Physics, Chemistry and Biology: Post your doubts here!

[Ayesha Asif333]

The whole of the selective reabsorption process is confusing and it remained till the day of my exam when eventually I was told to watch this

U can start watching it from 5:12, the guy pretty much explains everything

 

[princess of cricket]

The whole of the selective reabsorption process is confusing and it remained till the day of my exam when eventually I was told to watch this

U can start watching it from 5:12, the guy pretty much explains everything

Thanx Ayesha Asif333 it really helped.
I have another question:
Describe four important processes that take place in the buccal cavity

 

[princess of cricket]

Yahoo answer says it's speech digestion chewing & salivation
But I want the correct and confirmed answer .

 

[Ayesha Asif333]

You're welcome
Yes,
The very first process will be chewing and grinding- the teeth will break the larger food molecules to smaller, digestible ones
The food is then mixed with the saliva, which lubricates it enzymes present in the saliva starts the chemical digestion
The tongue is there to mix and churn the food so that it takes the shape of a bolus..this bolus of food is then pushed back by the tongue into the oesophagus..this process is called swallowing
So we have 1)chewing/churning/grinding(mechanical digestion),2) salivation, 3)chemical digestion, 4) swallowing
Also, I would like to know what speech is...never heard of this term

 

[princess of cricket]

You're welcome
Yes,
The very first process will be chewing and grinding- the teeth will break the larger food molecules to smaller, digestible ones
The food is then mixed with the saliva, which lubricates it enzymes present in the saliva starts the chemical digestion
The tongue is there to mix and churn the food so that it takes the shape of a bolus..this bolus of food is then pushed back by the tongue into the oesophagus..this process is called swallowing
So we have 1)chewing/churning/grinding(mechanical digestion),2) salivation, 3)chemical digestion, 4) swallowing
Also, I would like to know what speech is...never heard of this term

Thanx

 

[sammi hamid]

 

[Emmris]

View attachment 62639

He answer is 46 s

 

[princess of cricket]

View attachment 62639

Answer is b

 

[studyingrobot457]

He answer is a

lol be careful, notice it is 0.05 s away from 60 so...
46.5-0.05
is equal to 46.0
So B is answer
Really you gonna waste marks this way on the real O-level exam

 

[Thought blocker]

He answer is a

it is b. lol noob

 

[Emmris]

lol be careful, notice it is 0.05 s away from 60 so...
46.5-0.05
is equal to 46.0
So B is answer
Really you gonna waste marks this way on the real O-level exam

I know the answer it's just typing mistake n I had 2 hurry up cuz I was using mobile data ....

 

[Emmris]

it is b. lol noob

 

[Thought blocker]

I know the answer it's just typing mistake n I had 2 hurry up cuz I was using mobile data ....

 

[Emmris]

O hav a doubt .... can a person doing dialysis get diseases transmitted by blood ( e.g : HIV ).....

 

[studyingrobot457]

O hav a doubt .... can a person doing dialysis get diseases transmitted by blood ( e.g : HIV ).....

How would that happen? Duh
dialysis machine is nothing but some partially permeable membrane in some fluid, so the blood that circulates in dialysis machine is the persons blood, and even if we were to say that the fluid inside the dialysis machine contains HIV,then even then the patient is safe, since the partially permeable membrane in its essence doesn't allow proteins which are way smaller than HIV virus ,so how is it gonna allow HIV in first place,

However, I would advise on revising this month, as school is approaching and so is CIE exams

Regards

 

[Emmris]

How would that happen? Duh
dialysis machine is nothing but some partially permeable membrane in some fluid, so the blood that circulates in dialysis machine is the persons blood, and even if we were to say that the fluid inside the dialysis machine contains HIV,then even then the patient is safe, since the partially permeable membrane in its essence doesn't allow proteins which are way smaller than HIV virus ,so how is it gonna allow HIV in first place,

However, I would advise on revising this month, as school is approaching and so is CIE exams

Regards

Wat I meant was abt the dialysis tubing ..... they don't change it for each patient do they

 

[Emmris]

How would that happen? Duh
dialysis machine is nothing but some partially permeable membrane in some fluid, so the blood that circulates in dialysis machine is the persons blood, and even if we were to say that the fluid inside the dialysis machine contains HIV,then even then the patient is safe, since the partially permeable membrane in its essence doesn't allow proteins which are way smaller than HIV virus ,so how is it gonna allow HIV in first place,

However, I would advise on revising this month, as school is approaching and so is CIE exams

Regards

N I am sitting 4 the exams next year ....

 

[Emmris]

How would that happen? Duh
dialysis machine is nothing but some partially permeable membrane in some fluid, so the blood that circulates in dialysis machine is the persons blood, and even if we were to say that the fluid inside the dialysis machine contains HIV,then even then the patient is safe, since the partially permeable membrane in its essence doesn't allow proteins which are way smaller than HIV virus ,so how is it gonna allow HIV in first place,

However, I would advise on revising this month, as school is approaching and so is CIE exams

Regards

I didn't say dat the dialysis fluid contains HIV ..... if someone who is HIV positive has got his blood cleaned in a dialysis machine .... after him, another person came 4 the treatment ....

 

[studyingrobot457]

I didn't say dat the dialysis fluid contains HIV ..... if someone who is HIV positive has got his blood cleaned in a dialysis machine .... after him, another person came 4 the treatment ....

They are sterilized.

 

[Emmris]

They are sterilized.

OK ..... thnx