4.1

Question 1

Autotroph

Answer 1

synthesises their own organic molecules from simple inorganic substances. Energy derived from sunlight (photosynthesis) or oxidation of molecules (chemosynthesis)

Question 2

Heterotroph

Answer 2

synthesises their organic molecules from other organisms

Question 3

Saprotroph

Answer 3

release digestive enzymes & absorb the external products of digestion. (facilitate breakdown of dead organic material) (bacteria)

Question 4

Detritivore

Answer 4

ingest organic molecules found in the non living remenants of organisms (eg: detritus or humus) (earthworms)

Question 5

Species

Answer 5

group of organisms that can interbreed to produce fertile, viable offsprings

Question 6

Population

Answer 6

group of organisms of the same species living in the same area at the same time

Question 7

Community

Answer 7

a group of populations living together and interacting with each other within a given area

Question 8

Ecosystem

Answer 8

a community and its abiotic environment

Question 9

Abiotic

Answer 9

the non living chemical and physical factors in an environment which affects ecosystems

Question 10

Biotic

Answer 10

the living components of an environment which affect an ecosystem

Question 11

Producers

Answer 11

the first organism in a food chain, also known as an autotroph, synthesizes its own organic molecules

Question 12

List of greenhouse gases

Answer 12

CO2, water vapor, methane, nitrogen oxides

Question 13

Nutrients for autotrophs

Answer 13

Carbon, Nitrogen, Hydrogen, Oxygen, Phosphorus (from air, water & soil)

Question 14

Scavenger

Answer 14

Feed on dead and decaying carcasses rather than hunting live prey

Question 15

An example of mixotroph

Answer 15

Euglena gracilis (photosynthesis & detritus)

Question 16

Nutrient

Answer 16

material required by an organism

Question 17

How are chemical elements recycled?

Answer 17

autotrophs obtain inorganic nutrients from air, water, soil, convert them into organic –> heterotrophs ingest organic compounds (used for growth & respiration) –> release inorganic byproducts –> organism dies –> saprotrophs decompose remains –> free inorganic materials in soil –> supply for autotrophs

Question 18

components required for sustainability in an ecosystem

Answer 18

energy, nutrients, recycling of wastes

Question 19

mesocosm

Answer 19

enclosed environments allowing small environment to be observed under controlled conditions

Question 20

positive association

Answer 20

two species that tend not to occur within the same habitat

Question 21

negative association

Answer 21

two species that tend not to occur within the same habitat

Question 22

competitive exclusion

Answer 22

one species utilises resources more efficiently, precluding survival of others

Question 23

resource partitioning

Answer 23

both species may alter their use of the environment to avoid direct competition

Question 24

quadrat

Answer 24

rectangular frame of known dimensions used to establish population densities

Question 25

(chi squared test) Null hypothesis

Answer 25

no significant difference between the distribution of two species (random distribution)

Question 26

(chi squared test) Alternative hypothesis

Answer 26

there is a significant difference between the distribution of species (species are associated)

Question 27

what are conditions to metabolism

Answer 27

method by which they obtain carbon, derive energy, generate reducing equivalents

Question 28

predator prey relationships

Answer 28

interaction whereby one organism hunts and feeds on another organism. Population levels are inextricably intertwined

Question 29

symbiosis

Answer 29

close & persistent interaction

Question 30

mutualism

Answer 30

both species benefit

Question 31

commensalism

Answer 31

one benefits, the other unaffected

Question 32

parasitism

Answer 32

one benefits at the detriment of other

Question 33

negative associations (competitions)

Answer 33

interaction between two organisms whereby the fitness of one is lowered by the presence of the other intraspecific: same species interspecific: different species

Question 34

competitive exclusion

Answer 34

one species uses resources more efficiently

Question 35

resource partitioning

Answer 35

both species alter their use of environment

Question 36

ecological niche

Answer 36

describes the functional positions and role of an organism within its environment composed of habitat, activity patterns, interactions, resources)

Question 37

Difference between fundamental niche and realised niche

Answer 37

fundamental: entire set of conditions under which an organism can survive (where it can live) realised: other species taken into account (where it does live)