Definitions

Question 1

Define ‘ecosystem’

Answer 1

A community of organisms and it’s environment - an ecological system (includes both the living inhabitants and the non-living surroundings)

Question 2

Define ‘population’

Answer 2

A group of organisms of of the same species occupying a particular space at a particular time

Question 3

Define ‘gene pool’

Answer 3

The gene pool is the sum of all the genes of all the individuals in a population

Question 4

Define ‘community’

Answer 4

All the populations of different species in an area at a particular time (only includes the living inhabitants)

Question 5

Define ‘biotic’

Answer 5

The living component of an area

Question 6

Define ‘abiotic’

Answer 6

A non-living component of the environment

Question 7

Define ‘species’

Answer 7

A group of organisms that are more or less alike and can reproduce fertile offspring in their natural environment; the members of a species share a common gene pool

Question 8

Define ‘reproductive isolation’

Answer 8

A mechanism that prevents gene flow between populations

Question 9

Define ‘gene flow’

Answer 9

The movement of alleles into or out of a population due to migration or transfer of gametes

Question 10

Define ‘allele’

Answer 10

An alternative form of a gene for a particular characteristic

Question 11

Define ‘gamete’

Answer 11

A male or female haploid sex cell that fuses with another gamete to form a diploid zygote

Question 12

Define ‘gene’

Answer 12

A segment of a chromosome that determines a particular inherited characteristic

Question 13

Define ‘zygote’

Answer 13

The diploid cell that is formed when two gametes fuse

Question 14

Define ‘producers’

Answer 14

An autotroph

Question 15

Define ‘autotroph’

Answer 15

An organism that is able to manufacture all of its complex organic compounds from simple inorganic substances

Question 16

Define ‘consumers’

Answer 16

A heterotrophic organism that feeds on other organisms or their wastes or remains

Question 17

Define ‘heterotroph’

Answer 17

Organism that cannot produce all of its complex organic compounds from simple inorganic substances and relies on other organisms or their products or remains

Question 18

Define ‘decomposer’

Answer 18

An organism that feeds on the dead remains and wastes of other organisms, thus recycling nutrients in the process

Question 19

Define ‘environment’

Answer 19

The sum of all the factors that influence an organism

Question 20

Define ‘resource’

Answer 20

Anything from the environment that an organism uses

Question 21

Define ‘productivity’

Answer 21

The rate of production of organic matter (biomass)

Question 22

Define ‘biomass’

Answer 22

The total mass of organic matter in a community

Question 23

Define ‘chemical bond’

Answer 23

The force that holds atoms together

Question 24

Define ‘succession’

Answer 24

The progression in area over time from pioneer species to a climax community

Question 25

Define ‘climax community’

Answer 25

A community that is stable and has ceased succession

Question 26

Define ‘primary succession’

Answer 26

The initial succession in a barren area, starting with pioneer species

Question 27

Define ‘biodiversity’

Answer 27

The variety of organisms living in a region

Question 28

Define ‘reproductive effort’

Answer 28

The amount of energy that a species puts into producing the next generation compared to the amount of energy expended in maintaining the adult organisms

Question 29

Describe ‘disturbed community’

Answer 29

A community in which the natural balance has been upset by, for example, the removal of a part of it

Question 30

Define ‘r-selected’

Answer 30

A species whose growth in the early stages is only limited by the rate of reproduction (r) and therefore is usually extremely rapid. These species tend to have a short life span, produce many offspring that are small in size, and parents do not nurture their offspring

Question 31

Define ‘opportunistic species’

Answer 31

A species that has a short life span and high reproductive effort. It will increase its population numbers rapidly when conditions are favourable.

Question 32

Define ‘k-selected’

Answer 32

A species whose growth is influenced by environmental factors that determine the maximum size of the population or the carrying capacity (k) of the habitat. These species tend to live in stable environments, have a long life span, reproduce slowly, produce few offspring that are large in size, and parents tend to nurture their offspring

Question 33

Define ‘equilibrium species’

Answer 33

A stable species that is well established in a community. Usually long-lived.

Question 34

Define ‘habitat’

Answer 34

The place where an organism lives

Question 35

Define ‘genetic variability’

Answer 35

Genetic variability is either the presence of, or the generation of, genetic differences

Question 36

Define ‘natural selection’

Answer 36

A process in which those individuals in a population who are better suited to the environment tend to survive and contribute more genes to the next generation, thus influencing the characteristics of future generations

Question 37

Define ‘geographical separation’

Answer 37

The separation of two populations by a geographical barrier that may lead to speciation

Question 38

Define ‘speciation’

Answer 38

The formation of two or more species from one

Question 39

Define ‘interbreeding’

Answer 39

To breed with individuals of another species, subspecies, or variety

Question 40

Define ‘extinction’

Answer 40

The death and disappearance of all the populations of a species

Question 41

Define ‘biosphere’

Answer 41

The portion of the Earth that is inhabited by organisms

Question 42

Define ‘carrying capacity’

Answer 42

The maximum number of organisms that a habitat can support