Ch. 4 Definitions (Ecology)

Question 1

Species

Answer 1

A group of organisms that can potentially interbreed and produce fertile offspring.

Question 2

Population

Answer 2

A group of organisms of the same species that live in a particular area at the same time.

Question 3

Community

Answer 3

A group of populations living and interacting in a particular area.

Question 4

Ecosystem

Answer 4

A community and its abiotic environment.

Question 5

Abiotic factors:

Answer 5

Non-living factors, such as pH, salinity, wind speed, type of soil, etc.

Question 6

Biotic factors:

Answer 6

Living factors in an ecosystem, such as the plants and animals.

Question 7

Autotrophic

Answer 7

a mode of nutrition which involves the organism making organic molecules using the abiotic environment

(‘self-nutrition’ [direct meaning])

Note: I would say ‘autotrophic’ describes organisms using this mode of nutrition, while the mode of nutrition itself is ‘autotrophy’.

Question 8

Heterotrophic

Answer 8

a mode of nutrition in which organisms obtain organic molecules from other organisms.

(‘other-nutrition’)

See autotrophic card (heterotrophic vs. heterotrophy)

Question 9

Mixotrophs

Answer 9

organisms which use both autotrophic and heterotrophic modes of nutrition.

Question 10

Ingestion

Answer 10

the taking in of a substance (be it solid or liquid food, medication, toxic substances or indigestible materials)

Question 11

Consumers

Answer 11

organisms that gain nutrients by feeding on other organisms using ingestion or absorption.

Question 12

How to define ‘herbivore’, ‘carnivore’, ‘primary producer’, etc.?

Answer 12

With reference to where their food is in trophic levels, e.g.

Herbivores are consumers who feed solely on producers.
Primary consumers feed on producers.
Secondary consumers feed on primary consumers
Tertiary consumers feed on secondary consumers.
Carnivores are consumers who feed solely on other consumers.

Question 13

Detritivores

Answer 13

organisms that gain nutrients by feeding on dead organic material and breaking it into smaller organic molecules VIA INTERNAL DIGESTION

Question 14

Internal digestion

Answer 14

the process by which an organism digests its food inside of its body, usually with the aid of a digestive tract.

Question 15

Saprotrophs

Answer 15

organisms that get their nutrients by secreting digestive enzymes into their environment to break down organic debris around them.

Question 16

External digestion or extracellular digestion

Answer 16

the process by which organisms secrete enzymes into their environment to break down organic debris around them.

Question 17

Ecology

Answer 17

the branch of biology where scientists study ecosystems and the interactions of the biotic and abiotic factors.

Question 18

Symbiosis

Answer 18

‘living together’ - mutualistic, commensalistic, or parasitic interactions between populations

Question 19

Mutualism

Answer 19

symbiotic relationship where both organisms benefit.

Question 20

Commensalism

Answer 20

symbiotic relationship where one organism benefits and the other is unaffected.

Question 21

Parasitism

Answer 21

symbiotic relationship where one organism benefits and the other is harmed.

Question 22

Nutrient cycling

Answer 22

Movement of organic molecules and minerals through the food chain and back into the soil where they can be taken up by plants to re-enter the food chain.

Question 23

mesocosm

Answer 23

tool used to model ecosystems in order to monitor and evaluate variables.

Question 24

Chi squared

Answer 24

statistical test: are two variables (in biology, two populations) associated (each affects the other, e.g. they are dependent on one another) or not?

Used to analyse categorical data

Question 25

Null hypothesis

Answer 25

Hypothesis that states there is no relationship between the variables being investigated, used in chi-squared tests

Question 26

ecological frequency

Answer 26

Number of times a plant species occurs in a given number of quadrats. Frequency is usually expressed as a percentage and is sometimes called a Frequency Index.

Question 27

quadrat

Answer 27

a tool used to measure population distribution in a given area. It is often made in a square shape.

Basically a square grid/frame, you put it on the ground and count the number of plants/animals/etc. inside it

Question 28

food chain

Answer 28

model that shows how nutrients and energy are passed from producer to primary consumer, then secondary consumer, and so on.

It clearly shows how each organism in the chain gets its food as well as the direction the energy flows through the chain.

