ecosystems/ecology

Question 1

definition of habitat

Answer 1

the place where an organism lives

Question 2

definition of community

Answer 2

all the different species in a habitat

Question 3

definition of population

Answer 3

all the organisms of one species in a habitat
eg the human population

Question 4

definition of ecosystem

Answer 4

all the organisms living in a particular area and all of the non-living conditions eg temperature, climate, soil type

Question 5

word meaning ‘non-living’

Answer 5

abiotic
(think A- prefix meaning non- eg Asexual,

Question 6

word meaning ‘living’

Answer 6

biotic

Question 7

what are some abiotic conditions?

Answer 7

NON-LIVING
- toxic chemicals eg fertilisers or pesticides)
- environmental conditions eg soil pH, light intensity, moisture levels, temperature average

Question 8

what are some biotic conditions?

Answer 8

LIVING
- availability of food
- number of predators
- competitions between organisms

Question 9

changes in the environment are caused by a…… and b……. factors

Answer 9

• abiotic
• biotic

Question 10

food chain list:

Answer 10

• producers
• primary consumers
• secondary consumers

Question 11

what are each stage of a food chain called?

Answer 11

a trophic level

Question 12

what is transferred along a food chain?

Answer 12

ENERGY
sun —-> everything else

Question 13

why does most energy not get transferred?

Answer 13

• not all of the organism is eatable
• some parts are not digestible so are lost as faeces
• some are used in life processes eg respiration
• lost as heat/transferred to surroundings

Question 14

what is a quadrat (practical)

Answer 14

a quadrat is a square frame enclosing a known area
(to find the population of a species)

Question 15

mean number of organisms per quadrat equation

Answer 15

mean = total number of organisms/number of quadrats
then to work out population multiply the mean by the total area of the habitat

Question 16

what are belt transects used for?

Answer 16

they are used to find out how organisms are distributed across a habitat

Question 17

what is a pyramid of number

Answer 17

it shows the numbers of each trophic level eg 500 dandelions feeds 100 rabbits which feed 1 fox
(not always in a pyramid shape)

Question 18

what is a pyramid of biomass

Answer 18

this shows the distribution of WEIGHT eg one fox would have a very large biomass but 500 fleas would have much lower
(usually in a pyramid shape)

Question 19

pyramids of energy show

Answer 19

the exchange in energy
- always in a pyramid shape because only 10 percent of energy transfers

Question 20

species in a food web are i……..

Answer 20

interdependent
which means if one species changes, it impacts all the rest

Question 21

what is a food web?

Answer 21

it shows how different food chains are linked
eg if grass –> rabbit —-> fox
if grass —-> cow —–> human
if lots of foxes die, more rabbits survive so more grass is eaten. therefore cows have less food so may die, so humans eat less.
Food webs show other factors that impact food chains, even if they’re not directly part of that chain.