Ecosystems

Question 1

define abiotic factor

Answer 1

non living components of an ecosystem that affects other living organisms

Question 2

define biotic factors

Answer 2

environmental factors associated with the living organisms in an ecosystem that affects each other

Question 3

define ecosystems

Answer 3

a community of animals , plants and bacteria interrelated with the physical and chemical environment

Question 4

what are the components of an ecosystem

Answer 4

habitat- the place where an organism lives

population- all of the organisms of one species ,who live in the same place at the same time and who breed together

community- all the populations of different species , who live in the same place at the same time , and who can interact with each other

Question 5

factors effecting ecosystems

- biotic factors

Answer 5

• producers, plants which supply chemical energy to all other organisms
• consumers, primary consumers are herbivores , which feed on plants , and which are eaten by carnivorous secondary consumers . these in turn are eaten by carnivorous tertiary consumers
• decomposers , feed on waste material or dead organisms

Question 6

what are the three types of changes in ecosystems that effect population size

Answer 6

cyclic changes
directional changes
unpredictable changes

Question 7

describe cyclic changes

Answer 7

these changes repeat themselves in a rhythm

[for example movement of tides and changes in day length are cyclic . the way in which predator and prey species fluctuates is cyclic

Question 8

describe directional changes

Answer 8

theses changes are not cyclic . they go in one direction , and tend to last longer than the lifetime of organisms within the ecosystem . within such change, particular variables continue to increase or decrease

examples include the deposition of silt in an estuary or the erosion of coastline

Question 9

describe unpredictable changes

Answer 9

these have no rhythm and no constant direction.

for example such changes may include the effects of lightning or hurricanes

Question 10

define biomass transfer

Answer 10

transfer of biomass from one trophic level to another

Question 11

define trophic level

Answer 11

the level at which an organism feeds in a food chain

Question 12

explain what happens to the energy reaching the producers that is not converted into growth

Answer 12

reflected off the plant
not hitting photosynthesis parts of the plants
different wavelengths

Question 13

name one decomposer

Answer 13

bacteria

Question 14

state three ways in which energy is transferred from primary consumers to decomposers

Answer 14

death
egestion
excretion

Question 15

the role of pioneer species

Answer 15

• development of soil
• changes in soil PH
• hold more water
• release minerals and nutrients