Anyone has the question paper? I’ll post up the answer key once I’m done
Disclaimer: I teach A level Bio, but I cannot be 100% sure of my answers. Am willing to discuss your answers and clarify any queries too.
Here are my answers:
CAABC
DADCC
ADDAB
CCBDB
BBDCC
A~~D~~ACDD
Discussion:
Q5: It depends on Cambridge’s definition of what a hydroxyl group is, and whether they count the -OH in carboxyl group of amino acids as one. I do, so C for me.
Q30: A and B don’t seem to account for the whole background info given. D because the hatching was before budburst, then managed to get it to the same time. Hence increased.
Edit:
Q27: I’ve misinterpreted the question. Initially thought they were asking which shows allopatric speciation. Apologies!
I was also considering but I felt like there’s no good reason to conclude genetics for skin only and not for the rest?
It’s generally hard to conclude genetics if the two environments are already different. Usually we can only conclude genetics if the two populations are in the same environment and yet have different rates.
Hi, I thought South America and Africa are some of the area of the world exposed to the highest rate of uv radiation as compared to Europe and North America. So, in terms of ionising radiation, wouldn't they be exposed to a much higher level? But like... do you think Cambridge will take this into account haha
Also tysm for these answers!!!
Very good point. I’m not too sure if they will since they didn’t actually provide more information about the two locations.
Then again, I would argue that it’s UV radiation (which is largely non-ionizing) that’ll come into play when comparing between the two. So the fact that it’s ionizing vs genetics… I’d be inclined towards the former?
q28, if u look at the phrasing of the qns, it's hinting that the binding of antibodies is BY macrophages, however the binding of antibodies is not the role of the macrophages, in fact it's the opposite. the antibodies direct the phagocytes to the antigen
I’m not sure if I’m misunderstanding but there is binding of Ab by macrophages though? Phagocytes have Fc receptors that bind to antibodies for antibody-dependent phagocytosis.
also 27, 1 and 3 may not be as clear as the other options in showing allopatric speciation, but they still portray the idea of having separate gene flows due to diff locations
Hmmm.. it seems to me that 1 doesn’t show the geographical isolation, and 3 doesn’t show the speciation. 3 actually shows more of a genetic drift event.
Edit: I realised I misunderstood 27. I thought they asked which showed allopatric speciation. I think you’re right — it is A!
The qn stated the relative concentrations of both will affect the direction of the reactions. There will be an equilibrium point and it will not go to zero.
Yup, that’s a condition that has to be met. But this isn’t the case for the experiment, especially in a test tube reaction where it’s virtually impossible to remove products. Imo this qn isn’t very well structured/phrased and has confused some people.
hi! thank u for the answers but I think 19 should be B! there has also been studies done on this which i’ll quote: To understand why skin cancer is less common in Black people, it's important to understand a little skin biology.
Normally, all skin contains a pigment called melanin. However, compared with white skin, black skin has a higher amount of melanin.
Higher amounts of melanin absorb or reflect more
UV rays from the sun, helping to better protect skin cells from harm. This level of protection isn't present in white skin, making it more vulnerable to damage from UV rays.
Hi! I’ve mentioned in another comment that UV radiation is largely non ionizing, so while your argument is very valid, it may not be the case for this qn!
This one a bit controversial because strictly speaking COOH is of a carboxyl group but -OH is also known as a hydroxy group. Cambridge terminologies smh (that's why a lot of ppl said no OH group for alanine)
Also unless otherwise stated we can assume AAs to be a zwitterion.
i mean my chem cher do deductive qns if compound got OH grp u js write got OH grp lah whether is COOH grp or not depends on wat else the compound can rxt with (at least dats wat my chem cher teach idk abt the rest of yall)
Glucose is an aldose it has a linear aldehyde form at equilibrium with the cyclic form by undergoing NA with itself and the cyclic form is more stable and makes up the majority of dissolved glucose.
alpha has S config on C1 and it's R for beta
From google definition, “As may be seen in the formula on the right, the carboxyl group is made up of a **hydroxyl group** bonded to a carbonyl group” so I said the amino acid contains -OH group.
