unit 4 topic 5

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Topic 5: On the Wild Side

Photosynthesis:Suggest reasons why 95% of the light hitting the surface of a leaf is not

used by the chloroplasts. (2)*Refection; *incorrect wavelength/colour/

requency; *light doen!t hit the chloroplat/ chlorophyll" it i tran#itted; *light

$eing in e%ce e&g& at #a%& photoynthei o no #ore light can $e ued&

The light dependent reactions

The products of the lightdependent reactions that are used in

the lightindependent reactions are reduced !"#P and.... 'T(

$ygen is produced when water &olecules are split in the process of''

photolyi

hen light is absorbed by chlorophyll it ecites''.electron

#escribe the structures in a chloroplast that are in*ol*ed in the +#reactions (,) The ) reaction involve the *thyla+oid that are

arranged into tac+ o granu#& *The grana are connected $y la#ellae& The

*thyla+oid #e#$rane contain electron carrier" protein and *photoynthetic

pig#ent uch a chlorophyll which are *arranged into

photoyte#/quantao#e; the #e#$rane alo ha *'T(ae/ 'T(ae channel&

-plain how the energy fro& light is &ade a*ailable in "TP &olecules

for the synthesis of organic &aterials. ()

*The light dependent reaction occur in

the thyla+oid *in the granu# in *acceory pig#ent uch a chlorophyll& The

proce $egin when *light energy raie the energy level o two electron o

that they are e%cited" the electron are then *releaed ro# the chlorophyll/

photoyte#& They then travel down the *electron carrier chain" travelling to

each carrier #olecule through a erie o *o%idation and reduction ,redo%-

reaction" releaing energy/ *the electron! energy level all& The energy

releaed i ued to *yntheie 'T( ro# '( and an organic phophate ion

*,phophorylation-; the *en.y#e ynthae/ ynthetae i needed to #a+e the

'T(& *(hotolyi o water produce electron which are ued to replace thoe

lot ro# the chlorophyll&

-plain how oygen is produced during the lightdependent reactions of photosynthesis. (2) 0ing *energy ro# light the *photolyi *o water occur

that produce/releae o%ygen

The light independent reactions/ The Calvin Cycle

/u0P co&bines with carbon dioide in'' The light1independent reaction

o the 2alvin cycle&

R034S2O ''is the en1y&e that catalyses carbon ation.

3arbon ation ta4es place in'.. the tro#a o a chloroplat&

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-plain why the lightindependent stage cannot ta4e place without the

lightdependent stage. (,) 3ecaue the *product o the light1dependent

tage are needed or/ued in the light1independent tage/2alvin cycle& *Thee

product o the light1dependent tage are reduced 6'( and 'T(" *r6'( i ued

in the reduction 7(/car$on dio%ide whilt *'T( i ued a a ource o energy&

Suggest why the de*elop&ent of plants depends on the rate of carbon

ation. (,) *2ar$on 8%ation produce 97( / eq" thi *product i

converted to glucoe/ tarch/ eq& *The ater the 21 i%ation the ater the

glucoe/ tarch production" a the *rate o growth o a plant i dependent on the

rate o 21i%ation" i thi increae o will the *7(( o the crop/plant&

Suggest how "+P &ay be used to synthesise cellulose. (5)

*7')( i a 1glucoe #olecule that are ?oined $y *1@ *glycoidic

$ond in *condenation reaction& *2elluloe i a polyaccharide ,long chain

#olecule- and i an *un$ranched #olecule; each celluloe chain i then ?oined

together in condenation reaction with 1= hydrogen $ond&

The rate of carbon ation is higher at 2563 than at 7863 for each of thesix varieties of maize. Suggest an eplanation for this. (2)*Temperature change affects the kinetic energy/movement of molecules/particles*therefore this effects number of collisions/enzyme-substrate complexes.

lobal ar&ing:Suggest one reason why so&e countries &ay decide to drain their

&arshy peat lands for the production of biofuels. (7)

