How was Biology Paper 42

[Jinkglex]

you just had to write photolysis, but non-cyclic is correct too. And it was P680 [Photosystem II]

 

[Amaryllis]

you just had to write photolysis, but non-cyclic is correct too. And it was P680 [Photosystem II]

i wrote both photolysis -non-cyclic,...
so how to prepare for paper 5 ?, i know nothing about this paper

 

[rogue94]

That natural selection question (fish, pools) was repeated. See the mark scheme of O/N/04 Q5. It is an almost identical question.

http://papers.xtremepapers.com/CIE/...and AS Level/Biology (9700)/9700_w04_ms_4.pdf

 

[stella jazz]

i found that neurone question crazy

 

[tasmiah2310]

same here what did u write for the question (which light dependent stage oxygen is produced) i wrote non cyclic - photolysis and the photosystem was type 2 right ?? and the question under it , i wrote because some oxygen is used in respiration

I just wrote photolysis , then photosystem 2.

and question under it, you mean the one which asked why it doesnt give a true value for photosynthesis?
I wrote because concentration of CO2 is limiting factor

 

[tasmiah2310]

That natural selection question (fish, pools) was repeated. See the mark scheme of O/N/04 Q5. It is an almost identical question.

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w04_ms_4.pdf

-______________________-

why didnt i see this before.

 

[stella jazz]

That natural selection question (fish, pools) was repeated. See the mark scheme of O/N/04 Q5. It is an almost identical question.

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w04_ms_4.pdf

omg its exactly the same.....y didn't i do this ppr y??y??

 

[lionkill3r]

and question under it, you mean the one which asked why it doesnt give a true value for photosynthesis?
I wrote because concentration of CO2 is limiting factor

I wrote some of the O2 is suefd within the plant itself for respiration so not all o2 produced is realeased from the plant

 

[littlecloud11]

I wrote some of the O2 is suefd within the plant itself for respiration so not all o2 produced is realeased from the plant

Yup, wrote the same. =D

 

[Alice123]

Yup, wrote the same. =D

What was yr %??? i got 10.4... so many people got so many different answers :S

 

[littlecloud11]

What was yr %??? i got 10.4... so many people got so many different answers :S

It was 10.4%
More than sure about this one.

 

[haroon740]

my paper was okay but i left a question it worth 2 mark , and now i feel guilty i should have written anything in it did u leave any questions ?
guys, do u know how are the grades for Alevels calculated , if its taken in two m/j sessions ? i mean i already took biology AS last year and got an A ,and this year i took A2 , and i need to get an A or A* ,, my teacher told its hard to get it if taken in 2 sessions ..please can anyone answer

CAmmmmon
it aint tht hard honestly,if u;re scoring above 66
you;re safe and got A in AS then gettin A wont be prob inshAllah

 

[Amaryllis]

CAmmmmon
it aint tht hard honestly,if u;re scoring above 66
you;re safe and got A in AS then gettin A wont be prob inshAllah

inshallah ! thank you so much for these encouraging words ..
am nervous because we actually dont know how the examiners correct our answers in A levels ,they need too much details , and i still didnt practice paper 5 yet

 

[rogue94]

For Question 10: (Section B)

(a) structure of a chloroplast (7)
- biconvex disc
- 3-10 um diameter
- double, membrane/envelope
- internal membrane system
- flattened or fluid-filled sacs/thylakoids
- arranged in stacks/grana
- hold pigments/named pigment
- clusters of pigments
- (membrane of grana) hold ATP synthase
- intergranal lamellae
- stroma/ground substance
- lipids/strarch grains
- contains enzymes of Calvin Cycle/rubisco
- stroma contains ribosomes/DNA
any other valid point such as presence of mRNA, tRNA, proteins, 70S ribosomes, brief detail of photosystems, electron carriers.
You had to mention any seven of the above points, but had to include references to shape, size and contents (internal membrane system + stroma)

(b) adaptation of rice (8)
- low oxygen (availability) in water (when soil is flooded)
- results in anaerobic respiration
- anaerobic respiration produces alcohol
- rice tolerant to alcohol
- because rice has high levels of alcohol dehydrogenase/enzyme that breaks down alcohol
- presence of aerenchyma/air spaces
- in mesophyll/cortex
- formed by cell death
- provides oxygen
- for aerobic respiration/because conditions are anaerobic
- allows escape of ethene/buoyancy/active transport
- stem elongation
- leaves above the surface of water/in contact with air

The syllabus states: candidates should be able to explain how rice is adapted to grow with roots submerged in water in terms of tolerance to ethanol and presence of aerenchyma. Hence, these two points were to be mentioned along with their relevant detail.