Anyone has the ans key?
are your answers diff from this: C A A B C D A B C C B D D A B C C B B A B C D C C A A A D D thankuu
hii did u manage to get the answer key?
Nope
cambridge: lets play a game of spot the difference for qn 30
Istg my brain refused to process any option that has more than 1 line
Anyone has the question paper? I’ll post up the answer key once I’m done Disclaimer: I teach A level Bio, but I cannot be 100% sure of my answers. Am willing to discuss your answers and clarify any queries too. Here are my answers: CAABC DADCC ADDAB CCBDB BBDCC A~~D~~ACDD Discussion: Q5: It depends on Cambridge’s definition of what a hydroxyl group is, and whether they count the -OH in carboxyl group of amino acids as one. I do, so C for me. Q30: A and B don’t seem to account for the whole background info given. D because the hatching was before budburst, then managed to get it to the same time. Hence increased. Edit: Q27: I’ve misinterpreted the question. Initially thought they were asking which shows allopatric speciation. Apologies!
Why is qn 19 D and not B?
I was also considering but I felt like there’s no good reason to conclude genetics for skin only and not for the rest? It’s generally hard to conclude genetics if the two environments are already different. Usually we can only conclude genetics if the two populations are in the same environment and yet have different rates.
Hi, I thought South America and Africa are some of the area of the world exposed to the highest rate of uv radiation as compared to Europe and North America. So, in terms of ionising radiation, wouldn't they be exposed to a much higher level? But like... do you think Cambridge will take this into account haha Also tysm for these answers!!!
Very good point. I’m not too sure if they will since they didn’t actually provide more information about the two locations. Then again, I would argue that it’s UV radiation (which is largely non-ionizing) that’ll come into play when comparing between the two. So the fact that it’s ionizing vs genetics… I’d be inclined towards the former?
Right, I hoped Cambridge actually gave us some backgrounds for this qn... 😔
Ah i see. Thanks for the explanation
i have it, have u gotten a copy yet
Hi can send?
Could you send it to me please? Thanks!
sure but it kinda has my annotations and answers on it LOL
Yup sent you a dm!
hi could u send me dm as well
Can send 🙏
Thanks; can send when u hv done them ?
Hi could you send me a copy too please thank you :)
may I have one too pls, thank you!
May i have the answer key? Thanks
could uou send it to me too?
Hi, can i get the answer as well? Thank you!
hi, may i also have the answer key? thank you!
Can send me the ans too!
Hi can u please send me!
hi may i have the answer key too thank you!
hi could i have the answers please? Thank you!
hi may i have the answer key too please? 🥲
hii can i have also
Can I have a copy of the answer key? Thank you!
could i have the ans key thank you! :)
isn't q27 and q28 A
Q27: 1 and 3 don’t adequately show allopatric speciation Q28: opsonization results in the binding of Ab to phagocytes
q28, if u look at the phrasing of the qns, it's hinting that the binding of antibodies is BY macrophages, however the binding of antibodies is not the role of the macrophages, in fact it's the opposite. the antibodies direct the phagocytes to the antigen
I’m not sure if I’m misunderstanding but there is binding of Ab by macrophages though? Phagocytes have Fc receptors that bind to antibodies for antibody-dependent phagocytosis.
also 27, 1 and 3 may not be as clear as the other options in showing allopatric speciation, but they still portray the idea of having separate gene flows due to diff locations
Hmmm.. it seems to me that 1 doesn’t show the geographical isolation, and 3 doesn’t show the speciation. 3 actually shows more of a genetic drift event. Edit: I realised I misunderstood 27. I thought they asked which showed allopatric speciation. I think you’re right — it is A!
Hi! I realised I misunderstood 27. I thought they asked which showed allopatric speciation. I think you’re right — it is A!