(roducing 3iouel #ay increae the

*country! inco#e a they can *e%port #ore uel and *i#port le oil/$iouel;

the production o $iouel will alo #a+e *#ore ?o$ availa$le to the general

pu$lic& *3iouel are alo renewa$le wherea *oil uel are 8nite& *0ing

$iouel a an alternative to oil uel will help countrie reach their car$on

target& 0ing peat land will alo #a+e ure that there i *no lo o ar#land"

reducing ethical iue&

Suggest why the continued draining and clearance of peatlands &ay

contribute towards global war&ing e*en though they &ay be used to

produce biofuels. (5) *The co#$ution o $iouel

releae car$on dio%ide that ha $een recently re#oved ro# at#ophere

thereore *there i no ,net- increae in car$on dio%ide in the at#ophere& Thi i

a $ene8t a *car$on dio%ide i a greenhoue ga *that a$or$ inra1red radiation

that ha $een refected ro# the Aarth! urace" *it cannot ecape into pace"

thereore the *car$on dio%ide will caue the #ean urace te#perature o the

Aarth to increae& Bowever" *clearing peat land #ay releae #ore car$on

dio%ide a car$on wa once trapped in peat thouand o year ago; thi

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*caue a net gain o car$on dio%ide in the at#ophere& The proce o clearing

the peat land will *involve #achinery that releae car$on dio%ide; the re#oval

o any peat plant will alo *reduce photoynthei and thu the a#ount o

car$on dio%ide re#oved ro# the at#ophere

Suggest how scientists could use a*ailable data to predict futurecli&ate change.(,) Scientit could *e%trapolate data *to ue or

#odelling/invetigation o correlation to help* provide evidence or glo$al

war#ing& *0ing thi data along with other ource will increae the prediction

relia$ility&

Suggest why so&e scientists &ay not be con*inced that data can be

used to predict future cli&ate change. (,)

3ecaue *there i not enough data to

*con8r# it relia$ility ,*#ay $e place peci8c-& The act that there are *great

fuctuation in #ot cli#ate change data ugget that there i no real trend ,a

cattered- and thu *poor repreentation o raw data& *A scatter of results may

show poor reliability.

4n addition the #ethod o* eti#ating te#perature ro# growth rings of trees i

quetiona$le a *other environ#ental change aCecting the tree are not ta+en

into account&

Scientists ha*e esti&ated that''.. will reduce 3$2 production.

Suggest why the '' &ay be supported by organisations that are

concerned about global war&ing. (5) *The idea will reult

in le carbon dioxide (or methane) *which are both greenhouse gases/ cauethe greenhouse e!ect *as they absorb/ trap heat / infrared/ longer wavelengths

,o radiation- *refected ro# the Aarth& *' reduction in thee gae ,2O- will

lead to a reduced greenhoue eCect" *thi #ean the Aarth! urace

te#perature i le li+ely to rie and that there i a *reduced poi$ility o

cli#ate change which can have eCect uch a the ice cap #elting or crop

ailure&

,4 relevant- *#ethane ha a greater greenhoue eCect than car$on dio%ide&

Suggest why so&e scientists do not agree that a reduction in the use of

fossil fuels will pre*ent further global war&ing. () *4t i clear that car$on dio%ide i produced $y

uing oil uel" however there i *no ,direct- evidence that increaed car$on

dio%ide concentration lead to glo$al war#ing& *2ar$on dio%ide i releaed ro#

other procee uch a repiration and the *re#oval o car$on in+ increae

the concentration too" o reducing oil uel alone will not help& *Other

greenhoue gae alo have a contri$ution" uch a 22" water vapour and

#ethane that co#e ro# *other ource uch a ru#inant ani#al" paddy 8eld"

#elting ice" clearance o peat land& *6atural cycle/event/ pheno#ena #ay alo

$e involved ,in glo$al war#ing- e&g& the un! olar cycle or volcanoe&

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*Avidence or thi co#e ro# the pat and *thi i not an indicator o uture

event/ li#itation o cli#atic #odel& *Scientit #ay alo $e $iaed in their

reearch depending on what country/ co#pany e#ploy the# and their own el1

interet/pro#otion& *We do not yet have an alternative ource o energy that ha

no great pro$le# aociated with it ,i&e& $iouel-&

-plain how te&perature has been &aintained by the presence of

carbon dioide and &ethane in the upper at&osphere. (,)

