lives on another and causes harm

commensalism - one organism benefits; the other is unaffected

mutualism - booths species benefit

How many species per year are we currently losing?

50,000 per year

What happens with inbreeding?

negative mutation; decreased genetic variety

What do the extinct, threatened, near-threatened categories mean?

extinct - no more of a specific species exists

threatened - could become extinct in the near future

near threatened - numbers are decreasing, could become threatened

What is HIPCO?

H - habitat loss
I - invasive species
P - pollution
C - climate change
O - overharvesting

How were bison affected in the 1800s?

They were hunted to near extinction as the European settlers took over areas belonging to Native Americans

What is bioaccumulation?

an increased concentration of a chemical within an organism over time

What is the current world population?

8.1 billion people

What is demography?

Collection of data about individuals such as income, race, language spoken, education level

What countries have the highest populations?

India, China, U.S.

How does education relate to birth rate?

Higher education decreases birth rate

How does life span differ from life expectancy?

Life span - the longest a species can live

Life expectancy - how long a person can expect to live

When did world population reach 1 billion?

1800

What is undernutrition vs malnutrition?

Undernutrition – not enough calories

Malnutrition – plenty of calories, not enough key nutrients

What food accounts for most of the food calories consumed yearly?

Wheat

What is salinization?

An area becoming rich in salts

What are organic fertilizers commonly composed of?

Manure

What is a pesticide?

Targets and kills pests that affect plants

What is the difference between an herbicide and an insecticide?

Herbicide kills plants (weeds)

Insecticide kills bugs

What is a GMO?

Genetically modified Organisms

What is desertification?

Turning land into a barren field 

In the past 110 years, life expectancy in the US, as well as in other countries, has changed significantly.  How has it changed and what contributed to the change? 

Technology advances in medicine

What are the steps to the scientific method?

Ask a question

Do background research

Form a hypothesis

Conduct an experiment

Analyze data

Draw a conclusion

Share results

Although the US only has 4.5 percent of the world’s population, it is a major contributor to resource consumption and pollution production.

How does education relate to birth rate? 

Higher education = lower birth rate 

How has technology affected the population?

increased it 

What is Catastrophism?

Earth’s features formed by sudden, violent events like floods or volcanoes.

What was the name of Darwin’s ship? 

The Beagle 

What is a biome? 

physical environment that has characteristic plants and animals

What are the major biomes?

Tundra, desert, tropical rainforest, savannah, temperate forest, coniferous forest

What are the characteristics of a tropical rain forest? 

hot and wet year round, thin nutrient soil.

What are biotic vs abiotic factors?

biotic is living and abiotic is non living

What are benthic vs. pelagic communities?

Benthic communities live on or near the ocean floor;

pelagic communities live in the open water away from the bottom.

What are the zones of light penetration?

Euphotic zone – Sunlit; supports photosynthesis.

Disphotic zone – Dim light; no photosynthesis.

Aphotic zone – No light; completely dark. 

What are the vertical zones in a lake?

Littoral zone – Shallow, near shore, sunlight reaches bottom. 

Limnetic zone – Open surface water, lots of light, photosynthesis occurs. 

Profundal zone – Deep water, little or no light, colder. 

Benthic zone – Bottom of the lake, low oxygen, decomposers live here.

What biome is the most impacted by humans?  Which biomes are the least affected?

Deciduous forests are the most affected; arctic deserts and tundra are the least

What is integrated pest management (IPM)?

IPM is a pest control method that uses multiple strategies to reduce harm to people and the environment.

emergent disease

An emergent disease is one never known before, or has been absent for at least 20 years.

define health

A state of physical, mental, and social well-being.

define disease

A disorder that disrupts normal body functions.

define toxic

Harmful or poisonous to living organisms.

define hazardous

Dangerous; can cause harm or injury.

define neurotoxins

Substances that damage the nervous system.

define allergen

a substance that triggers allergic reactions

define mutagens

agents that cause genetic mutations

define teratogens

substances that cause birth defects

define carcinogens

substances that cause cancer

define Synergistic Reaction

When two substances together cause a stronger effect than alone

define acute effects

Immediate or short-term health effects

define chronic effects

Long-term health effects from repeated or prolonged exposure

How is water distributed on Earth? 

Most is salt water 97%, most of the freshwater is frozen in glaciers 

What are the steps of the water cycle?

evaporation, condensation, precipitation, runoff 

What percent of the planet is covered in water?

70%

What is most of California’s water used for?

Agriculture

What has happened on the West Side of the San Joaquin Valley due to too much water being withdrawn from the aquifer?

subsidence

What is a confined aquifer?

it has impermeable layers both above and below the aquifer

What is an unconfined aquifer? 

it has no impermeable layer below the aquifer

What is point source pollution vs non point pollution?

With point pollution, we can identify the exact source – could be coming from a pipe from a factory. Non-point source pollution is more difficult to pin to an exact source. It could be runoff from several farms or parking lots for example.

three major pollutants in water

Lead, arsenic, and mercury

What is MCL with respect to water?

Maximum contamination levels for toxins in water

What is the composition of air?

Nitrogen (N₂) – 78%

Oxygen (O₂) – 21%

Argon (Ar) – 0.93%

Carbon dioxide (CO₂) – 0.04%

Other gases (neon, helium, methane, etc.) – trace amounts

What are the layers of the atmosphere?

Troposphere 

Stratosphere 

Mesosphere 

Thermosphere 

Exosphere

Where is ozone concentrated?

stratosphere

What is ozone?

gas made of three oxygen atoms (O₃) that absorbs harmful UV radiation from the sun.

What international treaty greatly reduced the use of CFCs?

Montreal Protocol

What is the greenhouse effect? 

the process where gases in Earth’s atmosphere trap heat, keeping the planet warm.

What are the greenhouse gases? 

Carbon dioxide (CO₂)

Methane (CH₄)

Nitrous oxide (N₂O)

Water vapor (H₂O)

Ozone (O₃)

CFCs (chlorofluorocarbons)

What is indoor pollution?

the presence of harmful pollutants inside buildings, like smoke, mold, chemicals, or radon, that affect air quality and health.

What are the major air pollutants?

Carbon monoxide (CO)

Sulfur dioxide (SO₂)

Nitrogen oxides (NOₓ)

Particulate matter (PM)

Ozone (O₃)

Lead (Pb)

Volatile organic compounds (VOCs)

What are some natural sources of air pollution?

volcanes, lightning, forest fires, plants.

What are some anthropogenic sources of air pollution?

on-road vehicles, power plants, industrial processes, waste disposal

What is particulate material?

mix of tiny solid particles and liquid droplets in the air, like dust, soot, and smoke, that can harm lungs when inhaled.

What is anthropogenic?  

caused by humans, especially relating to environmental pollution or changes.

Why is the ozone layer important? 

It blocks harmful UV radiation from the sun, protecting living things from skin cancer, eye damage, and other health and environmental problems.

What is the difference between tropospheric ozone and stratospheric ozone?

Stratospheric ozone (good) = protects life by blocking UV rays.

Tropospheric ozone (bad) = air pollutant that causes respiratory problems and harms ecosystems.

What chemicals are responsible for breaking up ozone?

CFCs chlorofluorocarbons