A level Biology: Post your doubts here!

[♣♠ Magnanimous ♣♠]

Yeah same
But not 1
It will decrease the diffusion gradient for oxygen na?

D maybe or C

 

[manutd96]

yea the options are correct.. this is tricky..

 

[RoOkaYya G]

Yeah same
But not 1
It will decrease the diffusion gradient for oxygen na?

hmm yeah i guess so

 

[♣♠ Magnanimous ♣♠]

yea the options are correct.. this is tricky..

hmm yeah i guess so

dude recheck the opt coz it is all of these...
Asthma will obviously decrease the diffusion of oxygen, and as you said about that goblet cells it will increase secr of mucus. But I am not sure about 2.
So it should either be 1,3 or 3 only.

 

[manutd96]

dude recheck the opt coz it is all of these...
Asthma will obviously decrease the diffusion of oxygen, and as you said about that goblet cells it will increase secr of mucus. But I am not sure about 2.
So it should either be 1,3 or 3 only.

oops sorry typo!
A. 1,2
B. 1,3*
C. 2,3
D. 3

so do you think its B or D?

 

[RoOkaYya G]

dude recheck the opt coz it is all of these...
Asthma will obviously decrease the diffusion of oxygen, and as you said about that goblet cells it will increase secr of mucus. But I am not sure about 2.
So it should either be 1,3 or 3 only.

stop messin with my brain im done with bio xD i forgot bio since i pen down last paper

 

[♣♠ Magnanimous ♣♠]

oops sorry typo!
A. 1,2
B. 1,3*
C. 2,3
D. 3

so do you think its B or D?

As I said CHECK THE OPTIONS
It's 1,3

 

[♣♠ Magnanimous ♣♠]

stop messin with my brain im done with bio xD i forgot bio since i pen down last paper

I like to mess everyones brain by asking them silly doubts and going on asking doubts

 

[manutd96]

As I said CHECK THE OPTIONS
It's 1,3

ok thanks!

 

[♣♠ Magnanimous ♣♠]

ok thanks!

 

[Panda.lover :3]

asalam o alaikum i needed to know the variants for paper 4&5 biology 9700 according to zone 4

 

[Panda.lover :3]

please i need this info now

 

[♣♠ Magnanimous ♣♠]

asalam o alaikum i needed to know the variants for paper 4&5 biology 9700 according to zone 4

well I am in zone 4 so we give 34 22 12 42 52

 

[maryam fatima]

guys what do u expect the gt for bio paper 42, 2014?

 

[maryam fatima]

and paper 52 as well

 

[TimBluesWin]

guys what do u expect the gt for bio paper 42, 2014?

Around 58s....

and paper 52 as well

Should be 18-19s; it's hard...

 

[maryam fatima]

Around 58s....

Should be 18-19s; it's hard...

same estimate for p5 but i think paper 4 would be around 65...

 

[Wolfgangs]

Can someone explain "proportional dilution" for me? Or does anyone have notes for that dilution?

 

[RoOkaYya G]

Can someone explain "proportional dilution" for me? Or does anyone have notes for that dilution?

u mean simple dilution or serial dilution?

 

[Wolfgangs]

"
using proportional dilution, by adding a unit volume of a solution of a known concentration to a
solvent to obtain the required concentration, e.g. to dilute a stock solution by 5, 1 cm3 of the stock
solution is added to 4 cm3 of solvent. This gives a 1:5 dilution. To make a standard volume of a specific
concentration a formula V1C1 = V2C2 can be used. V1 is the volume of the stock solution, C1 the
concentration of the stock solution and V2 is the volume of the required solution, C2 is the concentration
of the required solution, e.g. a stock solution contains 100 mg cm–3 (C1) and need to make 10 cm3
(V2) of a solution with a concentration of 25 mg cm–3 (C2). The volume of stock solution needed is
V1 = 10 cm3 (V2) × 25 mg cm–3 (C2) / 100 mg cm–3 (C1). Cancelling units, V1 = 100 cm3 (V2) × 25 (C2) / 100
(C1) = 2.5 cm3"

I found this in our Biology syllabus. But I need more information about it.