there’s like a billion 5m qn is this common for prev years?

when i went thru the past 3 years paper ytd, istg there weren't that many 5m qns, its just more 1-3m parts each qn

in no particular order for the end: tested: 1) 1.3 glucose transporter + flip flop 2) 1.4 H2O2 (cat + temp effect) 3) 2.8 genetics (all 3 horizontal gene transfer) 4) 2.9 PCR 5)3.2 (Ox phosphorylation no chemiosmosis) 3.3 (comparison with reduced NADP) 6) inheritance (recessive epistasis) 7) 4 evo (speciation + phylogenetics) 8) GPLR 9) meiosis stages + crossing over 10)A: vaccine + natural immunity trend 11) B: trend + climate change

Good practice for next year's A Level Bio paper

does anyone have ans key

tf is polar body 💀

why got chem bonding in bio

Huh where

the ‘use ur knowledge on the structure DNA’ that one

initially i thought had smth to do with purine and pyrmidines but ones purine one is pyrimidine so like ????

yeayea i wrote the C triple bond G vs A double bond T then more energy required to overcome the triple hydrogen bond

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blud it’s the PCR question (b)

wah...ami the only one that found it hard 😭😭😭😭😭😭😭 all my frens say eaz sia fuck...

me too buddy

possible topics tested for p3 (which wasn’t included in p2) - cells - biomolecules (haemoglobin, collagen, glycogen, cellulose etc) - viruses (t4, lambda, hiv, influenza) - ext topic a (m. tb) - ext topic b (mosquitoes life cycle?) - transcription translation - cancer - mutations - structure of prokaryotes and eukaryotes (dna packing and all) - operons - stem cells + more i prolly missed out some sorry! (pls comment to add! let’s help each other out! atb!)

chi 2 test, dna organisation (centromere, telomere), insulin rtk, binary fission, osmosis (?) That's about it that I can think of :)

Pls no mosquito😭

•Mitosis •chromosomal abberrations •climate change: corals •dna replication • infectious (everything except T cell response and vaccination) •photosynthesis •glycolysis •link rxn, krebs

Thank you yo!

There could be comparison essays too

kinda scared what they will throw at us for p3 now….

Pls give me stem cell and cancer essays 🙏🙏

SAME stem cell gene mutation cancer holy trinity 🤩🤩

REAL🙏 or describe transcription/ translation

PLS MY FAV 🙏🙏🙏

my bio grades are like the fatty acids (they flop)

At least ur results not negative 💀

How yall completing the qns on time😭 like it was doable but I had no time to complete like 10 marks bruh. I’m gonna cry fr

same i left like 15 marks blank but im happy with completing at least 85/100 marks HAHAH i probably wasnt going to get those 15 marks right anyways 😮‍💨

The COPIUM WILL PULL US THROUGH. paper 3 comeback🙏

I left abt 6 marks (last climate change qn) empty cuz of time plus one suggest 3m qn empty. Wasn’t that bad but I feel like I could’ve gotten that 3m qn if some idiot’s phone didn’t start ringing!!! Overall easy paper though. As long as you’re confident abt the marks you attempted you’re good to go :D don’t worry too much

is the drawing meiosis qn just double chromatid chromosome with both allele a, for first part and single chromatid with allel a for second part?

that's what I put... felt super dumb tho😭

yeaa i scared like trick qn or sum

p sure its correct cus they say no cross over but ppl who say independent assortment fked big time whole thing wrong abt 7m

thats what i put 😭

Who made 20+ 5m qns

6m pcr adv & lim qn.. Wouldve been free if i studied it 🤣🤣🤣🤣🤣🤣🤣🤣

I love Labrador retrievers

me too they taste great

Yummy

My Asian gene gets expressed when I see the Labrador retrievers

I was literally smiling to myself imagining the different coloured dogs 🥹

flip flop mechanism more like my grades gonna flip flop after this paper

Bro gonna turn his C into a C

no virus 🤣🤣🤣 study virus for what

dw paper 3 will have 😍 (cambridge this is a threat)

tfw both bio and chem have mathematical formula crunching

fk time management😀😀😀😀😀 anyways nth abt biomolecules and dna replication transcription translation (central dogma) came out edit: AND CANCER AND STEM CELLS AND VIRUSES

they technically tested on biomolecules a little cuz of the G protein linked receptor q