Question 29

Trophic level

Answer 29

the position of an organism in a food chain (where the producer belongs to trophic level 1)

Question 30

Biomass

Answer 30

mass of dried organic material which can be used as fuel (energy source; not literal combustion-based fuel) in an ecosystem

expressed in terms of dry weight per unit area.

Question 31

Stomata

Answer 31

pores found on the underside of leaves which allow for gas exchange.

Question 32

Anaerobic/anoxic

Answer 32

Without oxygen

Question 33

Methanogenic archaeans

Answer 33

bacteria that are found in several anoxic environments and produce methane as part of the carbon cycle.

tl;dr: bacteria that produce methane

Question 34

Ruminants

Answer 34

mammals that have a mutualistic relationship with methanogenic archaeans that help them to digest cellulose from the cell walls in the plants they eat. This creates methane, which is released as gas from the mammal.

Question 35

Anything ending in ‘-genesis’:

Answer 35

The production of something.

E.g. acetogenesis = produce acetate, acidogenesis = produce acids, methanogenesis = produce methane

Question 36

Peat

Answer 36

partially digested organic matter that forms in acidic, water-saturated soil. Can be gradually compressed into coal.

Question 37

Fossil fuels

Answer 37

organic material that has been compressed over time, to form coal, oil and gas.

Question 38

Lithification

Answer 38

the process of compressing organic matter over a long period of time until it becomes rock.

E.g. shells -> limestone

Question 39

Reservoir/sink:

Answer 39

a place where a certain element, such as carbon, has accumulated or pooled.

Also, known as a sink when discussing nutrient cycling.

Question 40

Flux

Answer 40

process that moves an element from one reservoir or sink to another.

Question 41

Lithosphere

Answer 41

the portion of the Earth that consists of the crust and upper mantle.

Question 42

Hydrosphere

Answer 42

the portion of the Earth that consists of water including oceans, lakes, ponds and rivers.

Question 43

Biota

Answer 43

the portion of the Earth that consists of the living organisms.

Question 44

Atmosphere

Answer 44

the layer of gases surrounding the Earth.

Question 45

Greenhouse gases

Answer 45

gases found in the atmosphere such as water vapour, carbon dioxide, methane and nitrous oxides, that contribute to the greenhouse effect.

Question 46

Radiation

Answer 46

energy that may be a subatomic particle, for example an electron (gamma rays) or in the form of an electromagnetic wave, for example ultraviolet radiation.

Question 47

Solar radiation

Answer 47

energy from the sun that comes in the form of electromagnetic waves. This includes many types of waves such as visible light or ultraviolet light.

Question 48

Ozone layer

Answer 48

layer of the Earth’s atmosphere that protects the Earth from ultraviolet radiation coming from the sun. It is not considered a greenhouse gas because it does not absorb longwave radiation.

Question 49

UV/ultraviolet radiation

Answer 49

a type of shortwave radiation coming from the sun, but is filtered out by the ozone layer

Question 50

Long-wave/long-wavelength radiation

Answer 50

infrared light, a type of radiation that is emitted from the Earth and its atmosphere. Examples include, microwaves and radiowaves.

Heats things up (I think).

Question 51

Short-wavelength radiation

Answer 51

this type of radiation comes from the sun in the form of visible light and ultraviolet light. It is absorbed by the Earth and re-emitted as long-wavelength radiation.

Question 52

Climate

Answer 52

long-term weather patterns in an area or region.

Question 53

Climate change

Answer 53

changes in the long-term weather patterns in an area or region due to the intensified greenhouse effect.

Question 54

Precautionary principle/burden of proof

Answer 54

The principle stating that even without concrete evidence of a causal relationship, precautionary measures should be taken to ensure that humans are not causing harm to the environment or to human health.

Basically, if you’re not sure, take the safe option.

Question 55

Coral reefs

Answer 55

a ridge in the ocean where living coral polyps attach and secrete calcium carbonate.

Coral reefs are typically very diverse places found in warm shallow waters.

Question 56

Ocean acidification

Answer 56

drop in pH of the ocean due to the absorption of carbon dioxide, which forms carbonic acid.

The H+ ions become dissociated from carbonic acid causing the water to become acidic.

Question 57

Calcification

Answer 57

the process used by molluscs, crustaceans, and corals to build their shells and exoskeletons using calcium carbonate.

(Probably an arrow in the carbon cycle, although I don’t know exactly where.)