Physics, Chemistry and Biology: Post your doubts here!

[rida.12.!!]

Chromatography...quite simple.Take Rf values and compare

i found the answer thx anyways!!

 

[esshven]

For Chemistry paper 6
The investigation question where we carry out our own experiment
Do we have to write it in an essay format or point form
Thanks

 

[Phoenix Blood]

What are non-endospemic seeds?

 

[Phoenix Blood]

For Chemistry paper 6
The investigation question where we carry out our own experiment
Do we have to write it in an essay format or point form
Thanks

Eitherway. You should cover the key points.

 

[Sweet!]

What are non-endospemic seeds?

these are the seeds in which endosperm(the part where all seeds store food) is absent. So the food is stored in the cotyledons instead, making them thick and fleshy.

 

[Sweet!]

how is double circulation efficient??

 

[esshven]

Thanks

 

[esshven]

W

View attachment 41793

what year paper is that .

 

[Ameena Eesa]

1. Why is the volume measured from up?



2. How can you tell tell that the liquid is colorless?



3. Pl explain how



4. Explain this too please



5. And this one toooo.............



6. And please explain (i) in this.........

Anyone?>...........
Awesome12

 

[Ameena Eesa]

the burette is measured from up cuz it's reading goes like:

and as for the coulourless potassium iodide, from my experience with solving past papers, i found out that any iodide salt solution is colourless
q.3 for this inheritance diagram i prefare drawing a table like this
View attachment 41828

but the question three is at present referring to mitosis and meiosis......... not inheritance

 

[Awesome12]

View attachment 41820

1. Why is the volume measured from up?

View attachment 41821

2. How can you tell tell that the liquid is colorless?

View attachment 41822

3. Pl explain how

View attachment 41823

4. Explain this too please

View attachment 41824

5. And this one toooo.............

View attachment 41825

6. And please explain (i) in this.........

Anyone?>...........
Awesome12

Well the first 2 have been explained
For
32) See meiosis results in gamete formation, right, so as you can see the genes are more of like splitting in W and Y
33) What does each of the line represent?
34) Now sickle cell anaemia can be homozygous or heterozygous. In the homo... condition, it is more likely to show its effect on the person (the person will die quickly) . In the heter... form, it is not that likely, and the person may survive.
So lets say a person has it in the homo.. form, he will have the genotype HaHa.
A person heterozygote for it will have a genotype HaHs.
A person with the genotype HsHs does not have it.

Malaria is a mutagenic agent, and it ill cause the mutation of genes
Thus in these areas, we will find more people with the condition; HaHa and HaHs (HaHa will be more than HaHs)

If we were to cross HaHs and HaHs, we would get
2 HaHa and 2 HsHs.

NOTE: the people with HaHa will die before and will not be able to reproduce

 

[Ameena Eesa]

Well the first 2 have been explained
For
32) See meiosis results in gamete formation, right, so as you can see the genes are more of like splitting in W and Y
33) What does each of the line represent?
34) Now sickle cell anaemia can be homozygous or heterozygous. In the homo... condition, it is more likely to show its effect on the person (the person will die quickly) . In the heter... form, it is not that likely, and the person may survive.
So lets say a person has it in the homo.. form, he will have the genotype HaHa.
A person heterozygote for it will have a genotype HaHs.
A person with the genotype HsHs does not have it.

Malaria is a mutagenic agent, and it ill cause the mutation of genes
Thus in these areas, we will find more people with the condition; HaHa and HaHs (HaHa will be more than HaHs)

If we were to cross HaHs and HaHs, we would get
2 HaHa and 2 HsHs.

NOTE: the people with HaHa will die before and will not be able to reproduce

Isn't it that the plasmodium in malaria needs oxygen to thrive on? So people with sickle-celled anemia have less oxygen carrying capacity due to the sickle-shape of their RBCs and so malaria can't attack them?

 

[Awesome12]

Can you please answer my questions too....

Post them here

 

[Ameena Eesa]

okay... here
Chemistry Paper 6 2012 q 4b, it says draw two intersecting lines for the graph, when i can only find one possible line to draw,
another one is.... this
View attachment 41840
and this too...
View attachment 41841

drawing intersecting lines means just joining your points with a straight line. the points maybe showing a trend of rising and falling. thus, rather than drawing it as a curve, we draw it as two intersecting straight lines.

 

[Ameena Eesa]

okay... here
Chemistry Paper 6 2012 q 4b, it says draw two intersecting lines for the graph, when i can only find one possible line to draw,
another one is.... this
View attachment 41840
and this too...
View attachment 41841

ans 6,

weigh mixture
add excess sulfuric acid
heat / stir
filter /wash / dry the carbon / residue (carbon residue will remain, and you will now measure mass of copper oxide left)
so... reweigh
calculate percentage of the mass left

 

[Ameena Eesa]

okay... here
Chemistry Paper 6 2012 q 4b, it says draw two intersecting lines for the graph, when i can only find one possible line to draw,
another one is.... this
View attachment 41840
and this too...
View attachment 41841

a, ii, colorless.
d, yelloe ppt, as iodide ions are formed
e, M is organic, its a fuel.....

check out with the ms. idk if im 100% correct

 

[Ameena Eesa]

ooh... but how did i conclude that it is an organic fuel? and for b the ms says "extinguished" any idea why?

its a fuel cuz its burning. its organic becuase of the yellow color and antiseptic smell i guess

 

[Ameena Eesa]

Awesome12

 

[Ameena Eesa]

yup yup this one. ahahahahhah i just stared at the question.

chill

 

[ibzer275]

anyone got revision notes for physics and chemistry paper 3 i never pass those papers