Chapter 3

Question 1

Define ecosystem

Answer 1

An interacting community of populations of organisms and the physical environment in which they live

Question 2

Define environment

Answer 2

Abiotic and biotic factors of an area

Question 3

Define abiotic

Answer 3

The non-living components of an ecosystem (light intensity, temperature, pH of soil, salinity, water availability)

Question 4

Define biotic

Answer 4

The living components of an ecosystem (parasites, competitors)

Question 5

Define community

Answer 5

The sum of the different species inhabiting a particular habitat at one time

Question 6

Define habit

Answer 6

An area or environment where an individual or species lives within an ecosystem

Question 7

Define biosphere

Answer 7

Sum of all the ecosystems across the world

Question 8

Define biome

Answer 8

Main categories of ecosystems across a large geographical area

Question 9

What are the four main types of terrestrial biomes

Answer 9

Tropical rainforests, deserts, grasslands and tundras

Question 10

What are terrestrial biomes classified by

Answer 10

Vegetation types, climate, topography and soil type

Question 11

define topography

Answer 11

The composition of the natural and man made features of an area

Question 12

What factors influence the kind of organisms that inhabit an aquatic biome

Answer 12

How permanent the body of water is, salinity, depth and nutrient availability

Question 13

Three examples of moving aquatic biome

Answer 13

Oceans, bays, rivers

Question 14

What are some examples of still aquatic biomes

Answer 14

Lakes, ponds and swamps

Question 15

Population

Answer 15

A group of individuals belonging to the same species living in a particular area at the same time

Question 16

Limiting factors

Answer 16

An element of the environment that restricts the survival of an organism to a region. Are usually expressed as a lack of a particular resource eg, food, competition, altitude etc)

Question 17

Tolerance range

Answer 17

a set of abiotic conditions in which an organism functions at its optimal

Question 18

Zone of intolerance

Answer 18

The organism cannot survive

Question 19

Dominant species

Answer 19

The most common species in a particular ecosystem (eg mangrove swamp, spinifex grassland, coral reefs)

Question 20

Ecological niches

Answer 20

The way in which species function within their environment. (Eg, time they feed, what they feed on, where they live)

Question 21

what is a Fundamental (potential) niche

Answer 21

The idea niche a species would occupy if there were no predators, competitors or parasites

Question 22

Realised (actual) niche

Answer 22

The actual niche that a species inhabits

Question 23

Resource partitioning

Answer 23

organisms can’t feed on the same food at the same time. Reduces competition

Question 24

Example of resource partitioning

Answer 24

Different forest birds feed at vary heights, some animals feed at night, others during day.

Question 25

Competitive exclusion principle

Answer 25

Occurs when 2 species compete for the same resource and cant coexist in the same community as one will obtain the resource more effectively and drive the other to extinction

Question 26

Example of competitive exclusion principle

Answer 26

When a lab test was conducted between P. aurelia and P. caudatum, P. Aurelia was able to obtain food more effectively, reproduce faster and drive P. caudatum to extinction

Question 27

Define competitors

Answer 27

Competition within and between a species

Question 28

Define collaborator

Answer 28

Members of a group that help each other catch prey

Question 29

Intraspecific interaction

Answer 29

Relationships between members of the same species

Question 30

Interspecific interaction

Answer 30

Relationship between members of the different species

Question 31

How can the numbers of prey effect the numbers of predators

Answer 31

With increased availability of prey, the number of predators can increase (but will always stay less than prey). When the prey population decreases, there is intraspecific competition between predators. They then turn to alternative prey, allowing the original prey to repopulate

Question 32

Symbiosis

Answer 32

Describes the relationship in which individuals of 2 or more different species live together and at least 1 of the species benefits

Question 33

What are the three main types of symbiosis

Answer 33

Parasitism, mutualism and commensalism

Question 34

Define parasitism

Answer 34

When an organism lives on or in another organism (eg bacteria, virus, fungi. Native mistletoe is a parasitic plant to eucalyptus trees )

Question 35

Mutualism

Answer 35

When the organisms work together and share the same ecosystem. Both benefit and neither is harmed. (Eg pistol shrimp and the goby fish. Shrimp is blind, fish acts as eyes and uses burrow)

Question 36

Commensalism

Answer 36

A one sided interaction between species, only one benefits but the other is unaffected (eg, remora fish and sharks. Fish gets a free ride and leftovers)

Question 37

Keystone species

Answer 37

A species of low population that is seen to have a large influence over lower trophic levels to allow the co existence of other species in a particular area

Question 38

Example of keystone species

Answer 38

The purple sea star is a natural predator of mussels. When sea starts are removed, the mussel population increases. The mussels then displace other organisms. The diversity of invertebrates and algae decreased. The predator allowed the coexistence of other species with the same requirements for food + space

Question 39

Zones of physiological stress

Answer 39

an organism can grow but the conditions are not ideal for survival

Question 40

define dichotomous key

Answer 40

Classification system where each branch has two options