Sorry ... I meant variant two http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w09_qp_12.pdf
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A level Biology: Post your doubts here!
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Qs number again
Sorry,sorry.Ya Allah Mn xD
i was just gonna comment
23 and 27Qs number again
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its okay
check ur wall
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Sorry i accidentally uploaded s12 paper.
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w12_qp_13.pdf
Question 4 please
No prob,I accidentally gave the wrong varaint.XD
Ohkay so..you know the formula Magnification=Size of Image/Size of Object.
In the question magnification is ×20 000.You can get the size of Image by using the diagram.I got it as 60mm which is 60,000µm
Place the values in the formula
60,000µm/×20 000 = 3
So the answer is B which is 3 × 10^0µm.
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I've read somewhere that it is normal for cell to lose some amount of telomeric DNA in each round of cell division...and furthermore, when the telomere length is dropped to a critical point, a signal is given to stop further cell division.
So, it seems like a normal cell division will need something to replace telomere to carry on replication, therefore Answer A is the correct one.
For the next question: When the sister chromatids separate at the centromere, approaching the opposite poles, distance between chromatids and poles decreases----->stage is anaphase. Distance between centromeres of the sister chromatids increases as they are leaving each other, going away from each other. So the answer is A I guess, I didn't check MS
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answer is A right?
Because since it said keh DNA has 120 nucleotides so then MRNA has only 60 nucleotides.
And 3 codon code for 1 protien so the number of amino acids would be of 20 i.e 60 / 3 .
Hope it answers
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C answer?
If the answer is C then because the data says that the bacteria was allowed only ONCE to replicate in medium with N 14 .So Alla the DNA molecules that were N15 before would all have their complementart base pairing with N14 necloetides
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Double stranded DNA contains 120 nucleotides. During transcription, only one strand will be transcripted, so one strand of DNA contains 60 nucleotides. mRNA will also contain 60 nucleotides. Each amino acid contains a trilplet code of 3 bases (nucleotides). So no. of amino acids in the 60-nucleotide-long polypeptde will be : 60/3=20 amino acids
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YOur most welcome but what about the other question? was i right?0.0
Yes it is C.But I don't understand.
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which part do you not understand?0.0
Look. The DNA was at first with N15 isoptpe in it right? Now that DNA is Allowed to replicate in a medium of isotope with N14( think of them as nucleotides) Now all the DNA which had N15 would replicate ..And the free nucleotide available are of only N14 since that is the medium.
YOu remember the concetp of semi conservative replication? So the N15 DNA unwinds itself and the N14 nucloetides attach themselves to the DMA molecule adn DNA N14 and 15 combine together.And since the replication period was only ONCE so only hybrid DNA would be available.
Get it?