AS Biology P1 MCQs Preparation Thread

[sahania]

for part 1 ans is D
part 2 how about the disulfide bridge wont they form bcoz of Sulfur? and H bonds bcoz of the O-H and N-H?
part 3 ans is A

It should be A.... what's the query here ??? let me resolve

 

[XPFMember]

for part 1 ans is D
part 2 how about the disulfide bridge wont they form bcoz of Sulfur? and H bonds bcoz of the O-H and N-H?
part 3 ans is A

part 1...see Q:6 of June 2003..has a similar question..it says ans. is C..plants impermeable to water.... or am i mistaken

 

[Soldier313]

hey can someone pleeeaaaseee help me with these:View attachment 12726

please can someone elaborate

this is the qn, thanx

 

[duh shiekhni]

do the processes exocytosis and endocytosis require energy or not? and do proteins travel by exocytosis out of cells and endocytosis into cells?

exocytosis and endocytosis r active process, they need energy and they dont pass thru proteins! they touch the cell membrane and then the cell membrane forms a vesicle nd the product is engulfed! secondly the bulk food and waste gets through dis process..

 

[Firebender]

http://www.xtremepapers.com/papers/...and AS Level/Biology (9700)/9700_w04_qp_1.pdf

Qs 13 please

 

[sarah.zarrar]

9700/12/O/N/10 question no. 12 and 21

9700/11/M/J/10 question no. 22

9700/11/O/N/09 question no. 13

9700/01/M/J/09 question no. 22 and 28

9700/01/M/J/08 question no. 5

could someone please explain!

 

[Soldier313]

part 1...see Q:6 of June 2003..has a similar question..it says ans. is C..plants impermeable to water.... or am i mistaken

chek out on/11 variant 11
qn 14 ans is D :S

 

[sahania]

qn 1 i don't know
qn 2: u measure the small scale bar i got 6 mm = 2nm
then measure membrane i got 22.5 mm , cross multiply u'll get 7.5 nm
7.5 nm = 7.5 x 10^-9 m
hope that helps, the answer is C right?

how did you get 22.5 ??

 

[XPFMember]

this is the qn, thanx

oh...now i got it..
see for transcription...bonds break..then..mRNA forms..bonds formed...
then these bonds break..and the original bonds form aggain..hence these 2 [i.e. 1 and 2 occur twice...the other 2 option occur once...

 

[duh shiekhni]

I'm confuse with this... the answer is A.. Why not B?

View attachment 12477

its mitosis! mitosis produce two daughter cells whch are identical. that means the number of chromosomes are same. thats y the answer is A. b represns meisois

 

[Soldier313]

how did you get 22.5 ??

check out the attachment

 

[Soldier313]

oh...now i got it..
see for transcription...bonds break..then..mRNA forms..bonds formed...
then these bonds break..and the original bonds form aggain..hence these 2 [i.e. 1 and 2 occur twice...the other 2 option occur once...

what abt the free nucleotides pairing with complementary nucleotides doesnt that happen twice too??

 

[Peter Check]

WHy is B wrong!!!!!?? In prophase chromatin thread coils up to form chromosomes!!!

 

[sahania]

check out the attachmentView attachment 12733

i'm getting 25mm through screen ... anyway..i got the concept ...thank you

 

[duh shiekhni]

PLEASE HELP.
MAY JUNE 06
Q #13 and 17

Please help with thisssssssss!!!!

the answer is A of question 13.
and 17 answer isA.
do you need the explanation?

 

[XPFMember]

what abt the free nucleotides pairing with complementary nucleotides doesnt that happen twice too??

that only occurs once...in the formation of mRNA...cuz when the 2 strands rejoin...it isn't the free nucleotides involved...neither is there any formation of sugar phosphate backbone againn

 

[duh shiekhni]

WHy is B wrong!!!!!?? In prophase chromatin thread coils up to form chromosomes!!!View attachment 12735

prophase is the next process to interphase. during interphase there is replication and formation of chromosomes. but wen the next mitotic cycle starts its just the perpartion of daughter cells to form.
the answer is D. cux centrioles hv to synthesis spindles fibres to separate sister chromatids.
and separation of centromere occurs during anaphase.
hope you get the answer...

 

[XPFMember]

for part 1 ans is D
part 2 how about the disulfide bridge wont they form bcoz of Sulfur? and H bonds bcoz of the O-H and N-H?
part 3 ans is A

disulfide...will be as a result of r group interactions...n i dont think that's possible in ONE dipeptide...what do u say?

 

[Peter Check]

Why is C or D wrong?

 

[XPFMember]

chek out on/11 variant 11
qn 14 ans is D :S

weird