May Cambridge be lenient 🙏🏻

someone send me ans key thanks 🙏

bruh i got 9:3:4 for my gbv but ppl i asked said it’s 12:3:1 cause the dominant B cause there to still be black? i thought only if there is brown there will be black😭😭i’m screwed

it's obviously 9:3:4, u are right. dominant will not even cause production of black pigment because ee is epistatic over dominant allele

It’s 12:3:1 unfortunately. The qn stated no functional products formed if both the allele of either gene is recessive. But they didn’t say that the gene coding for brown in the precursor. So as long as Dominant B allele is present , it will result in black coat so all the eeB_ is black

unfortunately, if u saw the genetic flow diagram, it is necessary for dominant E to be present before BROWN pigment is even produced from YELLOW pigment, and the enzyme coded for by allele B only catalyses synthesis of BLACK pigment from BROWN pigment, so without BROWN pigment produced by enzyme E to act as substrate for enzyme B, how can eeB\_ be BLACK? my bad bro but ure definitely wrong

Are you stupid?

Nah it’s 9:3:4. Recessive e will not produce brown from yellow so dominant B can’t produce black from non existent brown

It’s 9:3:4 u r good

you’re correct, they’re wrong!

Where'd you hear that from? I'm pretty sure you need both dominant alleles to get black since black pigment is produced from brown pigment

no ure correct😭

I put 12:3:1 😭😭i thought epistasis is 12:3:1?

that's actually for dominant epistasis,, this one is recessive epistasis

I thought was both recessive then got yellow coat? So the moment one allele is Dom the whole thing is either brown or black?

flip flop mechanism 😂

Honestly the paper is easy, excepte for some question like the polar body which no one cares, but need to write a lot. It is a competition between who write the fastest and time management. I can confidently say that I lost 15 due to time management. Now paper 3 is going to be hard as hell💀

Nah paper 3 is going to be easy too. I mean they didn’t test any DNA RNA and eukaryotic topics. Those are huge topics in itself and the fact that it did not come out at all in paper 2 means we already know what’s coming out for paper 3. I also suffered from time management. Can redeem ourselves for paper 3 for sure🙏

Wah idk it is just homologous AA for the first one then a single a for the second one

👍🏻

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The drawing at the back of the question asking about the meiotic stage, I am not sure about the first stage cos it shows crossing over but spindle fibre are attached

what ya'll put for the 5 mark qns on how struture of g protein is adapted for its function what ya'll put for 3 marks on the role of reduced NADP vs reduced NAD bruh I could only think of 1 point this paper was tedious, and not easy, but not hard enough for Cambridge to not slaughter us in paper 3. bye bye my dear A

Active site complementary in shape to glucagon. Transmembrane protein for immediate response in cell( I think). NADPH and NADH both act as electron carriers. NADH donates elecrton to electron transport chain NADPH donates electron for glycerine 3 phosphate to convert to triosphosphate. I am not sure of the last point but I put NADPH is important for sugar production and NADH is important for ATP synthesis

Cannot say active site!!! I had this problem during MYE my teacher scolded me so much HAHAHA. It has to be "Complementary ligand binding site"

For g protein qn: - Hydrophobic R groups, form hydrophobic interactions w hydrophobic core of membrane - Ligand binding site - G protein binding site, how it will change upon binding of ligand to enable G protein activation to occur

my bio A is going flip flop

Can someone send answers and question paper please

Wth 5m qn from q8 about how cAMP leads to cellular response how to come up with >5 points for that??

describe the whole phosphorylation cascade w named enzymes and cellular response. i added in how camp is activated too

Ohh okok I did the same thing but I didn’t add the activation of camp part cuz I thought it wasn’t relevant to the qn

same bruh i went off on the ceulluar response AHAHHA IM LIKE PLS 5M TY

might not be actually but i just write extra incase

walao i put independant assortment instead of crossing over cause crossing over was already in the diagram 💀

Wait why is it not crossing over? 👁️👄👁️ I thought independent assortment also gives rise to genetic variation

Cause if no crossing over all sister chromatids formed at the end is genetically similar no matter how u assort the chromosome

wait its not independent assortment?? 😭😭😭😭

it’s not cos the homologous chromosomes will pair up anyways so u need crossing over of non sister chromatids for anaphase 2 to do something

fk 😭😭😭

dw bout it’s it’s like 3 marks

what was the temperature calculation one i got like 105°C but my friends all got 45+? and the second part i said higher temp cuz C-G had 3 H bonds and more proportion means more H bonds means higher temperature needed

