AS Biology P1 MCQs Preparation Thread

[Ikram Khaliq]

If the wavelength of light is 600 nm, then two membranes 300 nm apart will be visible as two
distinct membranes.
is this true or false? explanation?

 

[SalmaXXXX]

If the wavelength of light is 600 nm, then two membranes 300 nm apart will be visible as two
distinct membranes.
is this true or false? explanation?

False, It's not about the distance between the two membranes. With a resolution of 300 nm, you won't be able to differentiate the membarem ( 7nm) from its surrounding medium.

 

[1357911]

If the wavelength of light is 600 nm, then two membranes 300 nm apart will be visible as two
distinct membranes.
is this true or false? explanation?

can u plz tell me which year is this question from

 

[1357911]

False, It's not about the distance between the two membranes. With a resolution of 300 nm, you won't be able to differentiate the membarem ( 7nm) from its surrounding medium.

can u plz explain. i still didnt understand

 

[SalmaXXXX]

o/n 2012 varient 11 q-33,36,and 40......... SOMEBODY PLZZ HELP

40 )
All you have to do is to find the GGP of the tertiary consumer ( fourth trophic level) which is not shown here. First calculate the GGP for 2nd TL 23000- 8000 = 15000. Then calculate GGP for 3rd TL 15000 - 10500 = 4500. Then calculate GPP for 4rth TL 4500 - 4200 = 300. Now calculate the percentage 300/23000 x 100 = 1.3. Hope that was helpful

 

[HubbaBubba]

o/n 2012 varient 11 q-33,36,and 40......... SOMEBODY PLZZ HELP

q33 - It has to be D, because the amount of smokers at the start of 1950 is 80%. That means if 60% decreased, then 32% of smokers should remain which according to the graph is wrong. Graph shows that it's around 35-37%. The fact that they said 'approximately' is a key word in this statement.

q36 - Definitely A. Lymphocytes are produced in bone marrow, so it makes sense that they get a bone marrow transplant. Antibiotics, and vaccinations will not work, and transfusion of antibodies is a short term method.

q40 - We begin with 23000. You need to find out how much energy is passed on to the fourth trophic level (tertiary consumers). 23000 - 8000 = 15000 passed to the second trophic level (primary consumers). 15000 - 10500 = 4500 is passed onto the third trophic level (secondary consumers). 4500 - 4200 = 300 passed to the tertiary consumers. 300/23000 * 100 = 1.3 A is the answer

 

[Ikram Khaliq]

can u plz tell me which year is this question from

this is O/N12 p11

 

[1357911]

40 )
All you have to do is to find the GGP of the tertiary consumer ( fourth trophic level) which is not shown here. First calculate the GGP for 2nd TL 23000- 8000 = 15000. Then calculate GGP for 3rd TL 15000 - 10500 = 4500. Then calculate GPP for 4rth TL 4500 - 4200 = 300. Now calculate the percentage 300/23000 x 100 = 1.3. Hope that was helpful

thanks

 

[SalmaXXXX]

can u plz explain. i still didnt understand

Resolution means the ability to distinguish between two different points. With a resolution less than 7 nm, you won't be able to differentiate the membrane from its surroundings, you won't see it.

 

[1357911]

Resolution means the ability to distinguish between two different points. With a resolution less than 7 nm, you won't be able to differentiate the membrane from its surroundings, you won't see it.

Oh got it. Thanks a lot

 

[1357911]

o/n 2011 varient 11 q-5,6,8 anyone????

 

[daredevil]

o/n 2011 varient 11 q-5,6,8 anyone????

5) 40 divisions of the eyepiece grat = 0.1 mm (from the stage micrometer)
chloroplast = 5 divisions of the eyepiece grat.
5 divisions of eyepiece graticule = (0.5/40)


6) prokaryotes do not have a nuclear memberane as they do not have a defined nucleus. so the prophase of division of prokaryotes is much shorter without the need to dissolve the nuclear memberane to start the division process.

8) when the two monosacchrides combine they have to realease a water molecule too. so add all the elements e.g. of maltose : -
C12H24O12 --> subtract a H2O molecule from it and u have --> C12H22O11

 

[1357911]

5) 40 divisions of the eyepiece grat = 0.1 mm (from the stage micrometer)
chloroplast = 5 divisions of the eyepiece grat.
5 divisions of eyepiece graticule = (0.5/40)


6) prokaryotes do not have a nuclear memberane as they do not have a defined nucleus. so the prophase of division of prokaryotes is much shorter without the need to dissolve the nuclear memberane to start the division process.

8) when the two monosacchrides combine they have to realease a water molecule too. so add all the elements e.g. of maltose : -
C12H24O12 --> subtract a H2O molecule from it and u have --> C12H22O11

in q-8 how do u know the formula of maltose?

 

[1357911]

Which molecule has its synthesis directly controlled by DNA?
A amylase
B cholesterol
C glycogen
D phospholipid

 

[daredevil]

in q-8 how do u know the formula of maltose?

umm firstly it is included in the syllabus so u should know it.
and secondly look 2 glucose molecules undergo condensation to make a maltose. add 2 glucose and u'll get C12H24O12 then subtract a water molecule from them and u'll be left with a maltose molecule i.e. C12H22O11

 

[daredevil]

Which molecule has its synthesis directly controlled by DNA?
A amylase
B cholesterol
C glycogen
D phospholipid

is the answer cholestrol?? it was just a guess btw -.-

 

[SalmaXXXX]

I

Which molecule has its synthesis directly controlled by DNA?
A amylase
B cholesterol
C glycogen
D phospholipid

I think it's amylase since it's an enzyme ( pure protein) and the DNA controls protein synthesis. From where did you get that question?

 

[sweetjinnah]

o/n 2011 qp 11:mcq 39 plzzz help..http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_w10_qp_11.pdf

 

[1357911]

I


I think it's amylase since it's an enzyme ( pure protein) and the DNA controls protein synthesis. From where did you get that question?

9700/11/O/N/11 yes its amylase. Thanks

 

[fishcook]

C is wrong cause with this resolution you can't even see the membrane. It's not about the distance between two membranes. Your eyes won't be able to distinguish it from the medium around it. You need a resolution of more than 7nm to see the cell membrane

But resolution= wavelength / 2. So the resolution of a 600nm wavelength should give a 300nm resolution. And since resolution is the ability to distinguish between 2 points then 2 membranes 300 nm apart should be seen as separate points..
Right?