AQA A-level Biology 7402 - Paper 2 - 13th June 2019

Original post by GCSEStudent903

PAPER 2 PREDICTIONS:

BOLD/UNDERLINE = 95% SURE
BOLD = VERY LIKELY
* COULD BE USED SOMEHOW IN THE PASSAGE (AT THE END OF PAPER)

• Aerobic Respiration / The Electron Transport Chain *
• Tropisms / IAA
• Animal Movement – Taxis and Kinesis
• Pacinian Corpuscle
• Phosphorous Cycle
• Action Potentials and The Nerve Impulse*
• Muscle Structure
• Muscle Contraction
• Glucose Control / Diabetes
• Second Messenger Model
• Kidney Structure / Production of Urine *
• Inheritance – codominance, sex-linkage.
• Cell Specialisation / Totipotency
• In Vivo Amplification of DNA / ligation / marker genes / replica plating
• In Vitro / PCR
• Acetylation and Methylation of DNA
• DNA Fingerprinting and VNTRs*
• DNA Probes
• Genetic Screening

What exactly is there to revise for DNA fingerprinting/VNTRs? Really can’t think of what to learn as it will all just be applied?

Also I think photosynthesis is bound to come up as it’s such a big topic...

Lastly are there any specific practicals you would recommend knowing about? Thanks for the one you posted earlier cos I’d never even seen it before.

(edited 4 years ago)

Reply 43

In my textbook it says you won’t need to calculate it but will need to be able to use it to figure out whether to reject null etc.

Original post by georgehsclark

Do we have to know how to do the Chi-Squared test?
in spec it says:
"Use of the Chi-squared test to compare the goodness of fit observed phenotypic rations with expected ratios."

Reply 44

bayanotbee

9

what about ecology & ecosystems and stuff?

Original post by GCSEStudent903

PAPER 2 PREDICTIONS:

BOLD/UNDERLINE = 95% SURE
BOLD = VERY LIKELY
* COULD BE USED SOMEHOW IN THE PASSAGE (AT THE END OF PAPER)

• Aerobic Respiration / The Electron Transport Chain *
• Tropisms / IAA
• Animal Movement – Taxis and Kinesis
• Pacinian Corpuscle
• Phosphorous Cycle
• Action Potentials and The Nerve Impulse*
• Muscle Structure
• Muscle Contraction
• Glucose Control / Diabetes
• Second Messenger Model
• Kidney Structure / Production of Urine *
• Inheritance – codominance, sex-linkage.
• Cell Specialisation / Totipotency
• In Vivo Amplification of DNA / ligation / marker genes / replica plating
• In Vitro / PCR
• Acetylation and Methylation of DNA
• DNA Fingerprinting and VNTRs *
• DNA Probes
• Genetic Screening

Reply 45

bayanotbee

9

ngl im ******** myself for this paper, i still have to revise section 7 and 8 and section 7 is so looooooong i dont think i'll manage it all by thursday

Reply 46

Alayna1234

18

Original post by VictiniCup

Question regarding mark scheme: currently doing the 2018 paper 2. For one of the questions I have written down autosomal linkage but the mark scheme says genes are linked and the phrase is not underlined. Would I get a mark for saying autosomal linkage?

No, you have to explain that the genes are linked, hence why there are more offspring with said set of genes

Reply 47

GCSEStudent903

Original post by Azeee

What exactly is there to revise for DNA fingerprinting/VNTRs? Really can’t think of what to learn as it will all just be applied?

Also I think photosynthesis is bound to come up as it’s such a big topic...

Lastly are there any specific practicals you would recommend knowing about? Thanks for the one you posted earlier cos I’d never even seen it before.

For DNA fingerprinting I would revise the method used to produce the fingerprint (i.e. use of restriction endonucleases, probes, nylon membrane etc etc) and know what VNTRs are, where they're found (introns) and what we can use them for (comparisons between organisms - show different species etc etc).

And, as you said, the rest would be application.

Photosynthesis came up in 2017 (as the DCPIP practical) and 2018 (light independent reaction), so, I think respiration is more likely to come up as that hasn't been asked directly (apart from in 2018 as the practical involving yeast which was anaerobic respiration). More specifically, they haven't asked the electron transport chain so this could be asked in the context of photosynthesis or respiration.

As for specific practicals, who knows. Learn them all. They're more likely to get you to apply the practicals in different contexts. I think the chromatography practical has a good chance of coming up.

Reply 48

GCSEStudent903

Original post by Alayna1234

No, you have to explain that the genes are linked, hence why there are more offspring with said set of genes

Yeah, you need to specify the genes are linked (and thus autosomal linkage). A similar question was asked in 2018 where genes were mentioned in the mark scheme (not just autosomal linkage).

Reply 49

LordSciencelol

3

Original post by Rahulsharma21

How accurate are these predictions?

