AQA A-Level Biology Paper 2 [16th June 2023] Exam Chat

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https://river-potato-a18.notion.site/8-The-control-of-gene-expression-24ecbcf4eb3f4e4483a6bd3b00b69868?pvs=4

Life saver!! Thank you so much :smile:

Reply 81

hameedah:)

11

Original post by sb.xo

for hardy weinberg when are you meant to use the p or q as opposed to p^2 or q^2

I think p and q are the frequency of the dominant allele and recessive alleles e.g p=H and q=h
and p^2 is the frequency of homozygous dominant(HH) while q^2 is the frequency of homozygous recessive(hh)

Reply 82

moonlight2460

8

are you expected to know that cystic fibrosis is expressed when alleles are doubly recessive or does the question tell you?

Reply 83

eathsrtbsrtb

7

Original post by moonlight2460

are you expected to know that cystic fibrosis is expressed when alleles are doubly recessive or does the question tell you?

they tell you

Reply 84

ak.xo

7

https://pmt.physicsandmathstutor.com/download/Biology/A-level/Past-Papers/AQA/Paper-2/QP/June%202020%20QP.PDF
for question one, how are supposed to know this, I don't remember learning this in the spec?

Reply 85

belaebela

I predicted viral replication comming up in Paper 1!!

Reply 86

anon25x

12

Original post by ak.xo

https://pmt.physicsandmathstutor.com/download/Biology/A-level/Past-Papers/AQA/Paper-2/QP/June%202020%20QP.PDF
for question one, how are supposed to know this, I don't remember learning this in the spec?

I think it's the Muscles act in antagonistic pairs part of the spec

Reply 87

moonlight2460

8

Hi, do you need to know that the name for the parasympathetic nerve is the vagus nerve or can you just call it the parasympathetic nerve?

(edited 10 months ago)

Reply 88

anon25x

12

Original post by moonlight2460

Hi, do you need to know that the name for the parasympathetic nerve is the vagus nerve or can you just call it the parasympathetic nerve?

Just parasympathetic should be fine

Reply 89

moonlight2460

8

can someone describe the sequence of events of a heart rate through SAN? bit confused with it

Reply 90

fruityoghurt

10

has anyone here bought Miss Estruch's homeostasis pick n mix lesson and not been sent a link to join it?

Reply 91

anon25x

12

Original post by moonlight2460

can someone describe the sequence of events of a heart rate through SAN? bit confused with it

1.
SAN sends wave of electrical activity / impulses (across atria) causing atrial contraction;
2.
Non-conducting tissue prevents immediate contraction of ventricles/prevents impulses reaching the ventricles;
3.
AVN delays (impulse) whilst blood leaves atria/ventricles fill;
4.
(AVN) sends wave of electrical activity / impulses down Bundle of His
5.
Causing ventricles to contract from base up;

Reply 92

moonlight2460

8

Original post by anon25x

1.
SAN sends wave of electrical activity / impulses (across atria) causing atrial contraction;
2.
Non-conducting tissue prevents immediate contraction of ventricles/prevents impulses reaching the ventricles;
3.
AVN delays (impulse) whilst blood leaves atria/ventricles fill;
4.
(AVN) sends wave of electrical activity / impulses down Bundle of His
5.
Causing ventricles to contract from base up;

so the delay is to allow the ventricles to fill. thank you
:yy:

Reply 93

JJ <3

13

Original post by fruityoghurt

has anyone here bought Miss Estruch's homeostasis pick n mix lesson and not been sent a link to join it?

Maybe email her?

Reply 94

fruityoghurt

10

Original post by JJ <3

Maybe email her?

i messaged her on instagram and she accidentally didn't send the link to me, but she's going to send the recording and all the resources so it's all fine now

Reply 95

moonlight2460

8

hi question, do we need to know the mark-release-and recapture equation for estimated population size? I can't seem to find it in the spec

Reply 96

MedApplicantttt

14

Original post by fruityoghurt

i messaged her on instagram and she accidentally didn't send the link to me, but she's going to send the recording and all the resources so it's all fine now