guys biology paper 2 is on 29 of may ...i need some help

[Amy farvin]

abdullah ash
thanx for ur guess about enzyme coz that was my guess too..
lionkill3r
thanx for ur guess too.

 

[eyamwir]

for sure ecology, immunity and infectious disease will come out.

 

[Amy farvin]

oh thanx for sharing it.. im also sure about diseases and immunity.. it will cum as 1 question... ecology wat type of question do u think will cum?? nitrogen cycle???

 

[Amy farvin]

and have any bio p5?

i got notes for p5 from xtreme papers see if its gud.. but those are the only notes i have till now for p5 and its really good...
donno how its for u...

 

[Amy farvin]

i got some tips from an other thread too.. its really good..

 

[sarahnafea]

I have a question!
In the book it says that in Emphysema the blood vessels in the lungs become resistant to blood flow so increasing the blood pressure in the pulmomary artery and consequently enlarging the right side of the heart. Why exactly does Emphysema cause b.v.s in the lungs to become resistant to blood flow? Would really appreciate an answer

 

[KurayamiKimmi]

I have a question!
In the book it says that in Emphysema the blood vessels in the lungs become resistant to blood flow so increasing the blood pressure in the pulmomary artery and consequently enlarging the right side of the heart. Why exactly does Emphysema cause b.v.s in the lungs to become resistant to blood flow? Would really appreciate an answer

i tried findin that in my book and it wasnt there =O
so heres what wiki says
As the alveoli continue to break down, hyperventilation is unable to compensate for the progressively shrinking surface area, and the body is not able to maintain high enough oxygen levels in the blood. The body's last resort is vasoconstricting appropriate vessels. This leads to pulmonary hypertension, which places increased strain on the right side of the heart, the side responsible for pumping deoxygenated blood to the lungs. The heart muscle thickens in order to pump more blood
that should answer your question ^^

 

[sarahnafea]

i tried findin that in my book and it wasnt there =O
so heres what wiki says
As the alveoli continue to break down, hyperventilation is unable to compensate for the progressively shrinking surface area, and the body is not able to maintain high enough oxygen levels in the blood. The body's last resort is vasoconstricting appropriate vessels. This leads to pulmonary hypertension, which places increased strain on the right side of the heart, the side responsible for pumping deoxygenated blood to the lungs. The heart muscle thickens in order to pump more blood
that should answer your question ^^

THANK U so much god bless you!

 

[eyamwir]

oh thanx for sharing it.. im also sure about diseases and immunity.. it will cum as 1 question... ecology wat type of question do u think will cum?? nitrogen cycle???

not so sure about what kind of question maybe nitrogen cycle

 

[eyamwir]

can anyone explain to me how assimilates move through phloem tissue in a simple and effective way? i'm a bit confused with the textbook diagram and mary jones revision guide book.

 

[littlecloud11]

can anyone explain to me how assimilates move through phloem tissue in a simple and effective way? i'm a bit confused with the textbook diagram and mary jones revision guide book.

Ok, here it goes-

• After the sucrose has moved into the companion cell it enter the sieve tube cell through the plasmodesmata by diffusion down the conc. gradient.
• Sucrose lowers the osmotic potential in the sieve tube cell, so water enter the cell by osmosis from neighboring cells.
• Water increases the hydrostatic pressure in the sieve tube cell
• At the sink, sucrose is removed and is converted into glucose and used up in respiration. or else stored as starch.
• The water also moves out, following the sucrose and therefore the hydrostatic pressure is lower in the sieve tube at the sink.
• The water flows from a region of high hydrostatic pressure at the source to a region of low hydrostatic pressure at the sink carrying the sucrose along with it.
• The sucrose is thus transported by mass flow.

Hope this helps!

 

[eyamwir]

Ok, here it goes-

• After the sucrose has moved into the companion cell it enter the sieve tube cell through the plasmodesmata by diffusion down the conc. gradient.
• Sucrose lowers the osmotic potential in the sieve tube cell, so water enter the cell by osmosis from neighboring cells.
• Water increases the hydrostatic pressure in the sieve tube cell
• At the sink, sucrose is removed and is converted into glucose and used up in respiration. or else stored as starch.
• The water also moves out, following the sucrose and therefore the hydrostatic pressure is lower in the sieve tube at the sink.
• The water flows from a region of high hydrostatic pressure at the source to a region of low hydrostatic pressure at the sink carrying the sucrose along with it.
• The sucrose is thus transported by mass flow.

Hope this helps!

thank you it does help a whole lot and even better than the textbooks!

 

[eyamwir]

describe and explain how CO2 and H+ play a role in the unloading of oxygen from haemoglobin. can anyone explain this? marking scheme answer does not help me.

 

[littlecloud11]

thank you it does help a whole lot and even better than the textbooks!

Anytime.

 

[littlecloud11]

describe and explain how CO2 and H+ play a role in the unloading of oxygen from haemoglobin. can anyone explain this? marking scheme answer does not help me.

When the partial pressure of CO2 is high it diffuses into RBC where it reacts with H2O to form carbonic acid. This reaction is catalysed by carbonic anhydrase. The carbonic acid then dissociates to form H+ and HCO3-. The hydrogen carbonate ion diffuses out but the H+ ion reacts with the haemoglobin to form haemoglobulinic acid. The H+ is replacing the O2 combined with haemoglobin when it reacts with it, as a result the oxygen is released by hemoglobin.

 

[eyamwir]

Anytime.

do you mind answering my latest post? i'm kind of yeah confused right now about that.

 

[littlecloud11]

do you mind answering my latest post? i'm kind of yeah confused right now about that.

Already did.

 

[eyamwir]

what about explain how heart action is initiated and controlled

 

[eyamwir]

and what are the things we should learn in core G?
transport in plant :
xerophyte,
transport of water in xylem,
transport of sucrose in phloem
role of companion cell
transpiration

transport in mammal :
arteries, vein capillaries
how co2 is transported
bohr shift + haemoglobin
cardiac cycle
structure of heart

is that it? just to make sure...

 

[eyamwir]

and what is a mass flow? sorry i'm asking too much questions here :s i'm pretty nervous about my exam which is tomorrow.