✨reaching for a starinthenight:a multiyear gyg✨

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Update - morning of the maths exam
I can’t lie I kinda hate afternoon exams cuz through the day my anxiety is like 📈📈📈
But also like ik I’ve done everything possible
I’ve also just gone through the spec to make sure I haven’t missed anything out that’s like really niche or something
I also don’t really want to do maths rn until the exam (this is why I hate morning exams) so I might just watch someone do a paper
I am really scared but like also I wanna see how much I can do
I mean technically it’s our first public exam cuz we’ve literally never done gcses before
Also heard they’re gonna be super harsh this year with giving out A*s so I’m a bit scared because out of all the subjects I think maths would be the one most likely to get an A*
And I have to get an A* for kings 😭😭
I just feel like getting predicted 3A*s and actually getting it are two very different things
But also at the same time I’ve done 5 mocks at school now (2 in yr12 and 3 in yr 13) 💀 so it should feel fine

Economics and psychology med applicants must be chilling rn 😭😭

Reply 1021

starinthenight2

Biology tomorrow 😫
Maths was acc kinda easy but apparently everyone found it easy so now I’m like grade boundaries 📈📈📈
But yh I’m scared for bio but I’m a little calmed down now that one exam is over 😌 and like I got the feel of what it was like
Normally I have an opinion about the maths papers but this was kinda meh so idk what to say
Question 15 was a big page of writing but low-key it was fine just the very last 2 marker I was like 💀 so yh
Apart from those 2 marks this paper was good

Reply 1022

starinthenight2

Morning of bio exam
Ahhhh I’m so nervous I feel like so much could go wrong at bio just because they pull context out of nowhere apthat uve never heard of and then suddenly u have to apply it
The grade boundary for an A* on this paper 2019 is 76%💀 so it’s low-key very very high (for biology)
I don’t know the tone yet of the biology exams either so I’m nervous for that too 😭

Reply 1023

argentum_ag

Original post by starinthenight2

WHAT THE GRADE BOUNDARY IS THAT HIGH????
now im lowkey even more stressed because if the mark scheme is crazy specific im finished 😭😭😭😭

Spoiler

Reply 1024

starinthenight2

Original post by argentum_ag

WHAT THE GRADE BOUNDARY IS THAT HIGH????
now im lowkey even more stressed because if the mark scheme is crazy specific im finished 😭😭😭😭

Spoiler

For paper 1 ocr bio yh 😭😭
ngl tho that paper was bit tough so I’m hoping the grade boundaries fall
And the ocr paper had no respiration or photosynthesis on there which was just a bit crazy considering this paper focuses on that 💀

Reply 1025

argentum_ag

nahh i just saw that paper 1 aqa bio might have been leaked too 💀
i swear idk what aqa is doing anymore 😭😭

Reply 1026

starinthenight2

Well AQA chemistry….
I think that was a harder than usual paper
But I think I messed up the last ph question and the percentage uncertainty 💀 so I lost 7 marks probs already
But otherwise it was okay
I got x=18 which was the 7 marker and apparently everyone got that so ig it’s right
So I think overall probably harder than maths but easier than bio atm

Reply 1027

starinthenight2

For own peace of mind
Maths edexcel paper 2:
14 marks lost ish not so bad but paper 1 defo went better 💀

Spoiler

(edited 10 months ago)

Reply 1028

starinthenight2

Forgot to update but ocr biology went well I didn’t know what synthetic biology was used for (2marks)
And then I messed up calculating the maximum number of chromosomes or something I put 100 and apparently it was 1024 (2marks) there was a dodgy 6 marker on immobilised enzymes
But yh other than that it felt alright

Reply 1029

starinthenight2

Okay chem AQA was a weird one I’m just going thru the unofficial to see how many marks I’ve lost
Rate determining step (2)
Reagent in test 1 I put dilute hcl (1)
Volume of the gas mixture (2) I inc the the liquid ffs
General formula for Ketene also debatable so I’m gonna put it down as wrong because I rather underestimate (2)
Glucose (3)
Arrow wrong way (1)

Okay I’ve lost like 11 marks which tbf is not to bad so 94
Highest for an A* is 86 so there is some gap in case I forgotten any thing

Spoiler

(edited 10 months ago)

Reply 1030

starinthenight2

Okay maths edexcel paper 3 I think I lost about 15 marks according to uoms
So all in all 92+86+85= 263
Which is quite a bit away from 225 so I think I’m good for an A* in maths (even if the estimations aren’t completely accurate)

Reply 1031

starinthenight2

I’m scared for bio tho 💀

Reply 1032

starinthenight2

OCR biology paper 3 was a horrible paper
Edit after marking : not too bad esp cuz it was meant to be hard also this is based on the uoms someone made
1. Gas exchange/nerves
-smooth muscle then cartilage (2)✅
- ciliated epithelilal cells: waft mucus to throat out of airway (2)✅
-goblet cells: secrete mucus that traps pathogens/dust✅
-autonomic as via medulla oblongata. Rapid, automatic response ie reflex. Idk if u need to specify cranial. (2)✅❌

