How was Biology Paper 42

[Jinkglex]

if u read the statment well u will get it
multiplying the percentage by 125 means that
58.3 per cent of blood was plasma
so 58.3 percent of the 125 is 72.9

No i got that, but what i dont understand is why would you make 58.3 percent of the 125? considering the examiner has already told us 125 cm3 has gotten through? and 1200 was the volume occupied by plasma fluid and also OTHER compounds e.g protiens which cant get through basement membrane

 

[mariyam95]

think about it....does the whole of the blood pass into the renal capsule??....only the plasma of the blood passes through rite???....no red or white blood cells.....there was 750cm3 of plasma.....and 125cm3 passed into the renal capsule....so percentage is 125/700 *100

so what about the glucose and other substance dissolved in the blood ??

u can do it this way also
700-----1200
x----125

125x700\1200 = 72.9

 

[Jinkglex]

for section B i chose 9, here are my points:

A) prokaryotic cell so smaller then eukaryotic cell, no nucleus, naked DNA, looped DNA, small circular strands of DNA called plasmids, cell wall made of peptidoglycans, may be protected by capsule, do not have double membraned organelles such as golgi body, and one more i think but i cant remember it

B) process called bioleeching, use thermophilic bacteria, bacteria must be able to cope with acidic conditions as H2SO4 produced, used on low quality ores where conventional is too expensive, bacteria are reused, family of bacteria called ferroxidans.

 

[terry jefferson]

so what about the glucose and other substance dissolved in the blood ??

u can do it this way also
700-----1200
x----125

125x700\1200 = 72.9

glucose and other substances and water make up the plasma.....you dont use 1200 at all....thats just the total volume of blood....they asked bout the percentage volume of plasma passing through....

 

[mariyam95]

glucose and other substances and water make up the plasma.....you dont use 1200 at all....thats just the total volume of blood....they asked bout the percentage volume of plasma passing through....

lets wait for the mark scheme

 

[Jinkglex]

electrophoresis -> cut up DNA strands with restriction enzymes which cleave close to known VNTR regions, place on pure agarose gel, pass D.C current, they move according to size, use absorbent paper to pick them up, and replicate with radioactive nucleotides.

we will know if genes are same if they are on same position after electrophoresis results

antibiotic resistors not used as they form hazard and if organism escapes will be much harder to kill using antibiotics.

 

[Jinkglex]

Guys stop being stuck on just one question

 

[mariyam95]

what about the inhibition question ?

 

[Jinkglex]

competitive inhibition considering the concentration of warfarin had to be varied meaning the vitamin K competes with it at different concentrations.

 

[terry jefferson]

genetic diagram question......gametes W-resistant w-susceptible
resistant male-Ww resistant female-Ww
offspring genotypes- WW, Ww, Ww, ww
offspring phenotypes-Resistant Resistant Resistant Susceptible

the answer to the next part of the same question asking why heterozygotes wont survive.......this is because there is not enough supply of vitamin K in the environment for all to feed....

 

[littlecloud11]

so what about the glucose and other substance dissolved in the blood ??

u can do it this way also
700-----1200
x----125

125x700\1200 = 72.9

The question asked what percentage of the plasma was filtered right?

By your method,
12oo cm^3 blood -----> 700 cm^3 plasma
so 125 cm^3 blood -----> 72.9 cm^3 plasma.

The question wanted what PERCENTAGE of the plasma was filtered not the volume of plasma in 125 cm^3, so shouldn't it have been 72.9/700* 100 = 10.4% ?

 

[tasmiah2310]

Got confused in the inhibition question, wrote competitive but don't think could explain why

and the pupfish question when lake reforms, wrote about survival of the fittest.. but mentioned disruptive selection

Hope the gt for an A doesnt get to 80 given the relative easiness of the paper compared to other years
Paper wasn't long either.

 

[tasmiah2310]

And also the disadvantage of time lapse microscopy method for the embryo -_-

 

[terry jefferson]

For Q1 part ii).....the one where they ask us to explain the shape of the graph after 30 degrees celsius.....i wrote that the plant will have to be a C3 plant and so the enzymes denature above 30 degrees thus decreasing rate of photosynthesis....

 

[terry jefferson]

And also the disadvantage of time lapse microscopy method for the embryo -_-

I wrote that there might be genetic disorders present so that wont be detectable....dont know whether its right..

 

[Ahmad Zaeem]

My Section B went Amazing !!!......just got lucky !!!!!! i guess ..

 

[littlecloud11]

And also the disadvantage of time lapse microscopy method for the embryo -_-

I wrote predicts the success of survival following implantation but doesn't predict the chances of successful implantation. And for then second disadvantage I wrote that the remaining embryos have to be discarded and how that presents as a ethical issue.

 

[fathimaash]

The question asked what percentage of the plasma was filtered right?

By your method,
12oo cm^3 blood -----> 700 cm^3 plasma
so 125 cm^3 blood -----> 72.9 cm^3 plasma.

The question wanted what PERCENTAGE of the plasma was filtered not the volume of plasma in 125 cm^3, so shouldn't it have been 72.9/700* 100 = 10.4% ?

Exactly I did the same.

 

[terry jefferson]

what was the answer to the question where they asked us how the GLOMERULAR CAPPLILARIES and PODOCYTES were adapted for ultrafiltration.....got stuck on that one...

 

[mariyam95]

Exactly I did the same.

daaaaammmnnn i missed the last part :S :S :S :S
any way i may get 1 mark