6.5-ecosystems :)

Question 1

what is an ecosystem?

Answer 1

any group of living or non living things and the relationships between them.

Question 2

what are the components of an ecosystem?

Answer 2

habitat
population
community

Question 3

what is a population?

Answer 3

all the organisms of 1 species who live in the same place at the same time and breed together.

Question 4

what is a community?

Answer 4

all the populations of different species who live in the same place at the same time and who can interact with eachother.

Question 5

what is the niche of a species?

Answer 5

the role of each species in an ecosystem.

Question 6

what are the biotic factors affecting an ecosystem?

Answer 6

producers
consumers
decomposers

Question 7

how do biotic factors affect ecosystems?

Answer 7

affect other organsisms’ food supplies
predation
disease

Question 8

what are examples of abiotic factors affecting ecosystems?

Answer 8

pH
relative humidity
temperature
pollutant conc

Question 9

what are the 3 types of change in ecosystems?

Answer 9

cyclic
directional
unpredictable

Question 10

what are cyclic changes?

Answer 10

changes that repeat themselves in a rhythm, eg tides

Question 11

what are directional changes?

Answer 11

changes which go in 1 direction+are usually longer lasting than the lifetimes of organisms.

Question 12

what are 2 examples of directional changes?

Answer 12

deposition of silt in an estuary

erosion of a coastline

Question 13

what is a trophic level?

Answer 13

the level at which an organism feeds in a food chain.

Question 14

why is biomass lost at each trophic level?

Answer 14

metabolic processes eg respiration
waste material
parts that can’t be digested

Question 15

ecological efficiency=?

Answer 15

(biomass at higher trophic level/biomass at lower trophic level) x 100

Question 16

what is productivity?

Answer 16

the rate of production of new biomass by producers.

Question 17

what is gross primary productivity?

Answer 17

the rate at which plants convert light energy to chemical energy through photosynthesis

Question 18

get your notes on net primary productivity

Answer 18

do it

Question 19

what are saprotrophs?

Answer 19

organisms that feed on decaying/dead organic matter.

Question 20

what is nitrogen fixation?

Answer 20

when nitrogen gas in the air is converted to useful organic nitrogen compounds

Question 21

chemical symbol for nitrates?

Answer 21

NO3-

Question 22

chemical symbol for nitrites?

Answer 22

NO2-

Question 23

when can nitrogen fixation occur?

Answer 23

lightning
bacteria
haber process

Question 24

what free living bacteria in the soil do nitrogen fixation?

Answer 24

Azotobacter

Question 25

what bacteria that live in root nodules do nitrogen fixation?

Answer 25

Rhizobium

Question 26

how do nitrogen fixing bacteria in nodules work?

Answer 26

use nitrogen reductase to turn n2 into nh4+ which is used by plant

Question 27

what does Nitrobacter bacteria do?

Answer 27

oxidises nitrites to nitrates

Question 28

what does Nitrosomonas bacteria do?

Answer 28

oxidises NH4+ to nitrites

Question 29

what does Azotobacter bacteria do?

Answer 29

nitrogen fixing (lives free in soil)

Question 30

what does Rhizobium bacteria do?

Answer 30

nitrogen fixation in root nodules

Question 31

what are the 4 processes of the nitrogen cycle?

Answer 31

nitrogen fixation nitrification decomposition/ammonification denitrification

Question 32

what are chemoautotrophic bacteria?

Answer 32

bacteria which get their energy not from sunlight but from chemical reactions, eg oxidising NH4+ to NO2- or No2- to N03-.

Question 33

what is nitrification?

Answer 33

oxidation of ammonia or ammonium to nitrite followed by the oxidation of the nitrite to nitrate.

Question 34

what is denitrification?

Answer 34

turning nitrates to nitrogen gas.

Question 35

what part of the nitrogen cycle needs well aerated soils?

Answer 35

nitrification: requires oxygen.

Question 36

what can nitrates be used for in a plant?

Answer 36

making nucleotide bases and amino acids.

Question 37

under what conditions does denitrification take place?

Answer 37

anaerobic, eg waterlogged soils.

Question 38

why does denitrification take place?

Answer 38

no o2: bacteria use nitrates as source of o2, producing n2 and n20.

Question 39

what do aquatic plants use for photosynthesis?

Answer 39

dissolved carbonates.

Question 40

what is a climax community?

Answer 40

the final stable community that exists after the process of succession has occurred.

Question 41

what are pioneer species?

Answer 41

species that begin the process of succession, often colonising an area as the 1st living things there.

Question 42

what is succession?

Answer 42

progressive change in a community of organisms over time.

Question 43

what is primary succession?

Answer 43

development of a community from bare rock.

Question 44

what is a pioneer community?

Answer 44

all the living organisms that occupy an area undergoing primary succession in the beginning stages

Question 45

where does secondary succession take place?

Answer 45

on a previously colonised but disturbed or damaged habitat.

Question 46

what is the sub climax community 9result of deflected succession) called?

Answer 46

plagioclimax

Question 47

what 2 types of data can you collect using a quadrat?

Answer 47

% distribution | abundance (no of individuals)

Question 48

how can you make your quadrat more accurate?

Answer 48

use a point frame

Question 49

what are the 2 types of transect?

Answer 49

line | belt

Question 50

what do you do with a line transect?

Answer 50

make a note of which species is touching it at eregular intervals

Question 51

what do you do with a belt transect?

Answer 51

place quadrat next to it

Question 52

what's an interrupted belt transect?

Answer 52

when you place the quadrat next to it at regular intervals.

Question 53

what is a continuous belt transect?

Answer 53

when you just move the quadrat along the transect.