AS Biology P1 MCQs Preparation Thread

[geek101]

In a genetic engineering experiment a piece of double-stranded DNA containing 6000 nucleotides
is transcribed and translated.
What is the total number of amino acids used?
A 500 B 1000 C 2000 D 3000

Please explain.

ok since the DNA has 6000 nucleotides and their are an equal number on each strand (2 strands) so each strand will have 6000 / 2 = 3000 nucleotides. The mRNA is constructed from one strand so the nucleotides on the mRNA is also 3000. Now a codon consists of 3 nuclotides and each codon represents one amino acid....so the number of codons/amino acids = 3000/3 = 1000....so the answer is B.

 

[Paparazzi478]

http://www.xtremepapers.com/papers/...nd AS Level/Biology (9700)/9700_s11_qp_11.pdf
heyy can anyone explain QUESTION 20........ still confused about the concept of mitosis ans meosis
THANKYOU

 

[eyamwir]

is it okay if i just do june papers only? because i don't feel like studying all october papers at all. -.-

 

[Soulgamer]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s11_qp_11.pdf
heyy can anyone explain QUESTION 20........ still confused about the concept of mitosis ans meosis
THANKYOU

This question is based upon genetic engineering. You might remember it from O-levels. Now V is obviously a haploid(13) in number as it is an unfertilized egg. The cell taken from the frog or in any case of genetic engineering will be diploid as they want to create an embryo and further on a frog, so W is 26. X is diploid as the nucleus was destroyed by UV light so the cell regains it's diploid number 26.

 

[Soulgamer]

is it okay if i just do june papers only? because i don't feel like studying all october papers at all. -.-

I'd advise you to do them as you still have alot of time, 4 freaking days. MCQ's are repeated from everywhere whether it is May/June or Oct/Nov. Plus by not doing them you'll disrespect the people who appeared in Oct/Nov

 

[raamish]

http://www.xtremepapers.com/papers/...and AS Level/Biology (9700)/9700_s05_qp_1.pdf

qs 5) the sucrose solution is 0.25 so its almost dilute so wouldnt water go into the mitochondria and cause it to burst because of excess water?

 

[rogue94]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s05_qp_1.pdf

qs 5) the sucrose solution is 0.25 so its almost dilute so wouldnt water go into the mitochondria and cause it to burst because of excess water?

I guess not, since it depends upon the water potential inside the mitochondria, which must be about the same as that of the solution in which they are placed. The correct option is therefore C as the solution prevents (significant) net movement of water into or out of the mitochondria (preventing any change in their structure.)

 

[raamish]

I guess not, since it depends upon the water potential inside the mitochondria, which must be about the same as that of the solution in which they are placed. The correct option is therefore C as the solution prevents (significant) net movement of water into or out of the mitochondria (preventing any change in their structure.)

right ty

 

[Haniya Khan]

ANYBODY THER?

 

[fathimaash]

ANYBODY THER?

yes.....

 

[Haniya Khan]

PLS HELP ME IN OCT NOV 2002 MCQ 30, AND 32
MAY JUNE 2003 MCQ 4,7,18,19,

 

[Haniya Khan]

PL S HELP

 

[fathimaash]

M.J.03
q4-onli wen initial/final legth=1 da concentration of sucrose solution, in moldm–3, has the same water potential as the cell sap

before immersion so wen inital/final =1 da sucrose soln is 0.45
q7- i couldnt do it bcoz i hv my paprs in da computr sry!!
q18- sinc da polypeptide chain contain 10 aminoacid 10 tRNA molecules r requird to translate it
q19- A, B, and D r completely out obviously it should be C.
A- show N15 increasin which is wrong it should decrease
B- shows N15 is neithr increasin or decreasin which is again wrong
D- shows da

 

[fathimaash]

dat N15 is becomin zero dat means its not replicating semi conservatively
so option left is C

PLS HELP ME IN OCT NOV 2002 MCQ 30, AND 32
MAY JUNE 2003 MCQ 4,7,18,19,

O.N.02
q30-find da ventilation rate for 4mins d highest is da answer
eg; 14*0.6=8.4 which is da ventilation rate den multiply by 4 mins = 33.6 do dat for all 4 option da one which gves da highest s da answr
q32- not sure

 

[Haniya Khan]

thnku so much

 

[Haniya Khan]

but may 03 mcq 18 ans is c ?

 

[aliya_zad]

http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Biology%20(9700)/9700_w11_qp_12.pdf
how do u do Q39??
pls Help!!

 

[fathimaash]

but may 03 mcq 18 ans is c ?

sry no its A k here dey ask for da minmium no tRNA molecule requird sinc here dey say dere is onli 4 different kind (although 20 amino acid onli 4 kinds) so onli 4 tRNA. sry!!!

 

[Haniya Khan]

no prob. thnku

 

[fathimaash]

no prob. thnku

ur welcum...