Ecology - 2.1 Individuals, populations, communities and ecosystems

Question 1

Biosphere

Answer 1

An ecological system composed of individuals, populations, communities and ecosystems

Question 2

Components of the biosphere

Answer 2

• biome
• ecosystem
• community
• population
• individual
• gene

Question 3

Species

Answer 3

A group of organisms that can interbreed and produce fertile offspring (biological species concept)

Question 4

Classification

Answer 4

The systematic arrangement of organisms into groups based on shared characteristics or evolutionary relationships

Question 5

Stages of classification

Answer 5

• domain
• kingdom
• phylum
• class
• order
• family
• genus
• species
  (Do keep penis clean or fanny gets spots)

Question 6

Genus

Answer 6

A taxonomic category ranking below family and above species, containing related species

Question 7

Taxonomist

Answer 7

A scientist who identifies, names and classifies organisms into groups based on shared charactristics

Question 7

Dichotomous key

Answer 7

A tool for identifying organisms using a series of paired, mutually exclusive choices
* series of yes or no questions that divide groups of organisms into smaller and smaller groups

Question 8

DNA Survey

Answer 8

Method of identidying organisms by analysing genetic material

Question 9

DNA Survey stages (6)

Answer 9

• collection
• extraction
• amplification
• sequencing
• analysis
• interpretation

Question 10

Population

Answer 10

A group of organisms of the same species living in the same area at the same time and which are capable of interbreeding

Question 11

Abiotic factor

Answer 11

Non-living physical factors that may influence organisms

Question 12

Abiotic factor examples (name 2)

Answer 12

• Air/water temp.
• Ambient light levels
• Water salinity or turbidity (clarity)
• Soil characteristics

Question 13

Biotic factors

Answer 13

Living components of an ecosystem

Question 14

Biotic factor examples (name 2)

Answer 14

• Food sources
• Predators
• Competitors for the same resources

Question 15

pH

Answer 15

A measure of how acidic or basic a substance is, from 0 to 14

Question 16

Salinity

Answer 16

The concentration of dissolved salts in water, often expressed in parts per thousand

Question 17

Dissolved oxygen

Answer 17

The amount of oxygen gas present in water, crucial for aquatic life
* higher DO = better water quality

Question 18

Soil texture

Answer 18

The relative proportions of sand, silt and clay particles in soil
* affects drainage, fertility and productivity of soils

Question 19

Insolation

Answer 19

The amount of light entering an ecosystem, affecting its temperature and evaporation rate

Question 20

Niche

Answer 20

Particular set of abiotic and biotic conditions upon which an organisation or population depends

Question 21

Ecological niche

Answer 21

The role of a species in an ecosystem

Question 22

Herbivory

Answer 22

The consumption of plant material by animals

Question 23

Predation

Answer 23

An interaction where one organism (predator) kills and eats another (prey)

Question 24

Parasitism

Answer 24

Where one organism benefits at the expense of another typically living on or in it

Question 25

Mutualism

Answer 25

An interaction between two species where both benefit from the relationship

Question 26

Carrying capacity

Answer 26

The maximum population size an environment can sustain indefinitely with available sources

Question 27

Density-dependent factor (2 examples)

Answer 27

An influence on population growth that varies with population density * competition for food becomes more intense as population increases * disease transmission is faster in dense populations because pathogens can spread more easily between individuals

Question 28

Density-independent factor (1 example)

Answer 28

An influence on population growth that is unaffected by population size * natural disasters

Question 29

Two types of carrying capacity graphs

Answer 29

* Exponential growth - J curve * Logistic growth - S curve

Question 30

J curve explained

Answer 30

If there are no limiting factors, the population will continue growing until one is reached

Question 31

S curve explained

Answer 31

When density-dependent limiting factors start to operate, population growth begins to slow

Question 32

4 sections of the S curve

Answer 32

1. Lag phase (low birth rates) 2. Exponential growth phase (growth faster and faster) 3. Transitional phase (growth rate slowes) 4. Stationary phase (growth rate stabilises)

Question 33

Limiting factor

Answer 33

Any resource or condition that restricts the growth, abundance or distribution of an organism or population

Question 34

What has increased our carrying capacity? (2 examples)

Answer 34

* Elimination of natural predators * Technological advances (modern medicine and agriculture)

Question 35

Random sampling

Answer 35

A method of selecting individuals from a population where each has an equal chance of being chosen

Question 36

Systematic sampling

Answer 36

A method of sampling using a fixed, periodic interval to select individuals from a population

Question 37

Transect sampling

Answer 37

A technique for studying organism distribution along a line across an environmental gradient

Question 38

Quadrat sampling

Answer 38

A method using square frames to count organisms in a small representative area

Question 39

Lincoln index

Answer 39

A method for estimating population size using capture-mark-recapture data Pop. size = (MxN)/R

Question 40

Community

Answer 40

A collection of interacting populations within the ecosystem

Question 41

Habitat (how to describe)

Answer 41

The location in which a community species, population or organism lives (description: geographical and physical locations, type of ecosystem)

Question 42

Ecosystem

Answer 42

A community and the physical environment with which it interacts

Question 43

Steady-state ecosystem

Answer 43

A system where inputs and outputs of energy and matter are balanced

Question 44

Keystone species

Answer 44

An organism with a disproportionately large effect on its ecosystem relative to its abundance

Question 45

Biosphere integrity

Answer 45

The functional and genetic diversity of Earth's ecological systems