*7reenhoue gae uch a car$on

dio%ide and/or #ethane *a$or$/trap heat/inrared/long wave radiation *which i

refected/ ,re-radiated ro# the Aarth! urace& *Thee gae prevent

heat/inrared/long wave radiation ro# ecaping& *Thu reulting in te#perature

$eing #aintained higher than they would otherwie $e&

Suggest why te&peratures below 63 or abo*e 8 63 would be

unsuitable for &ost organis&s. (2) *'t DE2 #eta$oli#/ na#ed e%a#ple

top/ i low a *en.y#e are inactive and cell are dirupted" thi #ay $e

*$ecaue o water ree.ing or lower +inetic energy o #olecule in cell& *'$ove

@DE2 en.y#e denature/ change their

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through the proce o e%ternal digetion and then *repiration& *Repiration

releae car$on dio%ide into the at#ophere *or photoynthei& *They alo will

releae #ethane in anaero$ic condition *which i then availa$le a a uel& *The

#icroorgani# the#elve will alo" one day" $e eaten or deco#poe&

-cosyste&s:The dierence between abiotic and biotic factors is that'..$iotic actor

involve organi#/living thing wherea a$iotic are phyical/che#ical/non1living

actor&

" species consists of GG&& individual who can inter$reed to produce ertile

oCpring&

!et pri&ary producti*ity is'..;the rate at which energy i incorporated into

$io#a/ organic #aterial in *producer/ plant" *a there #ay $e loe due to

repiration ,7((1 R-&

The &etabolic process that best describes the process that accounts for

&ost of the dierence between PP and !PP in plants isGG&& Repiration

Suggest two biotic factors that &ay in

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predator/carnivore& ' there i no *need or the tentacle to $e e%poed

*energy will $e conerved and not $e wated&

Suggest adaptations for bacteria li*ing in a cow’s stomach. (,)

The cow"s stomach ha a *low pB/ ,hydrochloric- acid which

nor#ally *detroy $acteria& The to#ach #ay alo have *low/no o%ygen and *othey will have to ue anaero$ic repiration& They will alo have to $e *reitant to

the stomach"s en#ymes" i&e& (roteae" perhap *$y having a cell wall that!

reitant to digetion& *They will alo need to $e adapted to the cow"s body

temperature&

SuccessionSuccession is'.. The equence o change to a co##unity/organi# over a

period o ti#e&

" cli&a co&&unity is'..the 8nal tage/ere/co##unity o ucceion" it i

el1utaining/ ta$le and ha a do#inant pecie

or a ew co1do#inant pecie&

/eproducti*elyisolated populations are'..where *no ,inter-$reeding

$etween ,the population- can ta+e place *$ecaue o a ,geographical/ phyical-

$arrier& (hyical $arrier include the population having *diCerent #ating

$ehaviour" *inco#pati$le genitalia and *each population having a dicrete gene

pool" e&g& retricted gene fow" diCerent #utation/allele&

#escribe what &ight happen if de

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Speciation and e*olution" gene &utation is'.a change in 6' due to the

change/deletion/addition/duplication/u$titution $ae/nucleotide&

enetic di*ersity in a species isGG&&the variety o allele in a gene pool

" gene pool is GGG The total o all the allele in a population&

"llele AreBuency isGGG& The proportion o one allele within a gene

pool/population

-plain why there is li4ely to be a greater genetic di*ersity in a hybrid

plant than in two separate species. (2)

3ecaue there are *diCerent allele in each o the

two population a *each population/ pecie i adapted to living in diCerent

environ#ental condition& *Thi #ean that there will $e diCerent #utation in

each population& *4n a hy$rid the allele o the two diCerent pecie will #i% andhy$rid will receive allele ro# $oth pecie&

Suggest why scientists &ay classify organis&s into subspecies ratherthan two separate species. (2)

*4 the organi# were allowed to inter$reedand could *produce ertile and via$le oCpring they could $e conidered a u$1pecie& *The hy$rid/oCpring can $ower and produce viable seeds.Suggest how the two subspecies de*elop fro& a single ancestral

population use boar. (5) irt a *ew ancetral $oar reach the iland/

ha$itat ro# their original environ#ent" there are now two population that have

*geographical eparation perhap $y the ea or volcanic eruption& *Theepopulation are una$le to inter$reed ,reproductive iolation- and o the *gene

fow $etween the population i retricted/ prevented& *There are only a #all

nu#$er o $oar" on the iland ,ounder eCect-" or $reeding reulting in a *li#ited

variety o allele& *Futation #ay then occur ,*increaing diverity- that are

*acted on $y diCerent environ#ental condition/ election preure that are

unique to the iland ,not ound on #ainland- ie ood" ha$itat; the $oar will *adapt

to $et uit thee $y natural election" *thoe with the #utation are #ore li+ely

to urvive and reproduce& Thee #utation will *change the gene pool a they

arie and poi$ly $eco#e #ore co##on" o the two are now diCerent"

