4ab - environment + feeding relations

Question 1

ecosystems defo?

Answer 1

distinct, self-supporting system of living organisms interacting with each other, and their physical environment.

Question 2

what are ecosystems made up of?

Answer 2

community + habitat

Question 3

community defo and what are they made up of?

Answer 3

the living biotic part

includes different organisms, living in the same habitat

made up of: sum of populations

Question 4

population defo?

Answer 4

number of individuals of the same species in a habitat.

Question 5

habitat defo?

Answer 5

non living part/abiotic/physical

where orgs live

has all things orgs need to survive, incl. O2, H20, light and shelter

Question 6

what does a habitat contain?

Answer 6

producers = makes own food, autotrophs, supply energy for ecosystem, photosynthesising plants

consumers = animals that eat plants/other animals

decomposers = bacteria and fungi which break down dead material to recylce nutrients (saphrotrophic nutrition).

Question 7

ecosystems final equation components?

Answer 7

= community + habitat
= sum of populations + abiotic feautures + consumers + producers + decomposers

Question 8

measuring biodiversity - where…

Answer 8

biotic and abiotic factors affect population sizes and distribution of species within ecosystems

Question 9

abiotic factors examples? (7)

Answer 9

• sunlight
• temp
• pH
• water
• minerals
• soil type
• salinity

Question 10

biotic factor examples (4)

Answer 10

• food availability
• predators
• competition from other organisms
• infection from pathogens

Question 11

how to measure biodiversity

Answer 11

distribution & population size

Question 12

what do they measure BD? and what are they?

Answer 12

quadrats

metal 1m^2 grid w smaller squares

Question 13

method to measure BD with random sampling

Answer 13

1. mark a 10m x 10m area, using large tape measures, in multiple locations.
2. use the random # generator, to generate random coords
3. place the bottom left corner of your quadrat at the coordinate
4. count the # of species in the quadrat & record in the table
5. repeat steps 2-4, for 10 readings

6.calculate the mean # of species, per quadrat for each location.

estimated total population = average # of species x total area (100m2)
(species per m2)

Question 14

example of low BD

Answer 14

field of wheat, low # species = variety of species is low

Question 15

example of high BD

Answer 15

rainforest, many specie = variety of species is large

Question 16

importance of BD?

Answer 16

ecosystems are more stable and more able to sustain changes in environment, incl natural disasters.

human impacts on planet leads to low BD (deforestation, global warming, pollution)

Question 17

measuring the distribution of BD, systematicall systematically

Answer 17

quadrat + transect

transect = line where readings are taken along, and where quadrat is placed along.

Question 18

method of measuring the distribution of BD, systematicall systematically

Answer 18

1. lay transect along path
2. place quadrat every metre (in equal increments), along the transect.
3. look at:
   a) one species & see how it changes along the transect.
   b) number of different species in each quadrat.
   c) counting smaller organisms, percentage of quadrat covered
4. each quadrat, includes abiotic factors, such as light intensity + temp + pH
5. plot graphs against a particular abiotic factor for each quadrat = correlation.

Question 19

what is biodiversity? defo

Answer 19

measure of variety of different species in an ecosystem

Question 20

what do food chains show?

Answer 20

what eats what

passage of energy from Sun transfers from orgs

Question 21

diff consumers in FCS?

Answer 21

herbivores: animals that just eat plants

carnivores: animals that just eat other animals

Question 22

food chain order

Answer 22

producers –> primary consumer —> secondary consumers –> top predators

(DIFF TROPHIC LEVELS)

Question 23

diff ecological pyramids?

Answer 23

1. numbers
2. biomass
3. energy transfers

Question 24

pyramids of numbers

Answer 24

• size of each block = number of organisms

Question 25

pyramids of biomass

Answer 25

biomass: total amount of living material in an organism

biomass = number x dry mass
= number x (was w/o water)

Question 26

pyramids of energy transfer

Answer 26

shows how energy is passed between levels

all orgs use energy up via MRSCGREN, so not ALL energy passes on.

e.g animal can;t digest/absorb some and egests some.

only about 10% energy passed on = limits number trophic levels in a FC = classic pyramid shape.

20,000 J –> 2,000 J

Question 27

why is energy lost from producer to primary consumer?

Answer 27

• not all producer is eaten
• energy lost to respiration/jeat loss
• some die/decompose
• energy lost as excretion
• some producer egested