[The Assassin]

(Original post by iAre Teh Lejend)
You my friend, know EXACTLY what you're saying.

Thanks lol.

[totw]

For the polymer question i just said its a polymer because it is made up of lots of monomers. Would this get a mark???

Also for the two differences between starch and cellulose, for cellulose i said it had hydrogen bonds, and starch didnt. Would i get a mark for this as well???

Also for the index of diversity question does the wheat field have a greater or lower index of diversity?????

Really appreciate it if someone could answer

Thanks

[DomJay24]

(Original post by clairelouise444)
Ah I wrote hydroxyl group

DAMN it I thought I would try and be clever and put 'carboxyl' group

[navy]

I've never seen 60-65 for an A. I'm pretty sure itl be 57. What makes everyone think 60 will be an A?

[RosieH7]

(Original post by totw)
For the polymer question i just said its a polymer because it is made up of lots of monomers. Would this get a mark???

Also for the two differences between starch and cellulose, for cellulose i said it had hydrogen bonds, and starch didnt. Would i get a mark for this as well???

Also for the index of diversity question does the wheat field have a greater or lower index of diversity?????

Really appreciate it if someone could answer

Thanks

I put that about monomers, probably pushing it for a mark, maybe we will get nice examiners?

Lower for the wheat because there was only 3 species present instead of 5 and very small numbers of 2 species while the other species was very predominant?

ps for the starch thing i think you would as it refered to structure didn't it and you are correct in saying that, so it would be a bit harsh?

[totw]

(Original post by RosieH7)
I put that about monomers, probably pushing it for a mark, maybe we will get nice examiners?

Lower for the wheat because there was only 3 species present instead of 5 and very small numbers of 2 species while the other species was very predominant?

ps for the starch thing i think you would as it refered to structure didn't it and you are correct in saying that, so it would be a bit harsh?

haha hopefully

Thanks for the help

[pjanoo]

here's hoping I get a generous examiner

[Samthing]

Would 1.29 for the diversity index be okay? I can only see 1.285 and 1.3 on here!

I came out thinking I completely messed it up, this thread has kind of calmed me down. So happy with the tissue fluid question!

[iAre Teh Lejend]

(Original post by The Assassin)
Didn't mind this paper, although it seems there were many ambiguous questions.

; denotes a mark point. There are obviously more answers and I've missed out many questions - so please help!

Thanks to TheBigDog and some other people for some help

1)

a) Diffusion. (1 mark)

b) Thin so short diffusion pathway; large surface area (2 marks)

c) A collection of tissues joined to serve a common/specific function. (1 mark)

d) Diffusion; through stomata; diffusion gradient set up(3 marks)

2)

a) The sugar beet had: (4 marks)

Larger leaves; more surface area for photosynthesis

Larger root; allows more sugar storage/more water storage for photosynthesis.

b) How does the farmer profit? (more answers) (1 mark)

More rapid growth in a shorter time;
saves on fertilisers;

c) How would growing the sugar beet affect the diversity of the sugar roots?
(2 marks)

Grown on large scale;
using the same specific allele;
for more yield of sugar (in shorter time);
(so) diversity reduced;

3) a) Monomers of cellulose (1 mark)

Beta glucose

b) What bond is shown? (1 mark)

Glycosidic

c) What group is Z?

OH/Hydroxyl

d) 2 reasons - Differences between cellulose and starch (2 or 4 marks?)

Starch is made up of alpha glucose; but cellulose beta
starch forms purple complex with iodine; cellulose doesn't form colour;
storage role for starch; structural role for cellulose;
starch has flexible chains; cellulose had straight chains;
starch forms helix; cellulose forms microfibrils

e) Describe structure of cellulose related to function
(2 marks)

long straight chains;
can form microfibrils;
provide rigidity to cell walls;
so they resist osmotic pressure;
held together by hydrogen bonds;
difficult to break bonds;
resists digestion / enzyme activity


4)

a) How do you know this is a polymer? (1 mark)

Joined by many nucleotides / has sugar phosphate backbone / units are repeating

b) Name the molecules.
(Don't remember the order) (3 marks)

Hydrogen bonds
Deoxyribose/Pentose Sugar (the pentagon)
Phosphate (circle)

c) Adenine; Guanine & Cytosine; 16 and 16 each (I think?) (2 marks)

d) Minimum number required

51*3 = 153

e) Introns / junk DNA.

