AS Biology P1 MCQs Preparation Thread

[Soldier313]

aoa ..
need help with this

View attachment 12819

p53 prevents replication of damaged DNA, the mutation of this gene will mean abnormal and uncontrolled growth of damaged DNA hence cancer

 

[kinglynx]

Hey guys quick question, what are the relative bond strengths ?
like hydrogen , ionic, disulphide bonds and hydrophobic, whats the most to least? and how do you break each one? THANK YOU ! <3

 

[thu]

Good luck y'all. Our last hours to freedom! (i mean if u only have this pp left, like me )
im off to bed with biology dreams..

 

[confused123]

I bet tomorrow's paper is gonna be a killer. The trend has changed since S09. Just hope for there are more repetitions in the paper Anyways, all the best for tomorrow's candidate !!! Me as well

its good to be scared but its not good to make others feel the same way, good luck 2

 

[oldfashionedgirl]

Someone please explain me question 33. The answer is A;

http://www.xtremepapers.com/papers/...nd AS Level/Biology (9700)/9700_w10_qp_12.pdf

 

[geek101]

Can someone please help me with these?
View attachment 12779

View attachment 12780
^can someone please label each of the parts for me?

View attachment 12781
^why C and not B?

which component of tobacco smoke causes emphysema?


jazakallah

1) when mitosis occurs the daughter cells are smaller than the parent cell, they grow in the inter phase, so 2 and 3 are right only.
2) D are the xylem cells, thick walls..and on the inner side...
C are neither phloem nor xylem they are just there for division
A are the cells in the pith
and then B will be phloem
3) nitrifying bacteria convert ammonium ions to nitrites then nitrates....these are compounds of nitrogen so C
B are nitrogen compounds in plants, these are amino acids....which is not done by nitrifying bacteria

 

[aom]

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

its D right?? because the centerioles moove apart to prepare for spindle fibres to be formed ...

 

[aom]

Why is C or D wrong?View attachment 12736

because its not a must .... i mean maybe both ventricles and atria are relaxing at the same time so the pressure will not be higher in the atria ...

 

[Soldier313]

1) when mitosis occurs the daughter cells are smaller than the parent cell, they grow in the inter phase, so 2 and 3 are right only.
2) D are the xylem cells, thick walls..and on the inner side...
C are neither phloem nor xylem they are just there for division
A are the cells in the pith
and then B will be phloem
3) nitrifying bacteria convert ammonium ions to nitrites then nitrates....these are compounds of nitrogen so C
B are nitrogen compounds in plants, these are amino acids....which is not done by nitrifying bacteria

thanx sis but for qn 1, the ans says the only right statement is 2:/

and also the last part i asked which component of tobacco smoke causes emphysema ?
thanx again

 

[confused123]

LOL my bad!! i didnt focus well

it happens. read slowly n carefully each question. simple but effective tip. hope we can apply in exam 2

 

[geek101]

thanx sis but for qn 1, the ans says the only right statement is 2:/

oops my bad, semi conservative replication has nothing to do with mitosis, it occurs in the interphase..

 

[aom]

hmm i don't know i still feel that the answer should be all 3 : hydrogen, disulfide and peptide :/

guys its only peptide , because disulphide is between S-S so the bonding between the S's and in the pic the H is on the outside... so it can't form disulphide

 

[confused123]

Water is like a government soldier it comes in to cells and leaves as it likes to ... in a turgid plant cell it is practically 'full' of government soldiers so no room for extra soldiers so the soldiers are RESTRICTED to enter the cell. But at first the water enters the cell through cell wall so cell wall is permeable to water.
But in an animal cell no cell wall for water keeps entering the cell till it bursts :/


In your second choice without Hcl the colour is orange but with HcL the colour is green. In order of increasing intensity of reducing sugar in a solution orange shows a higher intensity of reducing sugar. So since after boiling the intensity actually reduces ( from orange to green) it cannot be a non- reducing sugar. If a non-reducing sugar was present the colour would be brick-red becuse more reducing sugar will e available.

Thank-you Mr. Government Soldier for a cool explanation.

 

[Soldier313]

oops my bad, semi conservative replication has nothing to do with mitosis, it occurs in the interphase..

thanx but again i have a qn if u don't mind what exactly is nuclear division and how is it different from mitosis?

 

[kinglynx]

Hey guys quick question, what are the relative bond strengths ?
like hydrogen , ionic, disulphide bonds and hydrophobic, whats the most to least? and how do you break each one? THANK YOU ! <3

 

[geek101]

thanx but again i have a qn if u don't mind what exactly is nuclear division and how is it different from mitosis?

Nuclear division is a general term, basically the dividing of the nucleus. It can either be my mitosis or meiosis (reduction division)

 

[Soldier313]

Nuclear division is a general term, basically the dividing of the nucleus. It can either be my mitosis or meiosis (reduction division)

tx and sorry for the weird qn, i am just gettin messed up and panicked

 

[Soldier313]

Hey guys quick question, what are the relative bond strengths ?
like hydrogen , ionic, disulphide bonds and hydrophobic, whats the most to least? and how do you break each one? THANK YOU ! <3

i believe it's disulphide, ionic, hydrophobic then hydrogen , confirmed by confused123

 

[geek101]

tx and sorry for the weird qn, i am just gettin messed up and panicked

no problem, and just relax, hope there are alot ov repeated questions panicking is not gonna help sista! and pray! lots of good luck

 

[Soldier313]

no problem, and just relax, hope there are alot ov repeated questions panicking is not gonna help sista! and pray! lots of good luck

thanx so much for yr encouragement.... and yea am always praying