O2 Assessment Study Guide--KEY
1. What is biodiversity? Make sure to describe all three components of biodiversity in
your response.
 Biodiversity is the variety of all life; it includes all of the genes, species and
habitats in a given area.
i. Species diversity: number and variety of species in a given area
ii. Genetic diversity: variation of genes within a species
iii. Ecosystem diversity: variety of ecosystems within an area.
2. In what ways does having high biodiversity improve an ecosystem? Impact humans?

High biodiversity impacts humans because of all the ecosystem services that
are provided to us. These include: moderating weather events, maintaining
soil quality, maintaining air quality, detoxification and decomposition of waste
products, offering pest control, pollination and crop production, seed dispersal
and potential medicines
3. How does biodiversity impact our food supplies? Why should all of us be concerned
about maintaining high biodiversity (especially in food crops) worldwide?



Important biodiversity services: pest control, pollination. These are free (saving
us billions of dollars annually), better for the environment and more effective
than the technological “fixes” we’ve developed.
Growing a variety of crops is much healthier and more stable than monoculture
(disease is more of an issue in a monoculture)
Stable ecosystems offer a wide variety of species that all provide similar
function if one disappears another species can take over and provide the same
service.
4. What is fair trade? How does fair trade improve biodiversity?
 Fair trade is NOT a product; it’s a process that refers to products grown/sold in
a manner that helps biodiversity. In order to be certified fair trade,
manufacturers must ensure that their farmers earned a fair price, that the
product was produced under fair labor conditions, and it can be traded directly
(no middle man to eat up profits). The organizations handling the money and
decisions are democratic and transparent. Oftentimes, the money is directly
impacting the community development in the creation of schools, safe drinking
water facilities, etc.
 In terms of protecting/improving biodiversity—fair trade products are strictly
limited in the types/amounts of pesticides that are allowed. Therefore, there is
less pesticides used to grow this product which is a benefit for the organisms in
the area. Also, many of these companies aren’t a multinational company,
which means they are more likely small, family managed farms that will not eat
up a huge portion of the landscape which also benefits the biodiversity of the
area.
5. What are the major threats to biodiversity worldwide? (H.I.P.P.O.) Provide a real
world example of each of them.
 Habitat Destruction/Fragmentation: changing a habitat to suit human needs
i. Example: deforesting a large area for a new waterpark, urban sprawl

Invasive Species: any organism that has been relocated somewhere other
than its original habitat. They usually cause trouble (most often because they
have no natural predator in this new environment)

Population Growth (of Humans): A larger population will necessitate more land
devoted to food production and homes. With more humans, the need for fuel
and water increases. This likely will impact habitats by destroying homes for
other species.

Pollution: Often leads to species loss and ecosystem degradation.
i. Example: Asian beetles, Emerald Ash Borer, Zebra Mussels, Purple Loosestrife
i. Example: Commercial building on previously wild areas
i. Example: Global Climate change—most species live within a narrow temperature
change. Anything that deviates too far from that window will alter feeding and
reproductive behavior which can be devastating.
ii. Example: Acid Precipitation—similar to temperature, many species can only tolerate a
narrow window of pH values. As the lakes and other bodies of water, soils and air
become more acidified, many species have to relocate or have died out due to the lack
of ability to adjust.

Overconsumption: Using more resources than necessary to survive
i. Example: Industrialized countries make up 25% of the world’s population, but use 75%
of the world’s resources.
ii. Example: US makes up 5% of the world population, but creates 33% of the world’s air
pollution!
6. How do non-native species get to new areas? Why are they successful? How does
the arrival of one non-native species have the potential to ripple through the entire
food web?


Non-natives (aka alien, invasive, introduced, exotic) species can arrive in a new
area a number of ways:
i. On purpose—someone may introduce something because it reminded them of
“home”, they wanted to cook/eat it, it has medicinal qualities, etc.
ii. Accidentally—many things arrived via ballast water of ships, or in suitcases,
crates etc that are part of trade and travel.
iii. Move on own—some mobile species may have been forced out of their original
habitat so they migrate on their own.
They are successful (oftentimes) because they can outcompete the natives.
Perhaps they bloom earlier, come out of the ground and shade out the natives
impeding the reproduction of the native and allows the non-native to gain all the
sunlight and reproduce. They often don’t have natural predators in their new
land which allows them to grow their populations unchecked by a predator.
i. Worldwide many NATIVE organisms are becoming endangered as a result of
the impact of non-natives.
7. Why does a farmer who plants one crop have to apply many more pesticides than a
farmer who plants a diverse farm?

Monoculture is like a buffet table for disease organisms. If a disease infects a
few plants, it will quickly spread across the entire crop. Therefore, farmers
have to be on constant alert for disease and use a lot of pesticides. In addition,
a diversely planted farm would have homes for pest control species like birds
and certain beneficial insects that you will not find in monoculture.
8. What is the relationship between the size of a population and its genetic diversity?


As a population becomes smaller (due to migration, deaths, splitting of herd,
etc) the number and variety of genes decreases. This leads to LESS
biodiversity of the group as a whole since there are fewer combinations
(reproductive partners) available to create new organisms.
Populations that are more genetically diverse to begin with will be able to
withstand more types of ecosystem stresses (diseases, droughts, hunting) and
will be more stable.
9. What can be done to preserve biodiversity worldwide?





Maintain habitats and ecosystems
Cut down on overconsumption of goods
Buy sustainable and fair trade products
Cut back on pollution
Be more aware of your actions and how they
impact the environment

Gene banks

Captive breeding programs

Zoos and conservancies engaging in education
of the population
Individual actions
Worldwide efforts
Make sure that you look at all the activities that we did in this
outcome…revisit your Green sheets!