Module 6.5

Question 1

What is the importance of nitoirgen in the environment ?
how do plants and animals ge it in this way and why ?

Answer 1

78% nitorgen gas however , need cycle because plants and animals CANNOT OBTIN nitrognen through gas exchnage , this is becaue N2 has a triple bond .

Question 2

What is needed to convert nitorgen gas into nitorgen containing substances ?

Answer 2

Micorganisms , so that plants can absorb it b active transport and animals can absorb b eating and digesting plants .

Question 3

What is the importance of nitogen in animals

Answer 3

poreins , atp and nucleic acids .

Question 4

nitrogen cycle can be split into four different stages ,what are they ?

Answer 4

1.ammonification
2.nitrification
3.nitrogen fixation
4.denitrification .

Question 5

part one

Answer 5

START IN NITROGEN IN ATMOSPHERE .
-Nitrogen-fixing (converting n2 ) into ntirogen cntaining compounds .n

-This can be done directl in plants , in legumes , root nodules .

Question 6

why can this be done directly in root nodules ?

Answer 6

as root nodueles have bacteira , this bacteira is able to convert inot n2 , gas into ammonium / nitrates , this is the direct route .

Question 7

HOWEVER , not all plants have root nodues ,s o hwo do they do it >

Answer 7

root nodules can only be found in leguminous pnts - these can direcntl convert into n2 compounds in plants due to SYMBIOTIIC RELTIONSHIP (both plant and bacteria are gaining benefits ) .

Question 8

check star 2

Answer 8

alternative if it is not a leguminous plant ( alone ) bean plants .

-There is nitrogen fixining bacteira that occurs in the soil .
-These bactria convert N2 into ammonium known as AMMONIFICATION (as we create ammonia )

Question 9

star three

Answer 9

that ammonia needs to be nitrfied and go thru the process of nitrification before it can be absorbedby the plant . THIS HPPENS INT WO WAYS .

Question 10

star four way one

Answer 10

nitrifying bacteria , happen 2 stages

ammonium nh4+ –> nitriles (no2-)

Question 11

STAR FIVE way two

Answer 11

e nirifying bacteria in the soil which are able to convert to nitriles into nitrates

STAR FOUR AND STAR FIVE ARE NITRFICIATIONS TEPS .

Question 12

star 6 nitrates (NO3-)

Answer 12

could be dissovled within the water , within the soil are able ot be abdorbed into the plant b active tranpsort .
-and they can be asimialted inot hte cell and they would be used to creare amino acids , ATP and DNA .

Question 13

star 7

Answer 13

once in the plants , animals (eat the plants ) and nitrates get into the animals .

Question 14

star 8

Answer 14

animals will produce , waste that constnt ammonia they will also eventully die as will the plants .
-when animals and plants die –> porteins and dna within themsleves all contain n2

-Digest porteins into other nitrogen containing compounds .

Question 15

star nine

Answer 15

also ammonification as waste are able to be converted into ammonia and portein cucles round and round

Question 16

star ten

Answer 16

also denitifying bcteira are bale to converte nitaes (no3-0 By DENITIFYING BACTERI .

Question 17

what is an ecosytem

Answer 17

a community of animals , plants and bcteira inerrleated witht he phsycial and chemical neviornemnt.

Question 18

abiotic factors

Answer 18

non living components of an ecoystem tht affect other living organisms .

Question 19

bioic faxcors

Answer 19

environmental factors associted with living organissms in an eocysem =th ffect eachother , predation , disease .

Question 20

componentd of an ecosytem and their meaning

Answer 20

HABITAT - the place where an organism lives.
POPULATION - all organisms of one species who live in the same place at the saeme time and can canbreed together .
COMMUNITY - all the population of diferent species who live int he same places at the saeme time , nd who can itneract with eachotehr .

Question 21

what is a niche ?

Answer 21

the role of each species in an ecoystem .
-difficult to defien niche entirelybecause each organisms interacts with both living nd non-liiving things .

impossible to dra line of ecosytems . but closed eseir to udnersand .

Question 22

give a couple of examples of biotic factors (1)

Answer 22

-producers plants ( and some photosyntheitc bactiera ) , which supply chemical energy to all other organsims .
-consumer (primar consumer ( are herbivores ,w hich feed on palns ,a nd which are eaten by crnivorous secondary consumers . Thee in turn are eenby carnivorous tertiary consumers .

Question 23

give a couple of exmples of biotic factors (2)

Answer 23

decomposers (bacteria fungi and some aniamls ) feed onw ste mterial or dead organisms .

-because these components of the ecostem reqruie thier own source o material and egergy , they can affect other organisms’ food uspply . They can also be resposnible for predation and disease .

Question 24

give a couple examples of abitoic factors

Answer 24

-describe the effect of the non-living componens of an ecosytems . Ph relatie humdiity temperatures and the cocnentration of polluatns are all examples .

-these can vary in space and time ,s cuh fcors could also include disturbance to he ecyosyem by other ctors such as turblence an dstorms .

