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Reply 1180
Has some one attempted January 2013 paper??
Concerning meiosis:

Crossing over occurs between a maternal and paternal chromosome where chromatids are exchanged between the two.

This occurs in metaphase 1 and 2. (Or only metaphase 1?)

Correct? Thanks!
Original post by BioMaths
Yessssssss, now you've got it! :smile:

Thanks angel !
Original post by Layontheland
As far as I'm aware has renal and hepatic arteries/veins been removed from the syllabus? Can someone clarify.


they're still in x
Original post by JackTheNerd
The current spec says this about it. First line of 'The blood system'


Thanks :biggrin:


Mass in diploid cell= 4.2 units

Mass in haploid cell (Gamete) = 2.1 units
Reply 1187
Original post by Tinuviel
Please tell me your predictions


My predictions? Or are you voting up the other dude?


The gamete would have 2.1 because it has half the amount of genetic material of a normal cell. The normal cell has 4.2, and the cell after DNA replication has 8.4.
Reply 1189


I always remember HAploid as HAlf.. Pretty stupid but it helps when in doubt!
Good luck on Monday!
Taxol is A drug used to treat cancer. Research scientists investigated the effect of injecting taxol on the growth of tumors in mice.

'Suggest and explain two factors which should be considered when deciding the number of mice used in this investigation?'

I thought the severity of the tumor/the size. But what else do you think could be one?
Reply 1191
Original post by JackTheNerd
Taxol is A drug used to treat cancer. Research scientists investigated the effect of injecting taxol on the growth of tumors in mice.

'Suggest and explain two factors which should be considered when deciding the number of mice used in this investigation?'

I thought the severity of the tumor/the size. But what else do you think could be one?


The age old "ethical consideration" and always a large sample size to improve reliability although I feel the latter isn't worded properly.. lol
Anything with animals and disease generally has the ethical bit in the MS somewhere.
Good luck!
Original post by tvomp2
Has some one attempted January 2013 paper??


Yes. Wasn't too bad i thought.
(edited 10 years ago)
Original post by PR11NCE
The age old "ethical consideration" and always a large sample size to improve reliability although I feel the latter isn't worded properly.. lol
Anything with animals and disease generally has the ethical bit in the MS somewhere.
Good luck!


I'd go with this too, but I'd say large sample size so it is representative maybe? Sounds better but both seem right. I'm sure the ethical considerations will be one though.


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Original post by Amenbreak321
The gamete would have 2.1 because it has half the amount of genetic material of a normal cell. The normal cell has 4.2, and the cell after DNA replication has 8.4.


But how do you know that a normal cell has 4.2?
Reply 1195
Original post by SchoolKid.
But how do you know that a normal cell has 4.2?


Have a quick read of the top section of P54 of the revision guide, it will help!
Original post by PR11NCE
Have a quick read of the top section of P54 of the revision guide, it will help!


Which revision guide is this?
Thanks I get it now :smile:
Reply 1198
Original post by SchoolKid.
Which revision guide is this?


The CGP one buddy. Sorry, I should've made that clear..
If you don't have it, just let me know i'll scan the page and attach it for you.
Original post by tvomp2
Has some one attempted January 2013 paper??


Yes i did and in fairness it wasn't the worst paper i had done the 6 marker was good, i honestly hated the january 2010 sea horse courtship question, some of the questions were quite confusing :redface:

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