Unit 13.4-5 : Energy Transfers And Nitrogen Cycles Flashcards
(29 cards)
Autotrophic organisms
Producers- photosynthetic plants
Build up organic compound from (dna) simple molecules
Heterotrophic organisms
Consumers- rely on external source of organic compound
E.g. animals
Saprobionts
1)Bacteria/fung
2)break down polypeptides into amino acid and absorb the nitrates
3)decomposers
What do the arrows represent in a food chain?
Energy transfer
Food chains VS food webs
1)Food chains show feeding relationship
2)interrelationship between food chains
3)food chains do not occur in isolation
Dry mass vs fresh mass
-Dead / Living
-Difficult to assess/ easier
-Small sample / water content varies
-Unreliable (unethical to collect sample) / unreliable due to VARYING water content
What happens during each tropic level? Define tropic level
-stage of an organism in a food chain
-energy is lost
Why the light is not all absorbed by sun. (4)
- Some of light energy is reflected
- Some light energy is absorbed by gases in atmosphere
3 light energy in wrong wavelength - Some light energy does not strike chlorophyll
GPP
R
NPP
Rate of photosynthesis
Respiratory losses
Energy stored or formed in new biomass
Define biomass
Total organic material given at a specific time / area
NPP = GPP — R
What are some large energy losses?
- Large amount of animal/plant indigestible and lost from faeces
- Not all plant may be eaten
- Energy lost in excretion as urine
- Energy lost in respiration as heat
Explain why an increase in biomass can be taken as a product of net primary productivtiy.(2)
1.represents dry mass
2. NPP = GPP - R
Determine the dry mass of a plant/ animal.(2)
1)Heat at 100 to evaporate h20
2)Weight until no further change in mass
Dry mass over fresh mass
1.Water content is variable
2.will not affect dry mass
Example of increasing energy transfer rate.(5)
1.restricting movement so less respiratory losses as less muscle contraction
2.Keeping animals indoors to reduce heat loss
3.selective breeding/ genetically breedigng
4.slaughtered before reaching adulthood so more energy transferred to biomass
5.feeding nutrients
NC: describe process of nitrifyication
1)organisms 2)reaction
1)nitrifying bacteria
2) ammonia nitrites to nitrates
3) nh3 > No2 > no3
NC: describe process of denitrification
1) microorganisms 2) reaction
1)denitrifying bacteria
2)No3- to N2
NC: describe nitrogen fixation
1)microorganisms 2)reaction
1)nitrogen fixing bacteria
2) nitrogen to ammonia
NC: decomposition
1)organisms 2)reaction
1)saprobionta
2)nitrog compounds to ammonia
NC: nitrogen molecules and importance
1)aminoacids
2)proteins
3)nucleic acids- dna rna
4)adp
5)atp
6)nadp
NC: Describe how the action of microorganisms in soil produces a source of nitrates.(5)
1) aminoacids /DNA/converted into ammonia
2)saprobionts
3)ammonia into nitrite to nitrate then
5)by nitrifying bacteria
6)n2to ammonia by nitrogen fixing bacteria
NC: How could a farmer make farmland more fertile?(4)
1)add nh3 fertiliser
2) crop rotation with legumes
3)drain and derate soil
NC: phosphate cycle (5) link with growth
1)saprobionts decompose
2) phospholipids rna, dna, atp, from dead organisms into po4- ions
3)po4- found in bones
4) phosphate ions transported by rivers and oceans
5)form sedimentary rocks
Environment impact of using fertilizers(3) (GRowth)
-contain ?
Po4- NO4- K+
1)reduces species diversity
2)crops removed,less decomposition, less nitrates returned to soil
3)leaching
