AQA BIOL2~3rd June 2013~AS Biology (Now Closed)

Biologys definition of standard deviation is Stupid. :hand:

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Reply 601

Suzanna5678

Can someone please help with the oxygen dissociation curve thing in the most simplest terms possible getting really confused

Reply 602

Original post by Suzanna5678

Can someone please help with the oxygen dissociation curve thing in the most simplest terms possible getting really confused

You should try getrevising.com there are some really good resources on oxygen dissociation curves on there

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Reply 603

Original post by Suzanna5678

Can someone please help with the oxygen dissociation curve thing in the most simplest terms possible getting really confused

I remember someone saying about how they remember oxygen dissociation curves "Carbon Dioxide, that's right boring!".

Well, the further it is to the left, the easier it picks up oxygen, however, they are typically not as athletic because it has a higher affinity for oxygen than other animals. A common example AQA uses will either be Llamas or Birds of some sort.

They may compare it to animals which live close to sea level such as horses and humans.

So, llamas will have an oxygen dissociation curve further to the left because they can pick up oxygen easier than horses who would be to the right, however, the llamas would have a harder time releasing the oxygen from their haemoglobin. That's why you see horses running and not llamas - because horses can drop off oxygen to respiring cells easier. :tongue:

Understand?

(edited 10 years ago)

Reply 604

Could somebody tell me what we need to know about meiosis? Explain as if you're telling a child but use the correct terminology please hahah

Reply 605

Original post by lauraaaaa

Could somebody tell me what we need to know about meiosis? Explain as if you're telling a child but use the correct terminology please hahah

I will!!
Meiosis is the division of cells that produces four genetically NON-IDENTICAL daughter cells. These cells are the gametes (sex cells)
There are multiple stages of meiosis:

Interphase
Prophase1
Metaphase1
Anaphase1
Telophase1
Prophase2
Metaphase2
Anaphase2
Telophase2

Perhaps this picture will help??

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1369488049042.jpg65.1KB

Reply 606

Original post by lauraaaaa

Could somebody tell me what we need to know about meiosis? Explain as if you're telling a child but use the correct terminology please hahah

Please feel free to pm me

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Reply 607

bad8oy

14

Original post by eilish1903

I will!!
Meiosis is the division of cells that produces four genetically NON-IDENTICAL daughter cells. These cells are the gametes (sex cells)
There are multiple stages of meiosis:

Interphase
Prophase1
Metaphase1
Anaphase1
Telophase1
Prophase2
Metaphase2
Anaphase2
Telophase2

Perhaps this picture will help??

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We don't need to know about all the different stages of meiosis do we??

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Reply 608

P-121

Does anyone have any good revision sites for unit 2 - I'm getting bored with the textbook :redface:

Thanks

Reply 609

Original post by eilish1903

I will!!
Meiosis is the division of cells that produces four genetically NON-IDENTICAL daughter cells. These cells are the gametes (sex cells)
There are multiple stages of meiosis:

Interphase
Prophase1
Metaphase1
Anaphase1
Telophase1
Prophase2
Metaphase2
Anaphase2
Telophase2

Perhaps this picture will help??

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I know what happens in each of those stages because they are the same as mitosis, but is there an difference between meiosis 1 and meiosis 2 in terms of these stages? Sorry I can't read your diagram haha

Reply 610

Original post by lauraaaaa

I know what happens in each of those stages because they are the same as mitosis, but is there an difference between meiosis 1 and meiosis 2 in terms of these stages? Sorry I can't read your diagram haha

There isn't really a difference. It is just that Meiosis 1 goes straight into prophase and skips interphase completely.

Reply 611

Original post by Scienceisgood

There isn't really a difference. It is just that Meiosis 1 goes straight into prophase and skips interphase completely.

It does? My textbook doesn't say that :l

Reply 612

Original post by lauraaaaa

It does? My textbook doesn't say that :l

I think the way I worded it was completely disgusting...
Let me explain it again.

Meiosis 1 =

Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokenises

Meiosis 2 =
Prophase
Metaphase
Anaphase
Telophase
Cyotokenises

Note Meiosis 2 completely misses out interphase?

EDIT:
I attached an image of meisosis on here AGES ago, link is below;

http://www.thestudentroom.co.uk/attachment.php?attachmentid=208818&d=1365857522

EDIT2:
Typed into "Metaphase 2" rather than "Meiosis 2" by mistake! DX

(edited 10 years ago)

Reply 613

Original post by Scienceisgood

I think the way I worded it was completely disgusting...
Let me explain it again.

Meiosis 1 =

Interphase
Prophase
Metaphase
Anaphase
Telophase
Cytokenises

Meiosis 2 =
Prophase
Metaphase
Anaphase
Telophase
Cyotokenises

Note Metaphase 2 completely misses out interphase?

EDIT:
I attached an image of meisosis on here AGES ago, link is below;

http://www.thestudentroom.co.uk/attachment.php?attachmentid=208818&d=1365857522

You said meiosis 1 the first time! That's why I was confused! I basically just wanted to know when independent segregation (metaphase?) and crossing over (prophase) occur.

Reply 614

Sapphire123

Hi, i was wondering do we need to be able to draw the structure of beta glucose?

Reply 615

SonamH

Could someone help me out with question 4 from January 2010
The dissociation curve for people living at high altitudes (less oxygen) is towards the right of the the curve for people living at sea level (more oxygen). Surely the people living at high altitudes would have a higher affinity for oxygen than the people living at sea level so the curve for high altitude would be towards the left, but its not..
Could somebody explain why its not towards the left :s-smilie:

Reply 616

Original post by Sapphire123

Hi, i was wondering do we need to be able to draw the structure of beta glucose?

I doubt you would be asked to draw it, definitely identify but not draw. =l

Reply 617