ALL CIE BIOLOGY DOUBTS HERE !!!

[Amelia]

but isnt the conc of LH on day 9 already low? why do we need 2 decrease it further in order 2 prevent ovulation?
(sorry 4 asking 10 days later)

the concentration is LH is low on day 9 because of the treatment of antagonist of LH.

[shabie]

For CIE A2 (or AS) level students:

I was just going thru the marking schemes of Biology papers and what confuses me is that there are 4 points mentioned for a 2 mark question or sometimes 8 points mentioned for a 4-mark question. Now unlike chemistry or physics, sometimes they don't mention explicitly in their schemes that where all or some are needed so I am just wondering which one is the case? In chemistry and physics, as a general rule, you get one number for one point.

Because 8 points for a 4 point question seem quite a lot to me. They are basically all that you could write in response to that question which is usually not the case as students gets full points for writing different (but correct answers) that may or may not match the scheme.

So would anyone kindly clarify the schemes for biology? For example Question 5(c) for May/June 2010 Paper 42.

[iluvme]

Out of the 8 points given you could write any 4 points. As long as you have written 4 points you would get your 4 marks.
Its the same for the 2 mark question.

[sabrina]

hi
can anyone give some tips in paper 5 for bio. Its very tough.thanks in advance

[Amelia]

hi
can anyone give some tips in paper 5 for bio. Its very tough.thanks in advance

Paper 5 requires practical thinking and practise. Do the past papers and you'll be fine.

Good luck. 

[sabrina]

Paper 5 requires practical thinking and practise. Do the past papers and you'll be fine.

Good luck. 

thanks. i really hope so...............

[**RoRo**]

Can someone please draw for me the plan diagrams that you would draw for the stages of mitosis when you're viewing them from a slide?

Thanks in advance!

[Amelia]

Can someone please draw for me the plan diagrams that you would draw for the stages of mitosis when you're viewing them from a slide?

Thanks in advance!

Draw the diagrams in exactly the same way you view it in the microscope.

The cytoplasm... and then the stages of mitosis.

[**RoRo**]

Draw the diagrams in exactly the same way you view it in the microscope.

The cytoplasm... and then the stages of mitosis.

That's the thing, I want to know how would you represent prophase, interphase, telophase in a plan diagram.

Thanks anyways!

[HUSH1994]

can anyone explain MJ 2002 P1 Q21 please?

[Amelia]

can anyone explain MJ 2002 P1 Q21 please?

Can you post the question? I cant find that paper.

[**RoRo**]

I have a doubt in the circulatory system.

The heart's cardiac muscles are described as myogenic, right?
Myogenic means that the contraction of the muscles is initiated from the muscles itself and the term neurogenic means that the contraction of the muscles is initated from the nerves.

When we learnt the cardiac cycle, it was the SAN that received the impulse from the Cardiac Acceleratory/Inhibitory Center in the medulla oblongata of the brain which was transmitted through the vagus nerve till it reachs the SAN which sends the impulse to the walls of the atria to contract and the impulse is transmitted to the apex of the heart through the Purkinje fibres and the muscles contract, so as you see, it's contraction initiated by an impulse, so why is the cardiac muscle described as myogenic!

[Deadly_king]

I have a doubt in the circulatory system.

The heart's cardiac muscles are described as myogenic, right?
Myogenic means that the contraction of the muscles is initiated from the muscles itself and the term neurogenic means that the contraction of the muscles is initated from the nerves.

When we learnt the cardiac cycle, it was the SAN that received the impulse from the Cardiac Acceleratory/Inhibitory Center in the medulla oblongata of the brain which was transmitted through the vagus nerve till it reachs the SAN which sends the impulse to the walls of the atria to contract and the impulse is transmitted to the apex of the heart through the Purkinje fibres and the muscles contract, so as you see, it's contraction initiated by an impulse, so why is the cardiac muscle described as myogenic!

AM sorry I can't summarize it for you now since am pretty busy myselft......................but do read the first part of this

http://www.tutorvista.com/biology/physiology-of-the-human-heart

It is said that SAN is only partly controlled by sympathetic nerve.

Do not read everything koz I don't think it is in the \A-lvel syllabus
 

[**RoRo**]

AM sorry I can't summarize it for you now since am pretty busy myselft......................but do read the first part of this

http://www.tutorvista.com/biology/physiology-of-the-human-heart

It is said that SAN is only partly controlled by sympathetic nerve.

Do not read everything koz I don't think it is in the \A-lvel syllabus
 

Thanks a lot, actually my teacher had taught us the entire thing, it's pretty interesting.

& I got it, the contraction of the cardiac muscle starts from SAN which is a muscle by itself.

[**RoRo**]

Guys, someone make my day and reply with a 'no' to this question, do we need to know the structure of the trachea, cartilage and smooth muscle with all those amazing terms 'mucosa', 'chondrocytes', 'lacuna', 'cell nest', 'squamous pnemocyte type (1)' and 'secretory pnemocyte type (2)'?