*changing the allele requency& *Thee change will lead to phenotypic/phyiological/phyical/ $ehavioural change; a a reult* allopatric peciation

#ay occur ,can no longer inter$reed-

-plain how the two dierent species of

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plant to *urvive and reproduce" paing on new gene and creating*diCerence $etween gene pool&

Suggest how ecological isolation contributes to speciation. (2)*There #ay $e diCerent condition /environ#ent in each region" i&e& ate#perature diCerence" o *there will $e diCerent election preure& Thegeographical iolation will #ean that the two population are *reproductivelyiolated ro# one another *cauing a retricted gene fow/ eparation o genepool&

Suggest how genetic &utation &ay lead to speciation (2)*Thi will give arie to diCerent allele/ gene pool" leading to *new/diCerentphenotype& Thi new *allele/gene #ay $e advantageou" and o will $e paedonto oCpring; it could alo $e *diadvantageou&

Suggest why interbreeding does not ta4e place between dierent

populations of species. (,) Thee diCerent pecie are reproductively

iolated" #eaning that they #ay have diCerent *$reeding ti#e/ eaon"*courthip $ehaviour/ritual/diplay/colour/ong& *'ny oCpring produced

$etween the pecie #ay $e inertile or not via$le&

Suggest how a distinct species e*ol*es fro& another species. (5)

*7eographical iolation" e&g& a phyical $arrier $etween the

population occur/allopatric peciation" thi #ean there i *reproductive

iolation $etween the population" *there i a retriction o gene fow $etween

$ut not within the population& *Thi create two ha$itat that will contain

diCerent election preure *e&g& diCerent ood ource" or diCerent ha$itat&

*Futation will have occurred" i they were advantageou they would have*helped the pecie to adapt to the condition" *thee allele/gene would have

$een paed onto the oCpring& Thi would have caued *a change in the gene

pool e&g& increaing requency o ,#utation- allele&

Suggest how the allele freBuency for a plant eating &utation could

change as a forest de*elops. (8)

*There will $e a change in requency o

either allele e&g& #utant increae/nor#al decreae *due to the reproductive

ucce o the #utant/non1photoynthetic individual& *' the tree develop the

pond will $e #ore haded thi *,le light #ean- #ean le photoynthei

poi$le& *The photoynthetic individual die/nonphotoynthetic individual

urvive and *pa on the #utation/allele or uing organic co#pound" *thu

allowing #ore organic nutrient in pond&

"S related ea& Buestions''

%lants

Plant bres that &ay be present in eaten &aterial are: clerenchy#a

8$re" %yle# veel and celluloe 8$re&

hat plant tissue that would be the &ain source of the lignin in a

plant? Sclerenchy#a/%yle#&

J

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hat &aterial would be synthesised to for& the cell wall of seedlings?

2elluloe

hat tissue would for& the *essels in a root following dierentiation?

Kyle#

hydrogen and glycoidic $ond are what would need to be bro4en to digest

cellulose.

#escribe the che&ical nature of cellulose. (,)

2elluloe i a *polyaccharide with an *un$ranched/ traight chain&

The celluloe i #ade up o *3 glucoe ?oined $y *1@ glycoidic $ond $etween

the glucoe #olecule& 3etween each chain there are *inter#olecular hydrogen

$ond to hold the tructure together&

Suggest two ad*antages of growing crops of wheat in glasshouses with

articial lighting rather than growing the& in open elds. (2) 3ecaue *crop can $e grown out o

eaon/all year round; *plant photoyntheie @ hour a day; *the crop will

receive le phyical da#age ro# weather/ani#al *a pet control i eaier&

*Lou can alo control other actor uch a 2O" te#perature" hu#idity and

water upply

Cell division

hat is the correct seBuence of stages in &itosis? (rophae" Fetaphae"

'naphae" Telophae

Transcription ta4es place in the GGGGnucleu

&'A and stu!