5) a) Why is mitosis essential?


Growth;
Quick cell restoration/repair/regeneration;
asexual reproduction;

b) Stage the two stages in A and B
Ambiguous - I believe they'll be generous.

A -

Prophase; because the chromosomes were condensed and visible

OR

Metaphase; chromsomes were lining up in the equator

B-

Anaphase; chromosomes move to the opposite ends of the cell.

b) 2 hours. Interphase was 90%. 100-90 = 10%. 10% of 20 hours is 2.



6) Index of diversity questions

a) Kingdom / Phylum / Class (1 mark)

b) Family

c) 1.285-1.3

d) Would the index of diversity for the wheat field be less or more? (2 marks)

less;
every species apart from oak aphids had a lower number or organisms than the organisms found in the wood;
many species have 0 organisms;

e) How would shrubs help? (2 marks)

Increase diversity;
more habitats;
more food sources;

7) a) Explain the changes in the graph (3 marks)

(Xylem pressure low during the night) as stomata closed and there’s less transpiration;
(During day it increases) because rate of water movement increases;
because of more sunlight;
This puts the water column under pressure so the xylem is drawn in so diameter is reduced

b) Why are the pressure values negative? (1 mark)

Transpiration pull/xylem pulled in by tension

8)

a) Explain why the artery has the thickest wall? (1 mark)

Artery has thicker walls because pressure is higher.

b) Why is the thickness of the aorta different every time?
(3 marks)

Different surges in pressure;
streches;
recoils;

c) Which showed the greatest variation in wall thickness? (2 marks) Bitch of a question - ambiguous.

Aorta; greatest (difference in) standard deviation

Pulmonary veins beacuse the standard deviation for that was highest relative to what the actual mean value was.

d) Explain the formation of tissue fluid (6 marks)

At (arteriole) end of capillary;
Hydrostatic / blood pressure;
Forces out soluble / small molecules;
And water;
Protein remains in blood / plasma;
Molecules too large;
More negative / lower water potential at (venule) end;
Water drawn in by osmosis / diffuses in;
lymphatic system collects excess tissue fluid;
Some fluid/lymph returned to blood by lymphatic system;


9) a) i) Why were the bacteria incubated at 35 degrees? (1 mark)
Similar temperature to body; optimum temperature for bacterial growth.

a) ii) Why was the same amount of bacteria used?
(1 mark)

So you can compare / there'd be more bacteria at the end for different concentrations / decreases validity / results affected

b) i) Why was a control used? (1 mark)

To show that it was only the antibiotic that affected the results

ii) Describe the changes shown on the graph (2 marks)

Rapid decrease up to 5; slight decrease from 5-10; steady but slow decrease from 10-50; extremely slow decrease/levels off from 50-100

iii) The scientists concluded that 50 micrograms was the most efficient concentration. Do you agree?
(3 marks)

Correlation doesn't mean causation;
may be other factor involved;
graph supports this because most amount of bacteria were killed then;
not much difference from above 50 so can save on cost/less risk of resistant bacteria replicating (?);


c) How does bacteria develop resistance? (2 marks)

Random mutation;
Gene transmission

d) Why were the people similar ages

Increases reliablity / more age representitive / affects different ages in different ways

e) The scientists said that taking antibiotics was the right thing to do. Does the information in b c and d support this? (4 marks) Really weird question.

No -

Could wipe out competition and leave resistant strain;
strain divides and gives genes via vertical gene transmission;
there wasn't much difference between the volunteers in 2 months;
both values were the same in 3 months;
antibiotic testing showed that there was still 40% of bacteria despite 100% concentration of antibiotics

Yes -

antibiotics destroy bacteria anyways and can reduce risk of heart disease;



Predicted grade boundaries

70/85 - 140 UMS
60/85 - A
55/85 - B
49/85 - C
44/85 - D

You forgot to talk about the humming bird question :P

[Theteacake]

So guys did you think it was hard? My friends are saying it was, but i found it okay :/

[The Assassin]

(Original post by iAre Teh Lejend)
You forgot to talk about the humming bird question :P

I just added that haha. I'm missing one question - there was the table showing the different coloured feathers and whatnot, and two questions after that it asked about courtship. Was there a question before that?

