ALL CIE BIOLOGY DOUBTS HERE !!!

[astarmathsandphysics]

Add the uncertainties at either end. For instance, if your ruler measures to the nearest mm, that is +-0.5mm at either end so 1mm is the uncertainty and the meaurement is +-1mm

[WARRIOR]

Guys is this right , in the codons ,

A can be U or T or C
T can be A or G
C can be C or G
G can be T or C

Another question
There was a question in p1 that says we need only 8 essential amino acids , which chapter does it state that?

[Amelia]

Guys is this right , in the codons ,

A can be U or T or C
T can be A or G
C can be C or G
G can be T or C

I didn't quite understand what you mean by this question. But, during pairing of the DNA...

A binds with T and
C binds with G

in RNA the 'T' is replaced by 'U'.

Another question
There was a question in p1 that says we need only 8 essential amino acids , which chapter does it state that?

I guess, that statement was based on the question itself. There are 20 amino acids we know about, not 8.

[silvercameron]

can anyone pls give a description how starch/tile test is carried out??=S.i know about starch test using iodine solution and all but how is it carried out using a tile?and also,in case you get the wrong idea,it isnt about putting a leaf on tile and testing it.
my teacher told us all to get it tomorrow and i have no idea what it is.
Hope i get the answer soon.thanks!

[Deadly_king]

can anyone pls give a description how starch/tile test is carried out??=S.i know about starch test using iodine solution and all but how is it carried out using a tile?and also,in case you get the wrong idea,it isnt about putting a leaf on tile and testing it.
my teacher told us all to get it tomorrow and i have no idea what it is.
Hope i get the answer soon.thanks!

Here you are, it explains it well

http://www.footprints-science.co.uk/Starch.htm

Understand it first, then put it in your own words

COnfirmation : http://www.practicalbiology.org/areas/introductory/energy/photosynthesis/testing-leaves-for-starch-the-technique,73,EXP.html

[silvercameron]

THANKYOU deadlyking!!=)these websites are really good.
Thanks again!

[Deadly_king]

THANKYOU deadlyking!!=)these websites are really good.
Thanks again!

Anytime buddy

[UserWithACleverName]

I have trouble with the conversion questions...Like if they give a picture of a cell...When measured with a scale, its 3 cm long...How do I convert this value to micrometers...?

[aneeta]

Biology practicals on the 8th:'( any advice?
And can someone please explain serial dilution!?

[Amelia]

I have trouble with the conversion questions...Like if they give a picture of a cell...When measured with a scale, its 3 cm long...How do I convert this value to micrometers...?

Check out the conversion factors.

1 Centimeter = 10,000 Micrometers

1 Micrometer = 0.0001 Centimeters

Therefore, 3cm=30,000 micrometers.

Biology practicals on the 8th:'( any advice?
And can someone please explain serial dilution!?

Practicals are supposed to be easy papers. Practise plan diagrams and calculations

Serial Dilutions.

[minicooper]

Does anyone have specific advice on plan diagrams or taking readings? Such as, significant figures? How much detail does drawings of [magnified] cells require?

[Romeesa-Chan]

Does anyone have specific advice on plan diagrams or taking readings? Such as, significant figures? How much detail does drawings of [magnified] cells require?

I will try uploading some notes on it by day after tomorrow. Just send me a PM if I forget.

[Rvel Zahid]

Hi!
http://www.xtremepapers.com/CIE/International A And AS Level/9700 - Biology/9700_s03_qp_1.pdf
q, 7 , 18 and 25.

http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Biology%20(9700)/9700_s03_qp_2.pdf

http://www.xtremepapers.com/papers/CIE/Cambridge%20International%20A%20and%20AS%20Level/Biology%20(9700)/9700_s03_ms_1+2+3+4+5+6.pdf

Ans 6 c  part, marking scheme gives two answers for this question. which points to be considered.

Thank you.

[conquerpro]

can someone plzz solve this MCQ for me and explain?
a sample of swimming pool water contains 0.482 ppm of chlorine.this is equal to a percentage of
  A.0.000482
B.0.0000482
C.0.00000482
D.0.000000482
this is from edexcel chem 1
[/quote]

[Deadly_king]

can someone plzz solve this MCQ for me and explain?
a sample of swimming pool water contains 0.482 ppm of chlorine.this is equal to a percentage of
  A.0.000482
B.0.0000482
C.0.00000482
D.0.000000482
this is from edexcel chem 1

Answer is B.

ppm - particles per million meaning 10⁶
% - 100 meaning 10²

From here it's basic equation
Ans = (0.482/10⁶)*10² = 0.0000482