Triplet of bases that could not be found in &/!" isGGGGG&'denine

Thy#ine 7uanine ,etc-

The seBuence of triplets on a section of #!" used to for& a strand of

pre&/!" is aGG& citron

-plain why a &olecule of #!" can be described as a doublestrandedpolynucleotide. (,) *4t i dou$le1tranded $ecaue it i #ade o two

trand *?oined together $y hydrogen $ond $etween ,the nucleotide!- $ae& *4t

i a polynucleotide a it i #ade o #any nucleotide * lin+ed together $y

phophodieter $ond&

#escribe how the seBuence of bases in a #!" &olecule would be used

to for& the pri&ary structure of a protein. (5)

#escription #!" only &/!" only 0oth #!" and

&/!"

(oly#er or#edro# a ingle

⃝

M

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trand o

nucleotide(entoe preent in

the

nucleotide

⃝

'denine" cytoine"guanine and

thy#ine preent

⃝

6ucleotide lin+ed

$y

phophodieter

$ond

⃝

*' equence o $ae that or# the genetic code deter#ine the a#ino acid

equence" *one triplet o $ae code or an a#ino acid& *The 6' act a a

te#plate when *trancription occur ,i&e& 6' un.ip" #R6' yntheied-; *the

#R6' yntheied then #ove ro# the nucleu to the cytopla#" where*tranlation occur ,e%pand with ri$oo#e" codon1anticodon interaction-& *tR6'

will carry an a#ino acid and *peptide $ond or# $etween the a#ino acid on

diCerent tR6' #olecule; thi 4 i the *equence/ order o a#ino acid i the

pri#ary tructure o a protein&

Cow does &/!" for& during transcription in the nucleus? (,)

irt the *6' trand un.ip" *one ide o the 6' trand

i the te#plate trand that i ued to ro# a #R6' trand *ro# ree nucleotide&

The nucleotide ?oin $y *co#ple#entary $ae pairing" *?oined together $y

hydrogen $ond& *R6'1 poly#erae/ 6' Belicae are the en.y#e involved in

thee reaction&

#escribe how free nucleotides are bonded together in the correct

seBuence in pre&/!". (,) *The equence o $ae / nucleotide on 6'

deter#ine equence on ,pre1-#R6' a the nucleotide can only with their

*co#ple#entary $ae pair e&g& '0 / 27 / 72 / T'& *The $ond $etween the

nucleotide or# in condenation reaction and produce *phophodieter $ond&

*R6'1(oly#erae i the en.y#e that catalye thi reaction&

-plain the function of the codons at each end of a strand of &/!"

during the process of translation. (2) *The codon are either Start/ Stop codon;

*tart codon are needed to $egin polypeptide ynthei and the Stop /6onene

codon i needed to end polypeptide ynthei&

Suggest why the nal triplet of nucleotides on the strand of &/!"

in*ol*ed in the synthesis of this seBuence of a&ino acids did not

correspond with any anticodon on t/!". (2) ' it i the *top

codon that i *ued to end the equencing/ urther attach#ent o tR6';

*ignalling the releae o the polypeptide/ ri$oo#e&

Suggest why a *ariety of dierent protein structures could be for&edfro& the polypeptides synthesised using the &/!" &olecules fro& a

D

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single gene. (,) iCerent protein tructure could $e

or#ed a there are *variation o e%on/ #R6'; thi #ean that each #R6'

trand will have a *diCerent pri#ary tructure due to a diCerent equence o

a#ino acid& *The econdary and tertiary tructure o protein will depend on the

pri#ary tructure/ equence *due to diCerent $ond *uch a Bydrogen/ 4onic/

iulphide $ond& Aach protein will $e developed into *diCerent

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$reed in their natural environ#ent and *larger nu#$er availa$le will reult in a

wider gene pool& *There are pro$le# aociated with releaing ani#al $ac+

into the wild and thee are avoided with reerve ,4&e& ha$ituation-& *ieae i

le li+ely to wipe out the whole population& *reerve allow natural interpeci8c

relationhip/co##unitie to e%it and *natural a#ily/ocial

tructure/$ehaviour"* i&e& $ecaue their natural diet/ood i availa$le&

DethodologyEsing a line of Buadrats to in*estigate the distribution of organis&s isG

a tranect

Fuadrats &ay be di*ided up into s&aller sections to... #a+e it eaier to

eti#ate/#eaure /count the organi# P o the reult are #ore precie

-plain the &eaning of G"ll other abiotic factors were controlled.H(2)