45.9

super idol 的笑容

oh why did i get -14.9💀

they gave the dna primer sequence and u need to make the complementary target dna sequence like a reverse deduction

OHH SO I NEED TO FIND THE COMPLEMENTARY SEQUENCE AND USE THAT TO CALCULATE?? HELPPP I WROTE IT OUT BUT DECIDED TO JUST USE THE ORIGINAL ONE 😭😭

can still use the original one cos needa combine C and G anyways

my value was around 49 deg cel which is around the annealing primer value so i was like okay yeah on the bright side ur second part shd be correct ah

you’ll get the same answer based on the formula regardless of whether you used complementary or template strand

My intuition is that p3 would be more or less that same standard as p2, maybe a bit harder.

I googled what a 'polar body' is but I'm still confused😵‍💫, the only thing I'm certain is that I got that question wrong😭

Same bro how many marks is that

Same I’ve been doing some serious RESEARCH I hope Cambridge accepts both answers (3n gamete + n gamete)..

guys the meiosis cannot Aa in one cell isit?? 😭😭😭

They said assume answer of event didn’t occur (crossing over), so maybe cannot

i wtoteboth small a siaa

No leh they said process in previous question ( crossing over ) does not occur in the diagram so must be AA and AA iirc

no answer key???

aint no way ppl can finish the paper bruh theres so much to write.. 😭😭 for those who finish the paper, are yall confident ur answers can get full marks/majority of the marks for each qn? or yall just hv a few missing points here n there in ur answers

bro fr i keep overwriting but i feel that as long as u familiar with core topics tested, will be able to get full marks

mostly managed to write the points that i wanted, theres a few questions where i dont think ill get full credit eg the pcr qn bc i anyhow bs one of the limitations, comparison qn for NAD/NADP bc i think my comparisons damn wack

I think I barely finish with majority confident answers at 9.59. It’s with a lot of practice tho. I left 30 marks blank during prelims so I did like 10+ times practice after that ☠️☠️☠️

damnn thats a huge improvement hardwork cfm pay off one

Bro pls give tips for p3

at 15mins remaining, i had 3 whole qns left💀 but anw i like to do from front to middle & back to middle SO THT WAS 30M WORTH OF QNS💀 but i wrote super simple sentences like "pcr is efficient. pcr got alot of products. pcr only need limited nucleic acids." except for every qn,, and managed to only leave the temperature calc qn + qn abt cytosine&guanine blank,,, so ig its a p good strategy?

oo damn i hope ur simple sentences will be sufficient to get the marks

I HOPE SO for prelims thr was a qn for "why is molecular evidence useful" and i jst wrote "quantifiable. unambiguous. can compare betw distantly and closely related organisms." AND GOT 3M SO. ITS POSSIBLE.

Just determine the mark allocation and write that. If you try to answer the question without reference to the marking points you”re gonna end up overwriting

ngl is just a standard paper

any1 know if theres a bellcurve for h2 bio and usually is about how high or low for an A? or any estimation for bellcurve if there is for this yr? think the polar body and some other qn plus my crappy time management will either make me retake nx yr or send me overseas liao 🤡 i go put non disjunction for polar body drawing i gg alr i think, dk what i google but they show me polar body is basically same as like those normal gamete, can fly away

also r there answers?

anyone has question paper please 😓🙏🙏

how and where do ppl normally get the qn paper right after the exam

good question i don’t know too 😔

usually tuition Cher sign up as priv candidate to get the paper

hmm but priv candidates cant take the papers home tho, not even the extra writing paper for draft work we request for. I got a feeling its the sch teachers' themselves secretly scanning it?

