AS Biology P1 MCQs Preparation Thread

[1357911]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w12_qp_12.pdf
12, 23, 33,34 and 39! pleeease explain

questions 33 and 34,Im a little confused. regarding quention 39 i think u know that nitrification is when the nitrites are changed to nitrates. so the answer is obviously C

 

[Alicee]

And no tertiary and quarternary structures do not contain peptide bonds

Im sorry but which orders are u talking about

ah! okay! got it thanks!

someone please explain dese!!!
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_w12_qp_12.pdf
33,34 and 39!

 

[Alicee]

12) A primary structure doesn't contain hydrostatic bonds so option A is out. A secondary structure doesn't contain ionic bond so B is out. A quatenary structure does contain hydrogen bond so D is out. B is the correct answer, by the type of bonds found, he means the types of bond which maintain that specific structure. The peptide bond doesn't maintain the tertiary structure.

23) None of B, C , D is supported by the information given. However, it's clear that Leu amino acid has more than one triplet genetic code that codes it so option A is correcr answer.

33) Deposition of fatty materials in arteries surely can result a heart failure. But he stated in arteries AND veins. Deposition in veins plays no role thus excluding 2. The other three are correct so option D is correct answer.

39) that's easy, nitrification takes place whether from ammonium to nitirites or from nitrites to nitrates so option C is corect.

thanks!

in 39 what is the process B?

 

[1357911]

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

 

[SalmaXXXX]

thanks!

in 39 what is the process B?

This is denitrification, changing nitrates to Nitrogen gas.

 

[1357911]

which disease is treated with drugs that have a similar molecular structure to DNA molecule?
A cholera
B HIV AIDS
C malaria
D tuberculosis

 

[SalmaXXXX]

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

In 33, if you took a look at option D, it states that the decrease is by 60% when in the graph, it barely passes the 45% ( from 80% to 35%).
In 36, since the T lymphocytes is produced from stem cells in the Bone marrow, then the problem lies there and it has to be transplanted. We don't need antibodies transfusion since they are broken down rapidly in the body neither do we need vaccination against all the diseases because even then cytokineses is not present and production of antibodies won't be activated.

In 40, i have explained that in an earlier post, just flip through them here

 

[SalmaXXXX]

which disease is treated with drugs that have a similar molecular structure to DNA molecule?
A cholera
B HIV AIDS
C malaria
D tuberculosis

HIV and the drug is called zidovudine.

 

[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