Question 25

give a couple of abiotic factors (2)

Answer 25

abitoic factors may also be infleucned by the bitioic components of the ecoysem .
-For example , in a rainforest , forest canop infleucnes the temperture and huidity of the ecosytem .

Question 26

abiotic curve shown in figure 2 , explain

Answer 26

a generalisedcurve deplicing he efffect of an abitoic facor on an organisms activit .
-the abitioic factor could be PH tempeature or any varibale tha has some sore ot optimum level and where there are lethal levels at both extremes ..

Question 27

what haooens when there is not a lethal leel at both extremes ?

Answer 27

an organisms resposnes plotted differnl ,, fro exmple at low elvels of pollutants ,a norganisms may survive without any detrimental effect , but a high level sthe pollutants maybe lethal .

Question 28

ecosytems are dynamic why ?

Answer 28

because hey change nonlviign eleemnts change and lviign elemnts forwo and ide .

ecoystem lving thing inerct with environemnt , any small chances can effect one nother for example . predtors poplation size oes up , prey population fo down , ntirogen levels ins oil affect popualtion sies of plns .

-ntiogen fixiing palnts row sucessufly in nw2 eficien tsoil btu affect htie renviornment

Question 29

one type of change in ecoystem affecting population size CYCLIC CHANGES

Answer 29

these changes repat themselves ina rhythm , for example movmemnts of tifes and changes in day length are cyclic .
-The way in which predaor and preys pecies fluctuate is cclic .

Question 30

second tyoe if change in ecoystem direcrional changes

Answer 30

these changes are not cyclic heyg o ino ne directiona nd tend to last longer than the lifetime of orgasims withint he eocystem .

-woton such change , particualr variables continue to incrase or decrease ( examples incldue t=depostin f silt in an estuary )

Question 31

third type of change in ecoystem - unpredictbale / errtic changes

Answer 31

these have no rhythm and no constant direction . For example , such changes , may incldue the effects of lightning or hrurricanrs .

-living thing respon to changes ine coystme so small mammals mayhiebrnte due to rhyyhtmc fo rexample .

Question 32

Biomass transfer

Answer 32

transfer of biomass from one trophic levels to another .

Question 33

trophic level

Answer 33

the level at which na organisms feeds in a food chain

Question 34

energy and materials in an ecosytems

Answer 34

materials re constanlt recyled within an ecoystme nutrient cycles sucha s the nitorgen cycle and crbon cycle re good eamples energy is not recyled it lows throuhh the ecosytem.

Question 35

how is energy interchanged in plnts ?

Answer 35

Eneergy captured in plants in photosntehssis to produce organic molecules like glucose from warer and carbondioxide .
-such energyis rlesed from glucose during respiration .0
-

Question 36

what are the products of photosyntheiss used for >

Answer 36

-they are not onl used immdeiately for resprition , but incorporated into tissued an organs (celluose - th ebuilding block of plant cell alls - is made up of large number of glucose moelcules )>

-mineral ions are also absrobed through plant root .

Question 37

what happens to the plants biomass and how doe sthe biomass transfer between all the componenet s

Answer 37

-together , the organic components (such as glucose moelcue s) and inorganic components (such as mineral ions but exclding water ) .
-of the plan make up its biomass , so whena lant is eaten , its biomass is consumed by a priamry consumer .

Question 38

how is changes in biomss tracked .

Answer 38

topric levels .

Question 39

give me one reason why biomass is lost from the trophic elvel

Answer 39

t each trophic level , living organisms need energy to carry out life processes .
-respiration , releases energy from organic moelcules such a s glcuose .
-some of thisw enegry is evenutally convered to hea and materials are lost in carbondxoide and water.

Question 40

another reason wh biomass i slost at ech level .

Answer 40

-biomass is also ost froma food chain in dead organisms and waste material , which is then only avilable to decomposers sucha s fungi and bacteria .
-this waste material also includes parts of nimals nad plan that cannotbe digested byc onsumers such as bones and hair .

Question 41

Where is biomss less ?

Answer 41

t higher levels of the food chain . When the orgaisms in a food chaina re baout the sme size this means there will be ewer consumers at hhigher levels .

-ecologists draw a pyramid of numbe to represent htis number idea .

-THE ARE , of each bra in the pryamid i propotional to thenumbe rof indivuals an apporximaion for the total bomass at that levels .

-pyramids can be drawn for idnividual food chains . or fo an ecostem as w hole .

Question 42

doe , counting the number of organisms always provide an accurate picture of how much biomass exists at each lrevel >

Answer 42

no , nd a bteer pproch is to draw a pyramid biomass here the area of each bar is proportional to the drymass of all the orgnamisms t that rophic level .

Question 43

how do ecologists obtin dry mass,

Answer 43

organisms put ina n oven at 80 degrees until all the waer int hem has been evaporaed .

-they check this by periodically fidning the mass of the organisms .
-pobnce the mass stops reduing ,t hey can be certain tht all the waer has been removed .

but this is so destrcutvie so wet mss is used .

Question 45

two equatiions tht are used to calculate the biomass transfer ?

Answer 45

page 273 .