[iAre Teh Lejend]

(Original post by The Assassin)
I just added that haha. I'm missing one question - there was the table showing the different coloured feathers and whatnot, and two questions after that it asked about courtship. Was there a question before that?

hmmm i dont remmeber, haha.

[drlesliechoi]

Grade boundary predictions?

[amy37]

Hey the cellulose and starch comparison question was definitely 2 marks
I really hope the markscheme is like this because then I've done alright
Thank you!

[N0body]

For 10 a (iii) from my past experience I don't believe "other factors" would give you the mark unless you actually give an example

Other than that why the devil did I write osmosis for the first question -.-

Edit: Once again AQA loves to be completely random as they had to put Q5 in didn't they

[henshin]

Hmm I just have one question I would really love to have answered, for the mitosis time question I just put 2 and forgot to write hours, does that matter? Also I was real stupid on that aorta thickness question I said that the thickness increases during systole to resist the high pressure... It confused me cus I though stretching of fibres doesn't change thickness Doh!

[amy37]

(Original post by The Assassin)
I just added that haha. I'm missing one question - there was the table showing the different coloured feathers and whatnot, and two questions after that it asked about courtship. Was there a question before that?

Yeah I think there was a question at the top of the page with the table..pretty sure it was a 1 marker or something

[iAre Teh Lejend]

(Original post by The Assassin)
Didn't mind this paper, although it seems there were many ambiguous questions.

; denotes a mark point. There are obviously more answers and I've missed out many questions - so please help!

Thanks to TheBigDog and some other people for some help

1)

a) Diffusion. (1 mark)

b) Thin so short diffusion pathway; large surface area (2 marks)

c) A collection of tissues joined to serve a common/specific function. (1 mark)

d) Diffusion; through stomata; diffusion gradient set up(3 marks)

2)

a) The sugar beet had: (4 marks)

Larger leaves; more surface area for photosynthesis

Larger root; allows more sugar storage/more water storage for photosynthesis.

b) How does the farmer profit? (more answers) (1 mark)

More rapid growth in a shorter time;
saves on fertilisers;

c) How would growing the sugar beet affect the diversity of the sugar roots?
(2 marks)

Grown on large scale;
using the same specific allele;
for more yield of sugar (in shorter time);
(so) diversity reduced;

3) a) Monomers of cellulose (1 mark)

Beta glucose

b) What bond is shown? (1 mark)

Glycosidic

c) What group is Z?

OH/Hydroxyl

d) 2 reasons - Differences between cellulose and starch (2 or 4 marks?)

Starch is made up of alpha glucose; but cellulose beta
starch forms purple complex with iodine; cellulose doesn't form colour;
storage role for starch; structural role for cellulose;
starch has flexible chains; cellulose had straight chains;
starch forms helix; cellulose forms microfibrils

e) Describe structure of cellulose related to function
(2 marks)

long straight chains;
can form microfibrils;
provide rigidity to cell walls;
so they resist osmotic pressure;
held together by hydrogen bonds;
difficult to break bonds;
resists digestion / enzyme activity


4)

a) How do you know this is a polymer? (1 mark)

Joined by many nucleotides / has sugar phosphate backbone / units are repeating

b) Name the molecules.
(Don't remember the order) (3 marks)

Hydrogen bonds
Deoxyribose/Pentose Sugar (the pentagon)
Phosphate (circle)

c) Adenine; Guanine & Cytosine; 16 and 16 each (I think?) (2 marks)

d) Minimum number required

51*3 = 153

e) Introns / junk DNA.

5) a) Why is mitosis essential?


Growth;
Quick cell restoration/repair/regeneration;
asexual reproduction;

b) Stage the two stages in A and B
Ambiguous - I believe they'll be generous.

A -

Prophase; because the chromosomes were condensed and visible

OR

Metaphase; chromsomes were lining up in the equator

B-

Anaphase; chromosomes move to the opposite ends of the cell.

b) 2 hours. Interphase was 90%. 100-90 = 10%. 10% of 20 hours is 2.



