[scoutzawwar]

(Original post by SnailFace)
That's not on the specification

I am pretty sure it is, have you not covered it?

[scoutzawwar]

(Original post by .snowflake.)
its not just me then. it's finding the motavation to revise biology is the difficult bit

I have a big booklet of past papers just begging to be filled, I just can't find the urge to avoid procrastinating and to start them. In the end I am barely able to do 2 of the papers.

[*_*]

(Original post by scoutzawwar)
I am pretty sure it is, have you not covered it?

I think because both context (SNAB) and concept led approach take the same exam, there might be differences in what we learn, but everyone can still get the marks.

[leogirl1992]

(Original post by scoutzawwar)
I have a big booklet of past papers just begging to be filled, I just can't find the urge to avoid procrastinating and to start them. In the end I am barely able to do 2 of the papers.

Let's work hard. My goal today is to finish 1 past paper for each Unit 4and 5.

[scoutzawwar]

(Original post by leogirl1992)
Let's work hard. My goal today is to finish 1 past paper for each Unit 4and 5.

You are giving your unit 5 also?

[This Honest]

(Original post by SnailFace)
That's not on the specification

It is.

I've seen them in past papers

[SnailFace]

(Original post by This Honest)
It is.

I've seen them in past papers

for unit 4 or 5?

[This Honest]

(Original post by SnailFace)
for unit 4 or 5?

Unit 4

[SnailFace]

(Original post by This Honest)
Unit 4

I have never heard of it. Here is the specification... please can you indicate where it is. I might just be being an idiot, but I don't see it.
http://www.edexcel.com/migrationdocu...4%20250510.pdf

[This Honest]

(Original post by SnailFace)
I have never heard of it. Here is the specification... please can you indicate where it is. I might just be being an idiot, but I don't see it.
http://www.edexcel.com/migrationdocu...4%20250510.pdf

Unit 4: point 13 and 14

It doesn't actually say cell mediated and humoral response but you would indirectly need to describe the process when prompted.

For example:

If a body is infected, how would it produce antibodies?

Here, you would explain the humoral response.

If a body is infected, how would it destroy the bacteria

Here, you would explain the cell mediated respone.

It should be in your textbook, the revision guide doesn't have it

[aym3n]

can anyone explain me the template and the sense strand part in transcription...i seem to get lost everytime i do it...i dont get how the diagram in the book explains that the coding strand is the antisense strand and will produce protein chains with codons from the other strand (non-coding strand)......but in the diagram (the big one on page 76 )...... this is not so......

also on page 74 it says that each thymine on the DNA strand codes for uracil in RNA but doesnt adenine on DNA code for uracil on RNA...

please help me either im very confused or there is something im not getting right
thankyou

[scoutzawwar]

(Original post by aym3n)
can anyone explain me the template and the sense strand part in transcription...i seem to get lost everytime i do it...i dont get how the diagram in the book explains that the coding strand is the antisense strand and will produce protein chains with codons from the other strand (non-coding strand)......but in the diagram (the big one on page 76 )...... this is not so......

also on page 74 it says that each thymine on the DNA strand codes for uracil in RNA but doesnt adenine on DNA code for uracil on RNA...

please help me either im very confused or there is something im not getting right
thankyou

What it means is that the thymine in the DNA stands for adenine in the mRNA strand, the adenine in the mRNA stand binds to the uracil in the tRNA.

TAT=AUA=UAU

see the difference?

[Tomatochuckers]

Personally I find the material alright in terms of difficulty, but I haven't properly started revising for it yet.

[aym3n]

(Original post by scoutzawwar)
What it means is that the thymine in the DNA stands for adenine in the mRNA strand, the adenine in the mRNA stand binds to the uracil in the tRNA.

TAT=AUA=UAU

see the difference?

okay yes i get that now...and what about the whole antisense and sense strands?....the diagram in the book confuses me

[This Honest]

(Original post by aym3n)
okay yes i get that now...and what about the whole antisense and sense strands?....the diagram in the book confuses me

an anitsense strand is like one of the DNA strands that have been broken off to be used to make mRNA via complementary base pairing

[leogirl1992]

(Original post by scoutzawwar)
You are giving your unit 5 also?

huh? giving? If you mean taking, then yeah.

[Tomatochuckers]

(Original post by This Honest)
an anitsense strand is like one of the DNA strands that have been broken off to be used to make mRNA via complementary base pairing

Man on fire

[This Honest]

(Original post by Tomatochuckers)
Man on fire

1 mark off an A at AS is my motivation to smash biology

[Tomatochuckers]

(Original post by This Honest)


1 mark off an A at AS is my motivation to smash biology

Hmm what let you down last year?

You are aiming for an A* mate, it's definitely possible IMO

[aym3n]

(Original post by This Honest)
an anitsense strand is like one of the DNA strands that have been broken off to be used to make mRNA via complementary base pairing

lol thanks i got that later