Environmental studies definitions

Question 1

Define population ecology

Answer 1

Changes in the size or a population and the factors that regulate these changes

Question 2

Define Ecology

Answer 2

The study of the interactions of organisms with their physical and biological environments and how these determine the distribution and make up of populations within an ecosystem

Question 3

Define the Biosphere

Answer 3

The part of the earth where living organisms are found

Question 4

Define an Ecosystem

Answer 4

A group of different species of organisms that interact with each other and the environment

Question 5

Define an organism

Answer 5

An individual form of life, such as a bacterium, protist, fungus, plant or animal, composed of a single cell or a complex of cells that are capable of growing and reproducing.

Question 6

Define a community

Answer 6

A group of different species that inhabit and interact in a particular area.

Question 7

Define a species

Answer 7

A group of closely related organisms that are very similar to each other and are usually capable of interbreeding under natural conditions to produce fertile offspring.

Question 8

Define a population

Answer 8

A group of organisms of the same species that occupy the same area and can breed freely with each other.

Question 9

Define population size

Answer 9

The total number of individuals in a population. It can increase or decrease over time with a change in one or more of the population parameters.

Question 10

Define Natality

Answer 10

Birth rate in animals or the production of seeds in plants

Question 11

Define mortality

Answer 11

The death rate

Question 12

Define Emigration

Answer 12

Individuals leave a population and do not return

Question 13

Define immigration

Answer 13

Individuals move into a population and stay

Question 14

Define migration

Answer 14

The non-permanent movement according to seasonal patterns

Question 15

Define carrying capacity (k)

Answer 15

The maximum number of organisms of a population that the environment can support at a particular time.

Question 16

Define Environmental Resistance

Answer 16

The total number of factors that stop a population from reproducing at its maximum rate.

Question 17

Define limiting factors

Answer 17

The factors that help to regulate the growth of a population. Anything that constrains a population’s size and slows or stops it from growing.

Question 18

What is the formula for mark-recapture?

Answer 18

P= M.C/R
M= Total caught and marked
C: Total caught 2nd
R= Number of marked second

Question 19

What is the formula for the quadrat method?

Answer 19

Total population= Average number in quadrat x size of habitat/ size of quadrat

Question 20

Define Ecological succession

Answer 20

A predictable pattern of gradual change in the types of species in an ecosystem that has previously been uninhabited or following a disturbance.

Question 21

Define predation

Answer 21

The biological interaction where one species, the predator, kills and eats another species, the prey. Predator and prey evolve together and are part of the same environment.

Question 22

Define a food web

Answer 22

An interconnected set of all the food chains in an ecosystem.

Question 23

Define a keystone species

Answer 23

A species that has a disproportionately large effect on its environment relative to its abundance

Question 24

Define competition

Answer 24

When two or more individuals compete for the same resources that are in short supply

Question 25

Define interspecific competition

Answer 25

Competition that occurs between individuals of different species where the ecological niches in the habitat are very similar and overlap to a greater or lesser extent.

Question 26

Define intraspecific competition

Answer 26

Competition between individuals of the same species.

Question 27

Define resource partitioning

Answer 27

The evolutionary process whereby species with similar requirements living in the same habitats have specialised traits that enable them to utilise the resource differently, creating separate niches to reduce interspecific competitions and make co-existence possible.

Question 28

Define an ecological niche

Answer 28

All the resources, biotic and abiotic, necessary for a species to survive and reproduce as well as the role the organism plays in the ecosystem.

Question 29

Define culling

Answer 29

The reduction of a wild animal population by selective slaughter.

Question 30

Define a bioindicator/indicator species

Answer 30

A living organism that gives us an idea of the health of an ecosystem.

Question 31

Define a population pyramid

Answer 31

An age-sex pyramid — a bar graph that shows the composition, by age and sex of a nation’s population at the time of a census.

Question 32

Define an ecological footprint

Answer 32

A measure of the human demand on the Earth’s ecosystems. It represents the amount of biologically productive land and sea area necessary to supply the resources a human population consumes, and to assimilate the waste generated.

Question 33

Define bio capacity

Answer 33

The amount of productive land and water available to produce the resources we use and to absorb the wastes we produce

Question 34

Define sustainable development

Answer 34

The development that meets the needs of the present while not compromising the needs of the future generations

Question 35

Define density dependent factors

Answer 35

Factors which limit the growth of a population as a direct result of the density of the population. The greater the density, the more it limits the population growth

Question 36

Define density independent factors

Answer 36

Factors which limit the size of the population regardless of the population density