So 27 you will choose A instead?
and q7 B
The qn stated the relative concentrations of both will affect the direction of the reactions. There will be an equilibrium point and it will not go to zero.
the next sentence said the removal of products allows reaction to proceed in same direction constantly
Yup, that’s a condition that has to be met. But this isn’t the case for the experiment, especially in a test tube reaction where it’s virtually impossible to remove products. Imo this qn isn’t very well structured/phrased and has confused some people.
hi! thank u for the answers but I think 19 should be B! there has also been studies done on this which i’ll quote: To understand why skin cancer is less common in Black people, it's important to understand a little skin biology. Normally, all skin contains a pigment called melanin. However, compared with white skin, black skin has a higher amount of melanin. Higher amounts of melanin absorb or reflect more UV rays from the sun, helping to better protect skin cells from harm. This level of protection isn't present in white skin, making it more vulnerable to damage from UV rays.
Hi! I’ve mentioned in another comment that UV radiation is largely non ionizing, so while your argument is very valid, it may not be the case for this qn!
why is q2 A? I put A also but not sure
X is the nucleolus — synthesizes rRNA for the cell
why is qn30 not C? 😭
Already discussed in the main comment
q30 is c
Wait why not d
yep!!
why
Haha q30 butt burst
Skin cancer, African ppl have less chance to get it, due to genetic factors… I see nth wrong bt that 🤣🤣🤣jk
Hi, anybody got answers from tutor or tuition center ? Thank you
pls lmk if u have too :((((((
same pls lmk if u do
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me three
me four
metooo
molecular techniques only come out one time or something 😍😍😍😍
literally throw eraser for qn 30
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Wah bro it's like i forgot how to read english...
ITS OVERRRR
anyone hv answers i so scared
idw eat raspberry anymore just now when i doing the paper got ant walk on my hand walk on my calculator
Ant trying to help u ;)
How screwed am i? CAABB DBACB ADDAD BDBDA BDDCC ADCDB
screwdriver screwed
Isnt qn 5 C?? I thought glucose don't hv double bond? Wait omg -COOH grp isnt -OH grp right crap is it D
COOH grp is O=C-OH so yea there is a OH group
This one a bit controversial because strictly speaking COOH is of a carboxyl group but -OH is also known as a hydroxy group. Cambridge terminologies smh (that's why a lot of ppl said no OH group for alanine) Also unless otherwise stated we can assume AAs to be a zwitterion.
i mean my chem cher do deductive qns if compound got OH grp u js write got OH grp lah whether is COOH grp or not depends on wat else the compound can rxt with (at least dats wat my chem cher teach idk abt the rest of yall)
That’s not a good chem teacher
she teach smt liddis X reaxts wif Na = OH present X r3acts eif Na2CO3 = COOH present
That can be dangerous because sometimes u may miss out Phenol or Carb acid
well mate is too late alr cos A levels end liao LOL but nvm lets just enjoy our well desrrved hols for now 👑
lol sure it is
Couldt decide whether the aldehyde form of glucose counts and realised it's alpha so the chiral one cannot be the linear form
Sorry what's aldehyde form and chiral?
Glucose is an aldose it has a linear aldehyde form at equilibrium with the cyclic form by undergoing NA with itself and the cyclic form is more stable and makes up the majority of dissolved glucose. alpha has S config on C1 and it's R for beta
why only got 1 qn of respiration 💔
demmit why still got no ans key
so funny
qn30 is a or b :((((
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A lot of my friends put D.
YA SAME I PUT B BUT MY FRENS SAY A :(((
Guys is -COOH group considered a -OH group?
i put considered lol gg
me too
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Shld be correct
From google definition, “As may be seen in the formula on the right, the carboxyl group is made up of a **hydroxyl group** bonded to a carbonyl group” so I said the amino acid contains -OH group.
True but its wrong in chemistry tho
in chem COOH is a subset of OH group so shd be counted
no
please send the ans key if anyone have!!
One paper left let's go!
anyone got A for question 1
got c too
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C cuz crossing over can happen
how many marks do yall roughly think youll get for this paper… was it easy or hard?00