A level Biology: Post your doubts here!

[mariyam95]

Can you tell me which page on the syllabus says this?
Sigh Section B will be tough this year then

page no. 7 of 2013 syllabus

 

[MaxStudentALevel]

knowitall10 hahahahaha indeed i am xD

 

[Irfan1995]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_s12_qp_42.pdf
Q3b
Can u please explain?



Irfan1995

I don't really know what am I supposed to explain exactly.
They tell you in the question that the "tagged/labelled" nucleotides are present in low concentrations, so there's only a very small chance that they will be present in the first locus (spot).

 

[hela]

CAN ANYONE EXPLAIN
http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_s12_qp_13.pdf Q2
http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_w11_qp_11.pdf Q14 Q24

http://papers.xtremepapers.com/CIE/...nd AS Level/Biology (9700)/9700_s11_qp_11.pdf Q5 Q6 Q14
THANK YOU

 

[LMGD33]

http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Biology%20(9700)/9700_nos_as_1.pdf
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Biology (9700)/9700_nos_as_2.pdf
http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Biology%20(9700)/9700_nos_as_3.pdf
http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Biology%20(9700)/9700_nos_as_4.pdf
http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Biology%20(9700)/9700_nos_as_5.pdf

Here are 5 chapters, but I can't find the rest.

I'm sorry to bother, but I'm a private A-level candidate, and I didn't have a biology teacher all through this year and I'm just wondering.. What are those? I have never seen them before and they are clearly A-level material.. They are also very detailed almost too detailed.. I've been solving Past paper and doing alright with out them, should I study these as well?

EDIT : I realize that those are Applications of Biology, and I have studied them from my CIE and Mary Jones book, but these are faaaaaar too detailed..

 

[MaxStudentALevel]

dude section b before it included the core syllabus only but this year application syllabus will be included in section b... check out the syllabus !

SERIOUSLY??!?? THATS AWESOME.

 

[littlecloud11]

SERIOUSLY??!?? THATS AWESOME.

Which part exactly is the application part?

 

[LMGD33]

Which part exactly is the application part?

2 Applications of Biology
AS Level candidates will not be assessed on these sections.
A Level candidates will study and be assessed on all five sections, Q to U.
Q Biodiversity and Conservation
R Gene Technology
(includes some material originally in O)
S Biotechnology
T Crop Plants
U Aspects of Human Reproduction

 

[littlecloud11]

2 Applications of Biology
AS Level candidates will not be assessed on these sections.
A Level candidates will study and be assessed on all five sections, Q to U.
Q Biodiversity and Conservation
R Gene Technology
(includes some material originally in O)
S Biotechnology
T Crop Plants
U Aspects of Human Reproduction

Right, the last five chapters. Where is it mentioned that this year these will be included in section B?
Darn! I really like the original section B.

 

[LMGD33]

Right, the last five chapters. Where is it mentioned that this year these will be included in section B?
Darn! I really like the original section B.

I KNOWWW!! Almost always got full grades in section B, the easy 15 marks It says so on page 7, quoted below
Paper 4
This paper will consist of two sections.
Section A (85 marks)
will consist of a variable number of structured questions of variable mark value, based
on the A2 core and the Applications of Biology syllabus.
Section B (15 marks)
will consist of a free-response question, presented in an either/or form, that will carry
15 marks based on the A2 core and the Applications of Biology syllabus.

 

[littlecloud11]

I KNOWWW!! Almost always got full grades in section B, the easy 15 marks It says so on page 7, quoted below
Paper 4
This paper will consist of two sections.
Section A (85 marks)
will consist of a variable number of structured questions of variable mark value, based
on the A2 core and the Applications of Biology syllabus.
Section B (15 marks)
will consist of a free-response question, presented in an either/or form, that will carry
15 marks based on the A2 core and the Applications of Biology syllabus.

Wait a second, Either or Or question right? So one of them has to be from the care syllabus right?
Section B was the most blissful 15 marks.

 

[LMGD33]

Wait a second, Either or Or question right? So one of them has to be from the care syllabus right?
Section B was the most blissful 15 marks.

Nah, I think they mean that you could choose to solve either Q9 or Q10.. I sure do hope you're right and that not both are from the Applications, in that case it's core for me! Also, my old teacher stressed on my friends back in the UAE to pay more attention to the last chapter, especially IVF and the differences between spermatogenesis and oogenesis, she always got good hunches..
Nice to see a familiar face in the Bio thread littlecloud11

 

[littlecloud11]

Nah, I think they mean that you could choose to solve either Q9 or Q10.. I sure do hope you're right and that not both are from the Applications, in that case it's core for me! Also, my old teacher stressed on my friends back in the UAE to pay more attention to the last chapter, especially IVF and the differences between spermatogenesis and oogenesis, she always got good hunches..
Nice to see a familiar face in the Bio thread littlecloud11

Yup. I had the same feeling that this time we're likely to get a big question from the reproduction chapter.
I'm beginning to miss the old papers. So predictable.

 

[backtodev]

Can anyone give me a summary of what exactly goes on at the Loop Of Henle during the re-absorption of water?
My bio textbook is a bit confusing on this bit

 

[knowitall10]

Can anyone give me a summary of what exactly goes on at the Loop Of Henle during the re-absorption of water?
My bio textbook is a bit confusing on this bit

Remember that the loop of Henle is in the medulla- the most concentrated parts of the kidney, so the water potential of the tissue fluid is pretty low.
The loop of Henle has an ascending limb and a descending limb. We always start describing from the ascending limb. You see, the ascending limb is impermeable to water, but permeable to the ions Na+ and K+. S as the fluid moves up the ascending limb, Na+ and K+ are actively pumped out into the tissue fluid.this makes the tissue fluid almost four times as concentrated. The walls of the descending limb are permeable to water, so the water moves down its water potential gradient and into the tissue fluid. At the same time, sodium and potassium ions diffuse into the descending limb down their conc gradient. This is confusing right? Here's an elaborated version of the story:
The ascending limb is impermeable to water, but permeable to ions. E descending limb is permeable to both. So, first the ions are actively pumped into the tissue fluid from the ascending limb. Tissue fluid concentrated, so water potential lowered.
Naturally, water will move into the tissue fluid from the descending limb to decrease its conc. but then, lower conc will cause sodium and potassium ions to diffuse down their conc gradient into the urine in the descending limb.
Now the urine reaches the hairpin loop. And it is very conc now that there're so many ions and very less water. ( e longer the loop of Henle, the more conc the urine) now, it's gonna move up the ascending limb. Remember how the ascending limb is IMPERMAEABLE to water but PERMEABLE to ions? Yep, but this time, the ions will diffuse into the tissue fluid because the urine is just too concentrated. This causes a very highly conc tissue fluid ( see why these regions of the kidney are very conc?)
Thus, having two side by side limbs working together enables maximum conc to be built up both outside and inside the bottom of the loop. This is called, the counter-current multiplier...




I hope u understood...

 

[sandrawrr]

Using examples outline the need for energy in living organisms.
I'm not sure what to write..

 

[ShreeyaBeatz]

hey guys !
any predictions on paper 34 ?
from which topics is it likely to come from?

 

[Zari]

Asalamulalikum can anyone explain that what is the role of Potassium channels and Calcium ions during the secretion of Insulin ?

 

[pearl angel]

Could anyone PLEASE give me an explanation or help me understand the electron transportchain in respiration?

 

[ShootingStar]

can someone please explain the pregnancy test kit?