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AS Biology P1 MCQs Preparation Thread

K

Kyusam

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http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_w12_qp_13.pdf
I don't get Q 24 and I'm also confused to what A is, (which is the answer) hmmmm I have a problem in identifying cells in vascular bundles so could some1 please explain to me how this question goes !! Please please please
 
Cesar_malik

Cesar_malik

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Ok in 1
Razo513 said:
http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_s12_qp_11.pdf #16 please i need help on this
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Ok in 16 the ans is c right
This is because active transport require oxygen to work (aerobic respiration for atp) in graph one everything is ok since transport is occurring wwith increase in rate with temp
When u look in graph two u see that there is no oxygen so no aerobic respiration no atp so no active transport so the transport will be very very nnearly zero
Now compare the two on this bases
 
rockerkunal

rockerkunal

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Cesar_malik said:
Threre are 12 amino acids in the question
He says di peptides so we use ^n on the number of peptides in a chain
He says dipepride which means 2 so 12^2 = 144
Ratta this thing coz i did too :p
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hahahaha! sure ill ratta this thing! thats a new formula! loolol so if its a tripeptide, it will be 12^3?
 
Cesar_malik

Cesar_malik

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rockerkunal said:
http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_w12_qp_13.pdf thats the correct link.. ;)
Click to expand...
Thank you at last...pheww
Ok remmb the large hollow balls like :p are alwyas xylem the smaller one are phloem
Look at a diagram of vascular bundle in a book or google it
And in vascular bundle in leaf there is cabium between phloem and xylem with xylem in the inner side while phloem in the outsode
In stem its xylem star middle with pholem outsode and in leaf when theres a hump like in longitudnal i thhink
Towards the bigger hump is phloem and on the down side is xylem still someone check what i wrote
Iam not good at helping other and i dont hav any book right now so its more like 50 50 probability that iam right :)
 
K

kingos3111

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there was a question active transport is it and active transport and diffusion is that correct i wrote answer A is it correct
 
Cesar_malik

Cesar_malik

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zackle09 said:
http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_w11_qp_11.pdf can someone please explain question 24 to me!!
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Ok so if u look carefully he is asking about time taken the valves are closed ok so at first when semi lunar valves are open the atro ventricular valves should be closed use that time and then use the time ventricular vves are open and semj lunar closed since hes asking about both are open are close substract the time u calculated fro total time of heart beat that would be I guess 0.7 soe suppose .2 for semilunar open .1 for semi lunar closed so .3 substract .7 from .3 u will get the time diy iam just explaining as this is a cellphone so difficult to understand the quest :)
 
Z

zackle09

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Cesar_malik said:
Ok so if u look carefully he is asking about time taken the valves are closed ok so at first when semi lunar valves are open the atro ventricular valves should be closed use that time and then use the time ventricular vves are open and semj lunar closed since hes asking about both are open are close substract the time u calculated fro total time of heart beat that would be I guess 0.7 soe suppose .2 for semilunar open .1 for semi lunar closed so .3 substract .7 from .3 u will get the time diy iam just explaining as this is a cellphone so difficult to understand the quest :)
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ohhh no problem i understood it now... Thanks so much :)
 
J

Jinosupreme

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The following events occur during transcription.
1 Bonds break between complementary bases.
2 Bonds form between complementary bases.
3 Sugar-phosphate bonds form.
4 Free nucleotides pair with complementary nucleotides.
Before the mRNA leaves the nucleus, which events will have occurred twice?
A 1 and 2 only
B 1, 3 and 4 only
C 2, 3 and 4 only
D 1, 2, 3 and 4

Anyone help?
Answer is A
 
Cesar_malik

Cesar_malik

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Jinosupreme said:
The following events occur during transcription.
1 Bonds break between complementary bases.
2 Bonds form between complementary bases.
3 Sugar-phosphate bonds form.
4 Free nucleotides pair with complementary nucleotides.
Before the mRNA leaves the nucleus, which events will have occurred twice?
A 1 and 2 only
B 1, 3 and 4 only
C 2, 3 and 4 only
D 1, 2, 3 and 4

Anyone help?
Answer is A
Click to expand...
sugar phosphate bonds never break
free nucleotide are used in dna replication ithink
since there are 2 chains so i think first it unzips(thats one time)then bonds form between mrna and dna(thats 1 time formation of completnery bases)
then thos break between mrna and base(thats second time bond broken) and then formation of bonds with dna complemetry second strand (iguess overall 4 times :)
 
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