General Principles

Question 1

ecology

Answer 1

the study of how organisms interact with one another and with their environment

Question 2

environment

Answer 2

living portion: biotic component (organisms)

nonliving portion: abiotic component (air, soil, water)

Question 3

population

Answer 3

a group of individuals of the same species occupying a common geographic area

Question 4

community

Answer 4

two or more populations reside in the same geographic location

Question 5

ecosystem

Answer 5

a community and its surrounding abiotic factors

Question 6

biome

Answer 6

a collection of ecosystems with similar climates and communities

Question 7

food webs

Answer 7

the flow of energy within an ecosystem by linking together several food chains

Question 8

autotroph

Answer 8

producer, an organism that begins the food chain by using energy from light/chem. reactions to produce organic compounds from inorganic compounds

Question 9

heterotroph

Answer 9

consumer, can’t produce its own organic compounds and must consume other organisms to obtain them

Question 10

detritivore

Answer 10

consumes detritus (dead and decaying organic matter)

Question 11

decomposer

Answer 11

breaks down dead and decaying organic matter using biochemical reactions

Question 12

trophic level

Answer 12

each “step” in the food chain

Question 13

hydrologic cycle

Answer 13

the cyclic movement of water between Earth’s hydrosphere, atmosphere, cryosphere, biosphere, and lithosphere

Question 14

carbon cycle

Answer 14

the cyclic movement of carbon in different chemical forms from the environment to organisms then back to the environment

Question 15

nitrogen cycle

Answer 15

the cyclic movement of nitrogen in different chemical forms from the environment to organisms then back to the environment

Question 16

phosphorous cycle

Answer 16

the cycle that involves the uptake of phosphorus by organisms; phosphorus is found mainly in rocks but natural weathering processes can make it available to biological systems

an essential nutrient for plants and animals in the forms of phosphate ion and hydrogen phosphate ion

constituent of DNA/RNA (ATP/ADP) and lipids

Question 17

commensalism

Answer 17

an interaction which is beneficial to one species

Question 18

amensalism

Answer 18

an interaction which is detrimental to one species

Question 19

antagonism

Answer 19

an interaction beneficial to one species but bad to the other

Question 20

competition

Answer 20

an interaction that is detrimental to both species

Question 21

intraspecific

Answer 21

among individuals of the same species

Question 22

interspecific

Answer 22

between different species

Question 23

niche

Answer 23

conditions in which an organism lives and the way the organism uses those conditions

Question 24

competitive exclusion princple

Answer 24

no two species that occupy the same niche can coexist indefinitely; eventually one will be dominant and the other, extinct

can be avoided by having organisms undergo a shift towards different niches

Question 25

population growth

Answer 25

affects environment through rise in carbon emissions, pesticides and fertilizers, and destruction of habitat

Question 26

Deforestation

Answer 26

destruction of forest environments for wood or human development.

results in a loss of habitat for many species, therefore hurting biodiversity. The loss of photosynthesis results in less buffering of carbon dioxide levels. A method of clearing forests for agriculture called slash-and-burn involves the burning of vegetation and releases a massive amount of carbon into the atmosphere.

Question 27

Desertification

Answer 27

Desertification is a type of deterioration of land in which a relatively dry region becomes more and more arid. The primary cause of desertification is the removal of vegetation, which may occur as a result of several factors, such as drought and human activities. The removal of vegetation makes soil more susceptible to erosion. After the topsoil is eroded, infertile soil layers are left to harden into caliche, which hinders further plant growth. The removal of vegetation also results in less evapotranspiration, and therefore even drier conditions.

Many different countermeasures are used to prevent and combat desertification, such as reforestation. Reforestation of certain plants can help enrich the soil and restore its fertility. Reforestation also occurs in the form of windbreaks and woodlots. Windbreaks are rows of trees planted in a way as to provide shelter from the wind, and can help reduce soil erosion and evapotranspiration. Woodlots are like forests, but are generally distinguished by being too small for full-scale commercial harvesting.

Question 28

survivorship

Answer 28

percentage of remaining survivors of a population over time, usually shown graphically

Question 29

type 1 survivorship curve

Answer 29

most individuals live out their life span and die of old age (e.g. humans)

Question 30

type 2 survivorship curve

Answer 30

individuals die at a constant rate

Question 31

type 3 survivorship curve

Answer 31

most individuals die early in life