Biology Paper 1

[anamta]

What did you do in the question of air temperature is greater than body temperature?

do u remember the options?

 

[altox876]

do u remember the options?

First two were wrong because they had shivering ticked. C was shivering cross sweating tick vasodilation tick. D was shivering cross sweating tick and vasodilation cross.

 

[Aly Emran]

no it can't be becteria, they asked for a group of cells but becteria is unicellular organism so i guess it was C( it can be fungus and it can't be a becteria)

bacteria r uni and multi both cellular

 

[anamta]

First two were wrong because they had shivering ticked. C was shivering cross sweating tick vasodilation tick. D was shivering cross sweating tick and vasodilation cross.

yay!! so mines correct i did C

 

[Talha Irfan]

bacteria r uni and multi both cellular

they are originally uni, but they can said to be multi as some of them have more than 100 nucleic acids

 

[anamta]

bacteria r uni and multi both cellular

NO... i read it in the Cambridge biology revision guide :/ anyways i don't know may be i got it wrong

 

[Talha Irfan]

from this i got 38/40

perfect

 

[Talha Irfan]

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

 

[Talha Irfan]

cox mesophyll is covered with water film and it leaves there when they r heated into the air spaces as a result more water potential inside the plant and water vapours move out by difussion though stomata

yes, but main cause is stomatal openings,

 

[Talha Irfan]

stomal opening causes water to move out by diffusion! they said where MOST evapouration occured. i guess they did not highlighted stoma but they highlighted guard cell but most evapouration occurs from spongy cells while stoma is not responsible for evapouration. its only role is closing and opening plus what if they said where most CO2 dissolves for at daytime? would u say stoma or film covering mesophyl?

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

 

[Talha Irfan]

1) if even stoma wa mention it seemed wrong to me
2) i remember the question well cox i thought a lot over it it said " Where does Most Evapouration occured in a leaf" the keywords i remember were most and evapouration rest of the question idk
3) CO2 enter though stoma but doess not dissolve over there it dissolves in water and then moves in the cell

that was a similar question to others which came in past papers, i think they just changed the wordings, like they did with lactose one, that mcq was same but wording was different

 

[Talha Irfan]

1) if even stoma wa mention it seemed wrong to me
2) i remember the question well cox i thought a lot over it it said " Where does Most Evapouration occured in a leaf" the keywords i remember were most and evapouration rest of the question idk
3) CO2 enter though stoma but doess not dissolve over there it dissolves in water and then moves in the cell

just check D2000 p1 q14

 

[Talha Irfan]

ahan last year question they said where does water leaves the leaf this time it was evapouration. thats the point they want to assess students kay past ppr kay rattay lagaiyn haan ya unko samjha bhi ha!

no, the one i quoted mentions water loss (evaporation)

 

[Talha Irfan]

can u write the question cox i dont have that old past pprs

it mentions water loss, and answer is stomata

 

[Talha Irfan]

evaporation means changing of water into water vapours not water loss
this souce mention water evaporates through mesophyll cells
http://wiki.answers.com/Q/What_is_t...eing_loosely_arranged_instead_of_being_closed

are u 100% sure "evaporation" was mentioned

 

[Talha Irfan]

i am 1000% sure am i mad to mark D if evaporation was not mention they even stated MOST toooo koi baat nahi agar mera ghalat ho jata ha to 38/40 isnt bad

same here agar ghalat hota hai hai tu 38/40 Insha Allah

 

[Talha Irfan]

but i am at risk cox in p6 i might get 37 in p2 67 and p1 38 and its 88 or 89 %

Don't worry, threshold will save you

 

[altox876]

are u 100% sure "evaporation" was mentioned

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

 

[Snowysangel]

are u 100% sure "evaporation" was mentioned

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

 

[altox876]

http://coachsci.sdsu.edu/csa/vol36/rushall1.htm
During exercise the body produces a great deal of heat. In extreme circumstances this can elevate its core temperature from 37° C to beyond 40° C. When the surrounding air is cool heat can be lost from the body by the process of radiation (transfer of heat by electromagnetic waves), convection (by air movement), conduction (by contact), and evaporation (by sweating). As the surrounding temperature increases it becomes more and more difficult to lose heat by radiation, convection, and conduction. Hence, the predominant source of heat loss in warm to hot conditions is from the evaporation of sweat on the skin surface.

According to this the answer of question 20 homeostasis should have been D. What are everyone's thoughts?