*'$iotic actor are non1living/non1$iological/do not involve

organi#&* 4 all other actor are controlled they are +ept contant/the a#e&

-plain how a Buadrat would be used to obtain the &ean density of the

two species in dierent areas. (,)

*Lou will need to ta+e everal/#ore than

uing *rando# quadrat poition" *thee can $e generated $y a rando# nu#$er

generator on your calculator ,or other uita$le #ethod-&

*Lou would then count the nu#$er o individual in each quadrat and then

*calculate the #ean denity o the pecie uing the total nu#$er o each

pecie divided $y the total area a#pled ,*you need to +now the area o thequadrat to do thi-&

Suggest how results could be displayed in order to co&pare the eect

of temperature on the growth of seedlings of two species. (,)

Lou could ue a *graph uch a a *line

graph with the *KPL a%e correctly drawn ,i&e& te#p at $otto#/L and growth

rate/ti#e at K-& *Lou would ue the a#e cale or the a%e o $oth plant and

would *plot each te#perature/ pecie o plant eparately&

Suggest why seeds may be germinated at 18 °C before being placed in

the experimental conditions. (2) *Thi wa done to control varia$le& *JE2 #ay $e

the opti#u#/ uita$le te#perature or ger#ination& * Thi technique #a+e ure

that all the eed are via$le OR can ger#inate *and o increaing the validity o

the invetigation&

Suggest why ta4ing photographs is a suitable &ethod to count

in*ertebrates. (2) *' they #ove a$out a lot *they are diQcult to

count *o#e #ight $e counted #ore than once/#ied out&

hy would it be diIcult to deter&ine which abiotic factor is in

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*only one actor can $e varied" *other actor need to $e +ept contant& *There

will $e #any $iotic actor in a ha$itat and thee are diQcult to control& *4t will $e

diQcult to et tet actor value a a reult&

Suggest how the scientists can ha*e their results accepted by other

scientists. (2) *Wor+ need to appear in a ,Scienti8c- ?ournal or$eing preented at a conerence&*(eer review o wor+ $y other cientit to

*conider the tudy! validity or relia$ility&

The te&peratures used in this in*estigation were 63 763 263 ,63863 and 563.Suggest what the results of the in*estigation show about the &ini&u&te&perature reBuired for photosynthesis in Elodea. i*e a reason foryour answer . (2)*The #ini#u# te#perature i $etween Do2 and Do2 /a$ove Do2 $ut le thanDo2" *no photoynthei occur at Do2 a *water ree.e at Do2&*We +now that the #ini#u# te#perature i o#ewhere $etween D o2 and D o2$ut there are no #eaure#ent $etween thee te#perature&

-n1y&es control the rate of photosynthesis inElodea. #iscuss how far the results of thisin*estigation support her conclusion. (8)Ber concluion i upported to o#e e%tent a *the hapeo graph i typical o an en.y#e1te#perature graph" i&e&*the rate increae ,up to

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& group ' ID and group 3 ==/==&@ & unit correct 9d#< day1 /d#< per day;

Suggest two reasons why a suspension of cells of a unicellular alga in asolution is &ore suitable for in*estigating 3$2 production inphotosynthesis than using lea*es. (2)3ecaue *a#ple o cell can $e ta+en eaily and there will $e *no da#age toplant/lea /other cell during a#pling; *The car$on dio%ide level ,in water- can$e ad?uted/#aintained/changed eaily; *' alga i ingle celled Ru3(/7(/product cannot pa into other cell/ret o plant" the alga will alo on have *one+ind o cell and that! the one that photoyntheie; Lou can *control the#a/nu#$er/urace area o cell to enure that in!t another infuencing actor;*genetically1i#ilar cell will alo $e ued which will reduce variation and oother actor&

Suggest why it would be ad*isable to illuminate the cells at a high light

intensity during a photosynthesis and C"# experiment. (,)

