AS Biology P1 MCQs Preparation Thread

[sarahnafea]

aoa wr wb

need help with this plz

jazakAllah

View attachment 12859

do we need photosynthesis for growth? yes we do because it produces glucose......looking at the other items in the table, is photosynthesis one of other life processes? yup. and finally...what do plants use to respire? oxygen...and what does oxygen do? break down glucose to release CO2...and where does this glucose come from? PHOTOSYNTHESIS! voila

 

[Soldier313]

aoa

these 2 questions plz...
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part 1
A - thats not true eg look at bacteria 5, week 4 and 5 is same
C - the antibiotic cnt be used for all, look at bacteria 5 again, all the x=zones are greater than 13
D - u cant know this, it may happen in the future
hence by elimination B is the answer

 

[sarahnafea]

for question 40, cell surface area is in the dictionary of the examiner another word for CELL MEMBRANE. cell membrane has hormone receptors. again, another word for cell volume is CYTOPLASM. in the cytoplasm all metabolic reactions take place, for example cellular respiration which produces CO2.

aoa

these 2 questions plz...
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[Nibz]

aoa

these 2 questions plz...
View attachment 12862

Q39. The question clearly states that "Zones of less 13 mm show the presence of resistant bacteria.
1 and 5 have more than 13 mm diameter after 5 weeks. The other 3 have less than that.
So 2, 3 and 4 are the types of bacteria that show resistance.

 

[The King XII]

If it's not too late does anybody understand the relationship between the girth (circumference) of a tree trunk and the cohesion-tension theory? It seems to be a recent favorite amongst the examiners. Thanks

Well think of it like this ehm ehm at night transpiration decrease right so the pressure at the leaf would increase right so what you're doing exactly is that you are reducing the pressure difference, its like a straw right you suck on a straw on top the diameter is reduced you stop sucking or you suck slowly the diameter rarely decreases so back to plants the xylem pressure on top is increased at night due to lack of transpiration, you could say that the pressure on top is canceling pressure at the bottom its like an equlibrium but pressure wise, no pressure diffrence would obviously show no change in the diameter.

 

[Soldier313]

helpppp

 

[Nibz]

helppppView attachment 12875

Pressure potential always has a positive value. So X is for pressure potential.
Solute potential always has a negative value. That's shown by curve Z.
Y is left. That has to be for water potential.

 

[sarahnafea]

Well think of it like this ehm ehm at night transpiration decrease right so the pressure at the leaf would increase right so what you're doing exactly is that you are reducing the pressure difference, its like a straw right you suck on a straw on top the diameter is reduced you stop sucking or you suck slowly the diameter rarely decreases so back to plants the xylem pressure on top is increased at night due to lack of transpiration, you could say that the pressure on top is canceling pressure at the bottom its like an equlibrium but pressure wise, no pressure diffrence would obviously show no change in the diameter.

first of all thanks. second, ur basically saying that if cohesion-tension forces increase as a result of increased transpiration during the day..girth DEcreases>\?

 

[DARK DRAGON]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w09_qp_12.pdf
Q19 Plz answer is D

PLZ anyone

 

[XPFMember]

AsSalamoAlaikum Wr Wb!

Is there anyone giving first variant? I mean...tomorrow...if i get doubts, will there be anyone to clear them?

 

[sarahnafea]

PLZ anyone

you cans split diploid into haploid, yes? yes. The question is...can you splid haploid any further? Absolutely not! The only type of division undergone by a haploid organism is mitosis/ asexual reproduction.

 

[Soldier313]

Pressure potential always has a positive value. So X is for pressure potential.
Solute potential always has a negative value. That's shown by curve Z.
Y is left. That has to be for water potential.

y cant u say that Y is solute p and Z is water p ?

 

[Nibz]

y cant u say that Y is solute p and Z is water p ?

Common sense.
Y is almost touching the x-axis. Z is never gonna meet the x-axis anytime soon.

 

[Soldier313]

A tree carries out photosynthesis and provides organic compounds for other organisms in a forest. It takes carbon dioxide from and returns oxygen to the atmosphere. It takes water from the soil into its roots and its leaves lose water to the atmosphere. Many other organisms live in the tree.
Which term applies to the description of the tree?
A ecosystem
B habitat
C niche
Dtrophic level

 

[XPFMember]

aoa wr wb
first time....did i ever have the feeling...there's been help for bio

Anyway....thanks a lot to alll....!

Ya Allah...plz grant success in both worlds to all those who helped...and those who couldn't ....Aameen...YaAllah guide us all..to Jannah...and make us among the muttaqeen and saliheen...aameen!

wassalamoalaikum warehmatullahi wabarakatuh!

 

[The King XII]

helppppView attachment 12875

Well the answer is D correct me if I'm wrong, okay explanation "W.p of cell = Pressure.p + solute potential".

okay so in the middle we have incipient plasmolysis you have to check the images for this, at this point, pressure potential is zero and both the water potential and solute potential are negative always (remember that solute potential can never be positive alright) so follow the equation at incipient plasmolysis water potential of cell = solute potential. lets go to turgid the water potential is zero why know since pressure potential can become more positive (it can exceed zero) WHEN THE CELL IS TURGID, and like i said the solute potential is always negative so "W.P of cell = 3.5-3.5" which is zero so "-" is for the solute potential and "+" is for the pressure potential and that only occurs when turgid okay, so W.p of cell is 0.

 

[XPFMember]

A tree carries out photosynthesis and provides organic compounds for other organisms in a forest. It takes carbon dioxide from and returns oxygen to the atmosphere. It takes water from the soil into its roots and its leaves lose water to the atmosphere. Many other organisms live in the tree.
Which term applies to the description of the tree?
A ecosystem
B habitat
C niche
Dtrophic level

niche...cuz it describes the role of a tree in its environment...

 

[sarahnafea]

y cant u say that Y is solute p and Z is water p ?

Solute Potential is obviously more negative as it contains solutes. Water potential is WATER potential. Lol...which means less/no solutes...which means less negativeor closer to zero!

 

[Nibz]

A tree carries out photosynthesis and provides organic compounds for other organisms in a forest. It takes carbon dioxide from and returns oxygen to the atmosphere. It takes water from the soil into its roots and its leaves lose water to the atmosphere. Many other organisms live in the tree.
Which term applies to the description of the tree?
A ecosystem
B habitat
C niche
Dtrophic level

Niche.

 

[geek101]

helppppView attachment 12875

remember this... Ψ = Ψs + Ψp
and the pressure potential is always positive so X is pressure potential
now looking at the equation we know water potential is always negative, but solute potential has to be even more negative, cuz the pressure potential will be added to it, therefore Z is solute potential and Y is water potential