Ecology Unit Test

Question 1

Define ecology

Answer 1

(The study of how an organism interacts with its environment to “make a living” or survive)

Question 2

Levels of organization
(organism through biosphere)

Small to Large

Answer 2

• Organism (an individual)
• Species (a group of individuals which can breed to produce fertile offspring)
• Population (a species living in a defined area)
• Community (multiple species living within one defined area)
• Ecosystem (all the organisms living in one area including their physical environment)
• Biome (a group of ecosystems which share similar climates and organisms)
• Biosphere (The Earth)

Question 3

Food chains

Answer 3

(A series of organisms which energy is transferred from one organism to another)

Question 4

Food webs

Answer 4

(All the “feeding interactions” between all organisms of an ecosystem in which energy and matter are moved)

Question 5

Trophic levels

Answer 5

(Each level of a food chain or food web)

Question 6

Producers

(autotrophs – chemosynthesis and photosynthesis

Answer 6

• Producers (Organisms which create their own food)
• Chemosynthesis (The process by which inorganic substances are converted into sugars/food)
• Photosynthesis (The process by which sunlight are converted into sugars/food)

Question 7

Decomposers

Answer 7

(Consumers/heterotrophs that feed on dead organisms by chemically breaking them down, returning nutrients to soil)

Question 8

Consumers

(heterotrophs – herbivores, carnivores, omnivores)

Answer 8

• Heterotrophs (Organisms that eat other organisms to obtain food)
• Herbivores (Organisms that only eat producers/autotrophs)
• Carnivores (Organisms that only eat other herbivores)
• Omnivores (Organisms that only eat both producers/autotrophs and heterotrophs)

Question 9

Three types of ecological pyramids:
energy, biomass, numbers

Also, know what biomass means!

Answer 9

• Biomass (The total amount of living tissue in a trophic level)
• Pyramid of Energy (A diagram which explains how energy is transferred between organisms on different trophic levels)
• Pyramid of Biomass (A diagram which compares the amount of biomass between species on different trophic levels)
• Pyramid of Numbers (A diagram which compares the populations of species on different trophic levels)

Question 10

10% Rule

Answer 10

(Only 10% of the energy stored in an organism is passed on to the next trophic level. The remaining 90% goes to life processes and the rest is lost as heat)

Question 11

Biogeochemical cycles

Know each biogeochemical cycle!

Answer 11

How matter [elements] are cycled between the atmosphere, hydrosphere, geosphere and biosphere
- Water Cycle
- Nitrogen Cycle
- Carbon Cycle

Question 12

Niche

Know its principle as well!

Answer 12

(The role an organism plays in its ecosystem)
- Competitive exclusion principle (No two species can occupy the same niche in the same habitat at the same time)

Question 12

Greenhouse effect

(caused by greenhouse gasses – know them)

Answer 12

• Greenhouse effect (The warming of the Earth caused by excessive release of greenhouse gases)
• Greenhouse gasses ([Carbon Dioxide and Methane] Gasses which cause the greenhouse effect)

Question 13

Biotic and abiotic factors

Answer 13

• Biotic factors (Factors which are caused by organisms interacting with one another)
• Abiotic factors (Factors which are caused by organisms interacting with the environment)

Question 14

Predation

Answer 14

(The act of one organism hunting and killing another, known as prey)

Question 14

Symbiotic relationships

(know the 3 types and give examples)

Answer 14

• Symbiosis (An interdependent relationship between two organisms)
• Commensalism (One organism benefits and the other is not harmed nor helped)
• Mutualism (Both organisms benefit)
• Parasitisms (One organism benefits and the other is harmed)

Question 15

Competition

Answer 15

(Struggle between organism for common resources)

Question 15

Emigration

Answer 15

(Organisms leave their population to join another population)

Question 16

Ecological Succession (primary and secondary)

Know def. of Ecological Succession as well!