*' light i needed or the light1dependent

reaction +eeping it at a high intenity #ean *it will not $e a li#iting actor&*Thu 2D concentration i the only li#iting actor& *'T(/ r6'( are produced

during the light dependent reaction" *'T(/ r6'(/ light1dependent product are

required or the light1independent reaction/ 2alvin cycle/ car$on18%ation&

3oth *Ru3( and 7( level re#ain contant until the car$on dio%ide i lowered;*thee are ued in the 2alvin cycle& *'t lower car$on dio%ide level the Ru3(increae and drop and then tay contant" it *rie at 5Decond $ecaue iti $eing regenerated and it all at

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dio%ide into 7(& *The Ru3( level re#ain contant once a ,new- equili$riu# ireached&;'t lower car$on dio%ide level the 7( drop and then tay contant" *it drop at5D econd $ecaue le car$on dio%ide i availa$le to convert into 7(/lecar$on 8%ation occur& *4t level out at a lower level a car$on dio%ide i tillavaila$le $ut at lower level& *credit #anipulation o 8gure ,i&e& 7(drop $y au-

3o&pare the changes in &ean en*iron&ental te&peraturebetween the pre&onsoon and the post&onsoon periodsfro& 7 to 2. (,)*There i no/little change in pre1#onoon te#perature $ut pot1#onoon ha rien overall" although they *$oth fuctuate the*fuctuation #atch each other; the fuctuation are within/lethan o2& *The range o ,#ean- te#perature i greater OR howgreater fuctuation" in pot1#onoon period& *Reerence to aparticular change in $oth e&g& $oth decreaed $etween JDD to

J5D& *2redit correct #anipulation o 8gure to co#pare withunit&3alculate the o*erall percentage increase in the &ean !PP fro& =anuaryto Day. (,)*2orrect reading ro# graph indicated e&g& , and-*2orrect u$traction e&g& ,1 / D-*2orrect diviion ,$y - % DD/ to give DDD

Esing infor&ation fro& the graphs describeand eplain the relati*e eects of te&perature and hours of sunlight on!PP in this grassland. (8)*3etween Hanuary and 'pril 6(( increae a light increae" there i a*correlation $etween 6(( and light; thu an *increae in light increae the rateo photoynthei/'T( and o the energy availa$le or 2alvin 2ycle" thi i$ecaue *,credit correct detail o photoynthei- e&g& light reult in e%citationo electron& *The change in 6(( occur ater the change in light/pea+ light i'pril and pea+ 6(( i in Fay&3ut there i *no real correlation $etween te#perature and 6((/reerence tote#perature fuctuating depite *te#perature aCecting how quic+ly en.y#e

wor+" or e%a#ple *6(( all ro# Fay $ut the te#perature re#ain high& *)ightand te#perature are li#iting actor&

Ese the data in the tables to suggest which of the two species is betteradapted for growth at a wide range of latitudes (distance fro& theeBuator). i*e reasons for your choice.(8)

5

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*Sea plantain/%lantago maritima are $etter adapted& 3ecaue*diCerent latitude have diCerent #ean te#perature and the *eaplantain grow $etter in all three

Te#perature& Wherea *$og edge/obresia simpliciuscula doe notgrow very well at lower te#perature/Do2 and @o2& *2reditappropriate co#parative #anipulated 8gure i&e& Sea (lantain haI

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Suggest why the students were not able to draw*alid conclusions about the eect of saturationof the soil by water on the distribution of the*e plant species. (,)*3ecaue aturation wa not #eaured/depth o waterdoe not give aturation data" there are *no data onother actor/varia$le that *#ay $e aCecting

ditri$ution/notcontrolled/conounding *i&e&Te#perature& *Only one eto data i ta+en&

3alculate the percentage of the &ean PP that re&ains as !PP withinplants on -arth.

The #ean 7(( or plant on Aarth i @&@ D= H #N yearN& The plant ue

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Suggest why it was i&portant that this in*estigation was carried out ata high light intensity. (,)*So that each te#perature ha the a#e light intenity which *#ut $e a$ovethe threhold/co#penation point *$elow which no net photoynthei ta+eplace& Thi enure that *light i not li#iting actor/o te#perature i the onlyli#iting actor&*(hotoynthei produce #aterial needed or growth&

Suggest two abiotic factors other than light intensity that would needto be controlled in this (te&perature) in*estigation.*Wavelength/colour/requency o light; *2O concentration; *pB o olution;#ineral concentration

J

unit 4 topic 5

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