SA:V= 46(.1): 1 (3)✅
large rate of diffusion of O2 out and CO2 in ✅

2. Respiration
UV light in dark room. TLC plate fluoresces so spots seen as dark spots. (1)✅
Rf = 0.3 (24/80) (2)✅

molecule d is a pyrimidine nucleoside required as a free DNA nucleotide in S phase. S phase (DNA replication) cannot occur without it. Checkpoint detects this and stops interphase. (3)✅
E in matrix, F on inner membrane (2)✅
Tick box: all crosses except tick on the right middle box (the one abt NAD being reduced in link reaction) (2)🤨
Disagree:NAD AND FAD USED TO OXIDISE MOLECULES
-ATP q: some ATP is used for active transport of pyruvate into mitochondria (1)❌
-Coenzyme q: transfer chemical groups between enzymes/reactions eg NAD transferring NAD from matrix to mitochondrial inner membrane. Are recycled in metabolic pathways (3)🤨
Coenzymes bind to an enzymes to change its active site to make it complementary etc
- Graph: Without vitamin C leads to higher adenylyl cyclase activity. Quote data to show this. But, no stats test (or evidence of repeats!) to show that difference is significance so not much confidence in this conclusion. (2)❌❌
I don’t remember that but also I may have misread the graph 💀

3. Maize- genes and photosynthesis
-after 150s, GM plant wastes les energy as heat so more light energy put to light dependent stage. Greater rate of ATP and reduced NADP production. Allows greater rate of RuBP regeneration and thus CO2 fixation(2)✅
-computational biology q: facilitates access to large amounts of data. Can compare sequences and quickly identify allelic differences. more closely related=more similar sequences. (4)✅✅✅❌
-Inheritance cross: should obtain a 3:1:3:1 (or 6:2:6:2) ratio of offspring phenotype. this ratio relates to purple/smooth, purple/wrinkled, yellow/smooth, yellow/wrinkled (total of 4)✅

4.Biodiversity

To get 6 you must talk about For AND Against AND validity . 2 of those= 4, 1 of those= 2
(6)
Points For:
-proportion of measured species endangered falls (quote data) between 2000 and 2020- fig 4.2
-Fig 4.1= fully protected species= lower percentage endangered so could be down to CITES
points against✅
-endangered species in 4.2 rises✅
- species protected by permits still high endangerment. Question how effective permits are✅
Validity:
-don't know if CITES caused these effects or sth else✅
-don't know data before CITES to know true effect. ✅

Genetic bottleneck (1)❌
Behavioural, anatomical, physiological, anatomical(2)✅
Speciation q: could argue both sides. overlapping ranges indicates sympatric, one of the birds on different island so could be allopatric, different habitats so could be allopatric, perhaps alps could lead to allopatric etc- this was a dodgy q, as was the 6 marker (4)✅

5. Respiration

-could talk about similar shape graphs- exponential growth of CO2 production. Maltose always higher than glucose, quote data (2)✅
-at one point overlap so similar (quote data), but one starts off lower than other, than one rises higher than other, sucrose plateaus whilst fructose rises still so not that similar (2)✅
- serial dilution (again!): stir (even distribution), micropipette (greater resolution/lower percentage instrument uncertainty) (2)🤨✅
I think u could have also said clean the pipettes after every use or something
-Gap fill: distilled, stoppered (closed), standard deviations (3)✅

6. A very dodgy q. Have to refer to both homeobox and brain in detail for 6 (6)
- homeobox= control body devlopment. Hox= subset found in animals. ✅
-Hox controls development of body plan along anterior=posterior axis❌
-Hox displays collinearity (spatial and temporal). This means position on chromosome aligns to position of development. Controls what develops where❌
-regulates genes for mitosis/apoptosis. Example of tissue between fingers. Mitosis= grows apopotosis= programmed cell death so tissue degradation✅
-how homeobox functions: 60 amino acid homeodomain sequence, binds to promoter, rise or fall in gene transcription. ❌
-Brain: neurone differentiation regulated. Describe parts of brain and how homeobox allows distinguising of the parts. Brain wrinkling of humans caused by apoptosis- associated with higher thought function❌

7. perhaps eukarya and archaea most closely related cos of histones and SFB+ perhaps archaea and bacteria most closely related cos of no mitochondria and 70s ribosomes (different to eukarya). Cannot conclude which are most closely related. Can conclude that bacteria and eukarya least closely related. (3)✅

DNA polymerase: joins free DNA nucelotides via catalysis of condensation recations that cause phosphodiester bond formation. (1)✅
Helicase: breaks Hydrogen bonds between complementary strand allowing them to acts as templates during DNA replication(1)✅

Edit: I got A A* A*
A IN BIO
BUT YH I GOT INTO KCL MEDSCHOOL

(edited 4 months ago)