Answer 16

• Ecological Succession (Gradual process which ecosystems change and develop over time)
• Primary Succession (Succession which begins in regions unable to sustain life [Devoid of soil]])
• Secondary Succession (Succession which begins after ecosystems created by Primary Succession are destroyed, and are recolonized by these native species, bringing back the ecosystems)

Question 16

Birth rate

Answer 16

(The net number of births in a population, increases size)

Question 16

Immigration

Answer 16

(Organisms from a different population join a new population)

Question 16

Pioneer species

Answer 16

(The first organisms appearing in barren ecosystems devoid of life, and bring about Primary Succession)

Question 16

Population density

Answer 16

(Number of individuals per unit of area)

Question 17

Limiting factors

Answer 17

(Conditions that limits the growth of a population)

Question 17

Resources

Answer 17

(Anything essential for an organism’s survival)

Question 17

Density-dependent limiting factors

Answer 17

(Limiting factors which occur only if a population reaches its maximum density or carrying capacity)

Question 17

Death rate

Answer 17

(The net number of deaths in a population, decreases size)

Question 18

Exponential growth (J-shape curve)

X-axis = Time
Y-axis = # of Organisms
Line = Change over time

Answer 18

(Caused by unlimited resources and lack of predation and competition)

Question 18

Sustainability

Know all ecosystem services!

Answer 18

• (Using ecosystem resources in ways that preserve ecosystem services)
• Food production
• Nutrient cycling and soil structure
• Purifying water
• Storing carbon (removes from atmosphere)
• Regulating pests and pollinating crops
• Protecting land against extreme weather

Question 18

Logistic growth (S-shape curve)

X-axis = Time
Y-axis = # of Organisms
Line = Change over time
Horizontal Line = Carrying capacity

Answer 18

(Caused by limiting factors such as competition for resources and predation)

Question 18

Nitrogen Cycle

Answer 18

([Needed for DNA, RNA and Protiens] The cycling of nitrogen between atmosphere, hydrosphere, geosphere and biosphere)

Question 18

Water Cycle

Know all other processes for water cycle!

Answer 18

• ([Needed to for all organisms to live] The cycling of water between atmosphere, hydrosphere, geosphere and biosphere)
• Evaporation (Heating water from liquid to vapor)
• Condensation (Vapor cooling to become liquid)
• Precipitation ([Rain, ice, snow, fog, etc.] Returning water back to the ground level)
• Transpiration (Evaporation of water from plants)

Question 19

Carbon Cycle

Answer 19

([Needed for structure] The cycling of carbon between atmosphere, hydrosphere, geosphere and biosphere)

Question 19

Density-independent limiting factors

Answer 19

(Limiting factors which occur regardless of a population’s capacity/density)

Question 20

Biodiversity – why is it important? What are the different types?

Answer 20

• (Biodiversity is important because it causes ecosystem services)
• Genetic Diversity (Diversity of genes/traits within a population)
• Ecosystem Diversity (Different habitats on the planet)
• Species Diversity (Different organisms on the planet [~1.8 million species])

Question 21

Human threats on biodiversity (HIPPCO)

Answer 21

• Habitat fragmentation (The splitting of habitats due to deforestation for urban development)
• Invasive species (Non-native species which wreak havoc on an ecosystem by overpopulating, which causes fierce competition for resources, due to no predators in that environment for such species.
• Pollution (Introduction of contaminants into the natural environment that cause adverse change)
• Human population growth (Human population growth causes excessive and wasteful consumption of resources, which lead to premature extinction of some species)
• Climate change (Increased CO2 emissions due to human activity results in an increase in greenhouse gases leading to global temperatures to drastically increase; causes extreme weather conditions and drives species to extinction)
• Overhunting/Overharvesting (Killing organisms for food or sport, lowering the amount of each population; causes food webs become unstable and for less available resources)

Question 22

Biological magnification

Answer 22

(The increase in concentration of a pollutant, e.g a pesticide, in the tissues of organisms at successively higher levels in a food chain)

Question 23

Goal of conservation with examples

Answer 23

• Conservation (Goal: To utilize sustainable resources so that they are available for many generations ahead)
• Ex. Switching from non-renewable fossil fuels to renewable energy such as solar, wind, water, etc.
• Ex. Limit overhunting of certain species, and habitat fragmentation from deforestation, to protect their ecosystem services.