They are 78.463% accurate ahaha

Original post by Virolite

lmao at people who ask for predictions then ask how accurate they are

Reply 50

LordSciencelol

3

Original post by bayanotbee

ngl im ******** myself for this paper, i still have to revise section 7 and 8 and section 7 is so looooooong i dont think i'll manage it all by thursday

try revising 5-8 in a day because you had to tryhard on chemistry that you did bad on rip

Reply 51

1357anonymous

11

You won’t need to remember the formula of it, more like they’ll give you a table to calculate observed and expected then they’ll just ask u to insert into the formula they gave you, or using chi-squared and critical values to determine whether or not null hypothesis is rejected :smile:

Original post by georgehsclark

Do we have to know how to do the Chi-Squared test?
in spec it says:
"Use of the Chi-squared test to compare the goodness of fit observed phenotypic rations with expected ratios."

Reply 52

GoldenShade

Original post by GCSEStudent903

PAPER 2 PREDICTIONS:

BOLD/UNDERLINE = 95% SURE
BOLD = VERY LIKELY
* COULD BE USED SOMEHOW IN THE PASSAGE (AT THE END OF PAPER)

• Aerobic Respiration / The Electron Transport Chain *
• Tropisms / IAA
• Animal Movement – Taxis and Kinesis
• Pacinian Corpuscle
• Phosphorous Cycle
• Action Potentials and The Nerve Impulse*
• Muscle Structure
• Muscle Contraction
• Glucose Control / Diabetes
• Second Messenger Model
• Kidney Structure / Production of Urine *
• Inheritance – codominance, sex-linkage.
• Cell Specialisation / Totipotency
• In Vivo Amplification of DNA / ligation / marker genes / replica plating
• In Vitro / PCR
• Acetylation and Methylation of DNA
• DNA Fingerprinting and VNTRs *
• DNA Probes
• Genetic Screening

wow this is amazing! Also what is replica plating?

Reply 53

GoldenShade

Never mind, just seen your past explanation :smile:

Original post by GoldenShade

wow this is amazing! Also what is replica plating?

Reply 54

Thanks - I never actually did the practical component of a level biology (don’t need it for my offer) so I don’t know exactly all of the 15 different experiments or whatever - do you have any resources that have them all in a list by any chance?

Also do you know the reasons for why we would pick a particular graph (i.e scatter graph vs curve vs line, cos there’s a question on the spec paper like that question 9.2)

Original post by GCSEStudent903

For DNA fingerprinting I would revise the method used to produce the fingerprint (i.e. use of restriction endonucleases, probes, nylon membrane etc etc) and know what VNTRs are, where they're found (introns) and what we can use them for (comparisons between organisms - show different species etc etc).

And, as you said, the rest would be application.

Photosynthesis came up in 2017 (as the DCPIP practical) and 2018 (light independent reaction), so, I think respiration is more likely to come up as that hasn't been asked directly (apart from in 2018 as the practical involving yeast which was anaerobic respiration). More specifically, they haven't asked the electron transport chain so this could be asked in the context of photosynthesis or respiration.

As for specific practicals, who knows. Learn them all. They're more likely to get you to apply the practicals in different contexts. I think the chromatography practical has a good chance of coming up.

(edited 4 years ago)

Reply 55

Original post by GCSEStudent903

x

Oh also, do you know if the examiners have wider mark schemes available for other relevant answers, or is it literally just exactly the online mark scheme? Because I can’t help but feel I’ve given an answer that is correct (in a what do you suggest/conclude question) only to not have said what’s written down, which really is just one of 2-3 possible answers imo...I know mark schemes are strict but any idea about this?

Reply 56

GCSEStudent903

Original post by Azeee

Thanks - I never actually did the practical component of a level biology (don’t need it for my offer) so I don’t know exactly all of the 15 different experiments or whatever - do you have any resources that have them all in a list by any chance?

Also do you know the reasons for why we would pick a particular graph (i.e scatter graph vs curve vs line, cos there’s a question on the spec paper like that question 9.2)

You can have a look at the required practicals in the spec on the AQA website.
Also, have a look at the videos here: https://www.youtube.com/watch?v=5-9mn4ZWZ-Y&t=459s

As for graphs, it depends on what the data you have been given is - i.e. if they are discrete or continuous variables. The spec question was continuous variables and a relationship was being explored (between breast cancer and something else if i remember) and so, it would be scatter graph as it's a correlation.

Discrete variables (i.e. categorical data) would be bar charts.

Original post by Azeee

Oh also, do you know if the examiners have wider mark schemes available for other relevant answers, or is it literally just exactly the online mark scheme? Because I can’t help but feel I’ve given an answer that is correct (in a what do you suggest/conclude question) only to not have said what’s written down, which really is just one of 2-3 possible answers imo...I know mark schemes are strict but any idea about this?

Sadly, the mark scheme is "god's word" for these horrible examiners and, sadly, you may have valid points but if these do not relate to the mark schemes then you aren't awarded them. There are cases where an examiner may give benefit of doubt but again, biology is known for having ridiculous mark schemes (hence why the boundaries are so low).

Reply 57

UnknownError404

9

I've been told that the mark scheme the examiners use is far more detailed than the online one and has other acceptable answers based on the responses for that paper. the mark scheme is adjusted multiple times.

^ one of my teachers said this for chem but idk if it's true. sounds reasonable tho so I'd assume it's true. and if it's true for chemistry then it's also true for biology

Reply 58