Biology Paper 1

[altox876]

which qstn ur talking about?

Vasodilation Shivering Sweating

 

[altox876]

i
it was cross tick tick

Read my other post where I linked some info. It suggests that answer should have been cross tick cross

 

[danial 234]

Read my other post where I linked some info. It suggests that answer should have been cross tick cross

do you remember the exact ques wording.

 

[thementor]

1) i think they pointed the spaces between guard cells (stomata)
2) evaporation was not mentioned, water loss from the leaf was mentioned
3) CO2 enters through stomata

dude....i have an eidetic memory...damn it was mentioned "most evaporation" wat the helll...cant u read?

 

[thementor]

I'm pretty sure it said transpiration :/ cause when I read that word, I automatically thought loss of water & hence stomata

IT SAID: FROM WHICH PART DOES MOST EVAPORATION OF WATER TAKE PLACE DURING TRANSPIRATION

 

[danial 234]

dude....i have an eidetic memory...damn it was mentioned "most evaporation" wat the helll...cant u read?

i ticked on the cell wall of spongy mesophyll. would it be correct

 

[altox876]

do you remember the exact ques wording.

From what i remember, the question was that the air temperature is greater than core body temperature. Which of the following can increase heat loss from body.

 

[thementor]

if mesophyll is correct i got 39/40

i don't think so logically, most of the water loss would be from the air passage leading outside without any restriction to overcome cells

dude evaporation of water occurs at the surface of the mesophyll cell...and loss of water occurs at the stomata...dont u people read books carefully...wat is wrong with the world????????????

 

[thementor]

I remember evaporation being mentioned. I also marked mesophyll as the answer

Yes it was mentioned and mesophyll was the answer....

 

[altox876]

i ticked on the cell wall of spongy mesophyll. would it be correct

Yes, it is the right answer.

 

[thementor]

i don't think so logically, most of the water loss would be from the air passage leading outside without any restriction to overcome cells

please do not apply logic overhere..and use widely accepted facts..
exact words from wikipedia
Water moves from the xylem into the mesophyll cells, evaporates from the mesophyll cells' surfaces and leaves the plant by diffusion through the stomata.

 

[danial 234]

From what i remember, the question was that the air temperature is greater than core body temperature. Which of the following can increase heat loss from body.

heat loss can be reduced by both methods though at a smaller degree by vasodilation.

 

[thementor]

if mesophyll is correct i got 39/40

38/40 for me...made two mistakes.

 

[altox876]

heat loss can be reduced by both methods though at a smaller degree by vasodilation.

Yes, but CIE mentioned air temperature instead of body temperature. There might be a reason for that.

 

[thementor]

i ticked on the cell wall of spongy mesophyll. would it be correct

yes it is absolutely correct

 

[danial 234]

Yes, but CIE mentioned air temperature instead of body temperature. There might be a reason for that.

rising of air temp is just like rising of body surface temp. and CIE always mentions a thing which increases the ambiguity in question just like in islamiat this year

 

[thementor]

Yes, but CIE mentioned air temperature instead of body temperature. There might be a reason for that.

It dosent matter...if air temperature is higher, thermoreceptors will detect this and transmit impulses to hypothalamus and set the negative feedback process into action...Confirmed..by the following source
BBC Bitesize.(England's Revision Source for GCSE exams)

 

[altox876]

rising of air temp is just like rising of body surface temp. and CIE always mentions a thing which increases the ambiguity in question just like in islamiat this year

In the question it was mentioned that the air temperature was greater than core body temp. Core is higher than surface temp. If the outside temperature is higher, heat exchange through skin by convection which is the main process can't occur as the air is warmer than the skin.

 

[thementor]

rising of air temp is just like rising of body surface temp. and CIE always mentions a thing which increases the ambiguity in question just like in islamiat this year

exactly

 

[danial 234]

In the question it was mentioned that the air temperature was greater than core body temp. Core is higher than surface temp. If the outside temperature is higher, heat exchange through skin by convection which is the main process can't occur as the air is warmer than the skin.

how can core be higher than suface temp in hot surroundings