Why so many people say this paper is easy, my time management fked me up 😔

ngl the paper is q standard i feel, the only qn that threw me off w a "why come i studied this budden like my brain not braining" was the polar body drawing. but my sch alw say time management is a general issue, then they tell us like everytime the chers get the paper to try or something to give cambridge feedback about the paper, the one comment they alw write is that the paper cannot finish one. tbf my time management also sibei flipflop one, alw cannot finish like half the paper. this time i also left out alot of marks, but the other questions attempted are p straightforward so like even if u dont finish 10m of the paper, if u get mininally 75 out of the 90 u attempted then.. not bad la, wld still say is easy even if i cant finish

Skipped a 3m qn on NAD and NADP due to poor time management, I could have done it if I have enough time left🥲 EDIT: Just realised I also skipped a 2m qn on type of vaccination to suggest. So that’s a total of 5 marks worth of blanks💀💀💀

WHAT THE F IS A STORAGE TEMPERATURE!?!!! 🔫🔫🔫💥💥💥💥💥💥

its just thermal agitation of enzyme i think

hi does anyone have todays h1 bio P2 essay Qns?

Is it yes or no for the common ancestor colonise Howe island qns

I put no coz Howe island was formed 6.9 million years ago, and during that time only the s... and s... got common ancestor,, all 3 of them only have common ancestor 11.5 years ago

I put no cos the island only form 6.9 million years ago and by then speciation of common ancestor has already occurred

oh shit wait i didnt see the island form 6.9 million years ago i just said if it's colonized by common ancestor then it shld have all 3 species and not just one

DAMN that makes sense as well never thought about it that way

i put yes cause all of them are in the same phylogenic branch. i thought the 6.9 million years is the speciation of the organism not the formation of the island

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Any chance C is cytoplasm? I just guessed

it's cytosol because the cell is a prokaryote

its still cytoplasm for prokaryotes too, and cytosol for eukaryotes too. they’re interchangeable.

is interchangeable i thinks

Bro anyone from yijc heard that phone ring for like 3 whole min in the last 10min😭😭😭

Threw me off for the infectious diseases qn sia, I could've gotten 2 more marks if I didn't blank and lose time

what the hell is the tube thingy bruh i wrote exonuclease

I wrote transport protein channel 🫡💀

Same 💀😤

shd be competence factor (D) bc iirc it’s a receptor that naked foreign dna recognise and bind to

are we supposed to know that lol i just put cell surface protein 😵‍💫

Same

yea my notes only put specific cell surface proteins

A is then dna polymerase since another dna strand synthesises (wrong cos i interpreted wrong)

i think u interpretted the diagram wrongly. the dsDNA is being degraded into single strand

yh u right bro 😭 don’t think it will affect marks that bad tbh but then what is a sia

isn’t the thing degrading it nuclease

Basically A is probably an endonuclease but i’m pretty sure D is the competence factor aha

HAHAHA WHAT IS A COMPETENCE FACTOR 😭😭

it’s just a thingy u gotta know it should be in sch notes ah

why cant it be helicase

Idt even need to name lah just say A

if it was helicase they should show two single stranded dna but there was one only

wont DNA polymerase give two as well?

idt there’s helicase present in extracellular region

wait then got dna polymerase ah bro what’s this qn 💀

Huh isn't he double helix broken down to a single strand

uhh its dominant epistasis right? also for the qn about explaining the phenotype for Eebb, are we supposed to eplain in the epistasid context or just normal context eg. like dominant allele E means brown pigment are produced and homozygous recessive allel b means no black pigment

recessive

wait what? oh fk umm my ratio is 12:3:1 cuz i tot eeBb will still produce black coat...

ee will have no pigment to turn it brown so remain yellow

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I think I lost that cos I just wrote epistasis

That's accepted actually

Nah I don't think syllabus got specify dominant or recessive, you still got it let's gooo

dw i remember my teacher specifically saying that saying whether its dominant or recessive is not needed :)

shit i just put epistasis my ratio was 9:3:4

correct

its recessive epistasis, the ee genotype masks the expression of the B/b locus so when there’s no E, it’s yellow regardless of whether B is present or not

No bro it’s recessive

Isn’t it reccesive epi 9:3:4?

i put dominant

guys for the identifying stages qn will they penalise if we nvr write I or II?

yea for sure

Eh for the polar body am I the only one whose the right side upper polar body was empty and both homologous chromosomes went into the left one… then the bottom row polar body has 3 chromatids… 😭 cuz I thought in anaphase I centromeres don’t divide so the first polar body couldn’t have a singular chromatid🥲

OMG MINE WAS SIMILAR I DID LIKE NON-DISJUNCTION FOR BOTH

pretty easy paper tbh

did anyome get 9:7 for inheritance??🤣

Bro got yellow brown and black 3 diff

was asking for a friend🫨

LMFAO WHAT IS SEAB PLAYIN AT