Unit 2

Question 1

What are some of the ways organisms get energy from their environment?

Answer 1

• Photosynthesis (plants get energy from the sun)
• Chemosynthesis (organisms create their own energy)
• Consuming other organisms

Question 2

A decrease in biodiversity is evidence that an ecosystem has been impacted by…

Answer 2

Human activities

Question 3

What is a species richness? How is it found?

Answer 3

• The number of species in a given area
• Found by counting the number of different species present in a given area

Question 4

What is species evenness? How is it found?

Answer 4

• How evenly distributed the species are
• Considers how common or rare each species is within the community
• Found by counting the number of different species present and the number of individuals of each species

Question 5

What is a Climax Community?

Answer 5

• The final, stable stage of ecological succession in a given area
• Plant and animal species present are well-adapted to the local climate and conditions, reaching a state of equilibrium with minimal change over time

Question 6

When trying to determine if a disturbed ecosystem has reached a Climax Community you need to consider the…

Answer 6

• The producers
• They stay in one place, heterotrophs are more likely to move in or out of the ecosystem.

Question 7

What is the purpose of a control group in an experiment?

Answer 7

• Creates a baseline for comparison
• Allows researchers to see the effect of the independent variable

Question 8

What is mono-cropping

Answer 8

The practice of growing the same crop year after year in the same location

-Is more likely to be wiped out due to lack of genetic diversity

Question 9

What are the potential negative impacts of mono-cropping?

Answer 9

• Reduced biodiversity
• Soil degradation, which is harm to soil fertility
• Pesticide resistance
• Impact on pollinators
• Damage to natural environment

Question 10

How can the biological diversity of an ecosystem be measured or assessed?

Answer 10

Simpson’s diversity index, which take into account both richness and evenness when calculating a single value representing overall biodiversity

Question 11

Are all externalities negative?

Answer 11

No, they can be both positive or negative

Def) an effect of an economic activity that impacts a third party who is not directly involved in the transaction

Poss EX) someone planting a tree

Neg EX) factory polluting a river

Question 12

Why are smaller populations more susceptible to population changes?

Answer 12

Genetic drift:
- In smaller populations, random fluctuations in allele frequencies are more likely to occur, leading to the loss of genetic diversity and potential negative impacts on the population’s ability to adapt

• More susceptible to bottlenecking due to lack of gene pool

Question 13

What is the Island Biogeography Theory?

Answer 13

The number of species found on an island is directly related to its size and distance from the mainland

Larger and closer to mainland = more biodiversity

-Based on genetic diversity, biodiversity, and habitat diversity

Question 14

What is the difference between a keystone specie and a indicator specie?

Answer 14

A keystone species actively shapes the ecosystem, while an indicator species passively reflects its condition

Keystone EX) Beavers which create wetlands that support a variety of other species by building dams

Indicator EX) Certain types of lichen, which are highly sensitive to air quality

Question 15

What characteristics allow an ecosystem to recover from a disturbance?

Answer 15

Species diversity, genetic diversity, habitat diversity
= creates resilience

Question 16

What are the 4 types of Ecosystem Services?

Answer 16

Provisioning - provide resources like food and lumber

Regulating - moderation of natural processes like pollination, filtering water, cleaning air

Cultural - aesthetic enjoyment

Supporting - necessary for every other ecosystem service like producing oxygen, nutrient cycling

Question 17

What is the difference between fast growing tree species (coniferous) and slow growing tree species (deciduous).

Answer 17

Fast growing tree species (coniferous): Stay green year round (pine, ceder)

Slow growing tree species (deciduous): Leaves fall off in Autumn (oat, ash, beech, maple)

Question 18

Species Richness

Answer 18

The number of species in an area

Question 19

Slash and Burn Agriculture

Answer 19

A farming method that involves cutting down and burning vegetation to clear land for growing crops

• loss of habits, carbon dioxide release, trees lose ability to absorb carbon
• some nutrients that are in those producers get returned back to the soil

Question 20

Anthropogenic

Answer 20

Environmental change caused or influenced by people, either directly or indirectly

Question 21

Selective Pressure

Answer 21

An evolutionary force that causes a particular phenotype (observed characteristics) to be more favorable in certain environmental conditions

3 types:
-Directional: Most common
-Stabilizing
-Disruptive: Least common

Question 22

Benthic

Answer 22

Anything ecosystem associated with or occurring on the bottom of a body of water

Question 23

Coevolution

Answer 23

• Occurs when species evolve together with favorable characteristics

-Often happens in species that have symbiotic relationships

EX) flowering plants necks getting bigger and deeper = their pollinators are able to get pollen easier