• We need your support!

    We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
    Click here to Donate Now (View Announcement)

How was Biology Paper 42

How was Bio P42


  • Total voters
    71
Messages
114
Reaction score
36
Points
38
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....
at 30 the rate of photosythesis was at maxmuim if enzymes denatures then it should get to zero :|
 
Messages
115
Reaction score
42
Points
38
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.
I wrote almost same.but dot you think its less fr total 15 marks?.
 
Messages
114
Reaction score
36
Points
38
thats what i mean but i missed the last part :|
anyway its better than dividing 125 by 700 ! :p
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% ?
 
Messages
114
Reaction score
36
Points
38
yeah i had a doubt.....i wrote enyzymes denature as temperature increases above 30 degrees thus decreasing the rate
i dont remember the question but i guess t was asking ahy its at maximum at 30
so i wrote its an ezyme controlled reaction
enzyme K.e is high at thiss tempeture so enzyme activity is high .... bla bla bla
 
Messages
66
Reaction score
17
Points
18
Guys can I get the answer for the adaptations of the glomerular capillaries and podocytes for ultrafiltration??
 
Messages
489
Reaction score
3,658
Points
253
Glomerular capillaries r made up of endothelial cells nd have large gaps allowin most of it to pass through and fr podocytes they r finger like projectors made up of epithelial cell nd so help in filtering nd blah blah blah
Guys can I get the answer for the adaptations of the glomerular capillaries and podocytes for ultrafiltration??
 
Messages
11
Reaction score
5
Points
13
Guys can I get the answer for the adaptations of the glomerular capillaries and podocytes for ultrafiltration??

For glomerular capillaries, i wrote about the high pressure created by difference in diameter of afferent and efferent, causing the filtrate to be passed through basement membrane

And for podocytes from about finger like projections, increase surface area, more diffusion
 
Messages
313
Reaction score
165
Points
53
No, each point scores 1 mark for every question, so 15 total points = 15 total marks

capillaries had thin walls and large spaces in walls
podocytes were finger like projections which did stuff i've forgotten now :p

time lapse was helpful because it allowed best embryo to be selected, and disadvantage was even though 93% accurate, still had chance of failure, which could cause distress.
 
Messages
115
Reaction score
42
Points
38
What was that we have to label in that PCT or DCT it was i guess cant remember
 
Messages
64
Reaction score
25
Points
8
What was the answer for that Na/K pump question?
Why would the mRNA reduce in number and the previous part where they asked why the cells would survive if ion channels were closed?
 
Messages
64
Reaction score
25
Points
8
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....

I wrote that firstly the enzyme(Rubisco) will start losing the tertiary structure and get almost denatured at 50 C so Calvin cycle would reduce.
Secondly, due to high temperature, stomata closes to prevent transpiration and CO2 cannot enter,again reducing CO2 fixation.:)
 
Messages
129
Reaction score
39
Points
38
For glomerular capillaries, i wrote about the high pressure created by difference in diameter of afferent and efferent, causing the filtrate to be passed through basement membrane

And for podocytes from about finger like projections, increase surface area, more diffusion


same here :) what did u write for the question (which light dependent stage oxygen is produced) i wrote non cyclic - photolysis and the photosystem was type 2 right ?? and the question under it , i wrote because some oxygen is used in respiration
 
Top