 

[externityxzx]

For Question 10: (Section B)

(a) structure of a chloroplast (7)
- biconvex disc
- 3-10 um diameter
- double, membrane/envelope
- internal membrane system
- flattened or fluid-filled sacs/thylakoids
- arranged in stacks/grana
- hold pigments/named pigment
- clusters of pigments
- (membrane of grana) hold ATP synthase
- intergranal lamellae
- stroma/ground substance
- lipids/strarch grains
- contains enzymes of Calvin Cycle/rubisco
- stroma contains ribosomes/DNA
any other valid point such as presence of mRNA, tRNA, proteins, 70S ribosomes, brief detail of photosystems, electron carriers.
You had to mention any seven of the above points, but had to include references to shape, size and contents (internal membrane system + stroma)

(b) adaptation of rice (8)
- low oxygen (availability) in water (when soil is flooded)
- results in anaerobic respiration
- anaerobic respiration produces alcohol
- rice tolerant to alcohol
- because rice has high levels of alcohol dehydrogenase/enzyme that breaks down alcohol
- presence of aerenchyma/air spaces
- in mesophyll/cortex
- formed by cell death
- provides oxygen
- for aerobic respiration/because conditions are anaerobic
- allows escape of ethene/buoyancy/active transport
- stem elongation
- leaves above the surface of water/in contact with air

The syllabus states: candidates should be able to explain how rice is adapted to grow with roots submerged in water in terms of tolerance to ethanol and presence of aerenchyma. Hence, these two points were to be mentioned along with their relevant detail.

thats the question i did
i found that neurone question confusing.... for (a) i wrote that the resting potential is maintained by the sodium potassium pump.... since that stops, ions will diffuse down their electrochemical gradient into the cell (from -40mV to +0mV ).
is that correct though? i didnt know what else to write...

 

[haroon740]

inshallah ! thank you so much for these encouraging words ..
am nervous because we actually dont know how the examiners correct our answers in A levels ,they need too much details , and i still didnt practice paper 5 yet

Everything is pre-written ,but with prayers it can be re-written

 

[raamish]

my paper was okay but i left a question it worth 2 mark , and now i feel guilty i should have written anything in it did u leave any questions ?
guys, do u know how are the grades for Alevels calculated , if its taken in two m/j sessions ? i mean i already took biology AS last year and got an A ,and this year i took A2 , and i need to get an A or A* ,, my teacher told its hard to get it if taken in 2 sessions ..please can anyone answer

i left questions that were like 6-8 marks. And the paper was easy but it was too long. I didnt have time to write all the answers And in my hurry i made mistakes too about 5-6 marks. Im hoping the gt will be 7oish so that i can get an A inshallah

 

[MahaS]

For Question 10: (Section B)

(a) structure of a chloroplast (7)
- biconvex disc
- 3-10 um diameter
- double, membrane/envelope
- internal membrane system
- flattened or fluid-filled sacs/thylakoids
- arranged in stacks/grana
- hold pigments/named pigment
- clusters of pigments
- (membrane of grana) hold ATP synthase
- intergranal lamellae
- stroma/ground substance
- lipids/strarch grains
- contains enzymes of Calvin Cycle/rubisco
- stroma contains ribosomes/DNA
any other valid point such as presence of mRNA, tRNA, proteins, 70S ribosomes, brief detail of photosystems, electron carriers.
You had to mention any seven of the above points, but had to include references to shape, size and contents (internal membrane system + stroma)

(b) adaptation of rice (8)
- low oxygen (availability) in water (when soil is flooded)
- results in anaerobic respiration
- anaerobic respiration produces alcohol
- rice tolerant to alcohol
- because rice has high levels of alcohol dehydrogenase/enzyme that breaks down alcohol
- presence of aerenchyma/air spaces
- in mesophyll/cortex
- formed by cell death
- provides oxygen
- for aerobic respiration/because conditions are anaerobic
- allows escape of ethene/buoyancy/active transport
- stem elongation
- leaves above the surface of water/in contact with air

The syllabus states: candidates should be able to explain how rice is adapted to grow with roots submerged in water in terms of tolerance to ethanol and presence of aerenchyma. Hence, these two points were to be mentioned along with their relevant detail.

Well i messed this up *facepalm*

 

[MahaS]

I spent so much time learning about monoclonal antibodies and dipsticks and stuff and they didnt come -_-

 

[uberleet]

For Question 10: (Section B)

(a) structure of a chloroplast (7)
- biconvex disc
- 3-10 um diameter
- double, membrane/envelope
- internal membrane system
- flattened or fluid-filled sacs/thylakoids
- arranged in stacks/grana
- hold pigments/named pigment
- clusters of pigments
- (membrane of grana) hold ATP synthase
- intergranal lamellae
- stroma/ground substance
- lipids/strarch grains
- contains enzymes of Calvin Cycle/rubisco
- stroma contains ribosomes/DNA
any other valid point such as presence of mRNA, tRNA, proteins, 70S ribosomes, brief detail of photosystems, electron carriers.
You had to mention any seven of the above points, but had to include references to shape, size and contents (internal membrane system + stroma)

(b) adaptation of rice (8)
- low oxygen (availability) in water (when soil is flooded)
- results in anaerobic respiration
- anaerobic respiration produces alcohol
- rice tolerant to alcohol
- because rice has high levels of alcohol dehydrogenase/enzyme that breaks down alcohol
- presence of aerenchyma/air spaces
- in mesophyll/cortex
- formed by cell death
- provides oxygen
- for aerobic respiration/because conditions are anaerobic
- allows escape of ethene/buoyancy/active transport
- stem elongation
- leaves above the surface of water/in contact with air

The syllabus states: candidates should be able to explain how rice is adapted to grow with roots submerged in water in terms of tolerance to ethanol and presence of aerenchyma. Hence, these two points were to be mentioned along with their relevant detail.

ab thori tension horahi hai k itna fit bhi nhee hua paper xD