6) Index of diversity questions

a 1.285-1.3

b) Would the index of diversity for the wheat field be less or more? (2 marks)

less;
every species apart from oak aphids had a lower number or organisms than the organisms found in the wood;
many species have 0 organisms;

c) A journalist mentioned that farming reduces the diversity. (2 marks)

No - farming wasn't mentioned;
yes - farmers clear out woodland/other plants to make room for wheat fields;

d) How would shrubs help? (2 marks)

Increase diversity;
more habitats;
more food sources;

7)

a) Kingdom / Phylum / Class (1 mark)

b) Family

c)

d)

Courtship identifies members of same species;
male species different colour to other male species;
likewise for female;

e) The question of Protein sequence.

Compared same protein;
same species will have similar base sequences
DNA Hybridisation;
more hydrogen bonds form;
more heat required indicates relationship;
amount of precipitate from both species indicates relationship

8) a) Explain the changes in the graph (3 marks)

(Xylem pressure low during the night) as stomata closed and there’s less transpiration;
(During day it increases) because rate of water movement increases;
because of more sunlight;
This puts the water column under pressure so the xylem is drawn in so diameter is reduced

b) Why are the pressure values negative? (1 mark)

Transpiration pull/xylem pulled in by tension

0)

a) Explain why the artery has the thickest wall? (1 mark)

Artery has thicker walls because pressure is higher.

b) Why is the thickness of the aorta different every time?
(3 marks)

Different surges in pressure;
streches;
recoils;

c) Which showed the greatest variation in wall thickness? (2 marks) Bitch of a question - ambiguous.

Aorta; greatest (difference in) standard deviation

Pulmonary veins beacuse the standard deviation for that was highest relative to what the actual mean value was.

d) Explain the formation of tissue fluid (6 marks)

At (arteriole) end of capillary;
Hydrostatic / blood pressure;
Forces out soluble / small molecules;
And water;
Protein remains in blood / plasma;
Molecules too large;
More negative / lower water potential at (venule) end;
Water drawn in by osmosis / diffuses in;
lymphatic system collects excess tissue fluid;
Some fluid/lymph returned to blood by lymphatic system;


10) a) i) Why were the bacteria incubated at 35 degrees? (1 mark)
Similar temperature to body; optimum temperature for bacterial growth.

a) ii) Why was the same amount of bacteria used?
(1 mark)

So you can compare / there'd be more bacteria at the end for different concentrations / decreases validity / results affected

b) i) Why was a control used? (1 mark)

To show that it was only the antibiotic that affected the results

ii) Describe the changes shown on the graph (2 marks)

Rapid decrease up to 5; slight decrease from 5-10; steady but slow decrease from 10-50; extremely slow decrease/levels off from 50-100

iii) The scientists concluded that 50 micrograms was the most efficient concentration. Do you agree?
(3 marks)

Correlation doesn't mean causation;
may be other factor involved;
graph supports this because most amount of bacteria were killed then;
not much difference from above 50 so can save on cost/less risk of resistant bacteria replicating (?);


c) How does bacteria develop resistance? (2 marks)

Random mutation;
Gene transmission

d) Why were the people similar ages

Increases reliablity / more age representitive / affects different ages in different ways

e) The scientists said that taking antibiotics was the right thing to do. Does the information in b c and d support this? (4 marks) Really weird question.

No -

Could wipe out competition and leave resistant strain;
strain divides and gives genes via vertical gene transmission;
there wasn't much difference between the volunteers in 2 months;
both values were the same in 3 months;
antibiotic testing showed that there was still 40% of bacteria despite 100% concentration of antibiotics

Yes -

antibiotics destroy bacteria anyways and can reduce risk of heart disease;



Predicted grade boundaries

70/85 - 140 UMS
60/85 - A
55/85 - B
49/85 - C
44/85 - D

there was a 2 marker about the signifnce of standard deviation

[kraftzz]

(Original post by amy37)
Yeah I think there was a question at the top of the page with the table..pretty sure it was a 1 marker or something

think it was somthing to do with standard deviation

[The Assassin]

(Original post by iAre Teh Lejend)
there was a 2 marker about the signifnce of standard deviation

Ah yes that was it! Thanks. Was the answer to that to show variation/variety, and to see, if they overlapped, if it was due to chance? (I remember something like that from an old mark scheme)