bio query

[adnanj]

what is the difference between stomata and guard cell??

 

[SAUD ASLAM]

Guard cell controls the opening oof stomata(it is hole between the two guard cell)

 

[Silent Hunter]

ya.........there are two guard cell and the hole between them is stomata

 

[adnanj]

how do we find magnification in bio atp paper???

 

[falcon678]

well its like:
measurement of diagram X 100
measurement of photograph

 

[Silent Hunter]

well it may not be 100 allways
it can be X1000 OR 950 ETC ETC
but major part remains the same which is
measurement of diagram /measurement of photo given

 

[adnanj]

thx everyone

 

[Silent Hunter]

no problem

 

[adnanj]

in reflex action, does brain receive info?

 

[CaptainDanger]

in reflex action, does brain receive info?

No... Spinal cord does the job.... Though brain does receive the info after the action takes place... But reflex action is all controlled by spinal cord....

 

[adnanj]

plz explain mcq 22 of winter 2007

http://www.xtremepapers.me/CIE/index.ph ... 7_qp_1.pdf

 

[abcde]

It's simple. The answer would be C. For the person to feel the pin prick, the nerve impulse must be able to travel to the brain. However, he can still move his leg as the sensory and motor neurones are perfectly functional (no anaesthetic block on them).
Hope this helped.

 

[CaptainDanger]

plz explain mcq 22 of winter 2007

http://www.xtremepapers.me/CIE/index.ph ... 7_qp_1.pdf

ER says this:
The man can move his leg in response to a pinprick. This is a reflex, so blocks X and Y must not in place. He cannot feel the pinprick, so the block must be at Z.


Got it?

 

[VelaneDeBeaute]

in reflex action, does brain receive info?

Wat i know is that the information is sent to the brain but b4 it knows wats happened the action is dun..!!

 

[CaptainDanger]

Ummm... Thanks for adding that....

 

[adnanj]

i am not getting it.. shouldn't it be at X??? because it is said that the person is not able to feel the pain but can respond.. so it should be at X.. if it would be at Z, how would he respond???

 

[abcde]

AOA!

i am not getting it.. shouldn't it be at X??? because it is said that the person is not able to feel the pain but can respond.. so it should be at X.. if it would be at Z, how would he respond???

First of all, one should know that the ability to respond to a pinprick is an example of a reflex action, which is controlled by the spinal cord. If the anaesthetic block is at X, the person would not be able respond since a nerve impulse cannot be transmitted to the spinal cord (X is clearly on the sensory neurone). If it is at Y, again the person would not be able to respond as a nerve impulse would not be able to travel to the effector (Y is on the motor neurone). However, if it at Z, there is no hindrance in the reflex arc at all, that is, the nerve impulse can travel from the receptor to the sensory neurone to the spinal cord to the motor neurone and then finally to the receptor, enabling the person to exhibit a response. Secondly a person can only feel a pinprick if a nerve impulse is transmitted to the brain. If the block is at Z, no nerve impulse reaches the brain, thus the person does not feel anything.
Therefore, the person has an anaesthetic block at Z.
Hope this made you understand.

 

[adnanj]

walekumassalam.. thanks alot abcde... explained very well.. cleared to me now..

 

[abcde]

You're welcome