Year 12s: what will be the first way you research your future options? >>

F215 - Revision thread 13th June 2011

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Reply 3240

ekta9

Not a single genetic diagram :frown:

Reply 3241

BeckyBaby

I agree with most people on here, really didn't like it. Its the way they seem to take small paragraphs of info from the text book and cover it over 4 pages that I hate. And there was sooo many topics that they didn't use! I crammed gene technologies/ genetic engineering and muscles etc. Just praying for low grade boundaries now!

Reply 3242

mintaero25

I have DEFINITELY lowered the grade boundaries...
Hopefully I've done well enough in the other modules...

Reply 3243

himmai

do u think the grade boundaries will b lowered

Reply 3244

Rocks:)

I'd just like to point out that I have Geography tomorrow which has 25/90 marks on ecosystems. By the end of this week I'll be as green as a cucumber...

Reply 3245

ejh1992

Original post by sappleby

Wasn't it you had to double the population first to give the number of alleles and then because there were 296 red that was 592 red alleles over the 692, which then gave 0.86 so the red was 0.86 and black was 0.14??

I'll be honest im not sure anymore, just got a bad feeling it was 0.92 and 0.08

Reply 3246

F.I

Original post by Rocks:)

I'd just like to point out that I have Geography tomorrow which has 25/90 marks on ecosystems. By the end of this week I'll be as green as a cucumber...

Reply 3247

NWA

Original post by Rocks:)

I'd just like to point out that I have Geography tomorrow which has 25/90 marks on ecosystems. By the end of this week I'll be as green as a cucumber...

I have this test tomorrow too!

Reply 3248

jungdao

Original post by ejh1992

I'll be honest im not sure anymore, just got a bad feeling it was 0.92 and 0.08

It was 0.92 and 0.08.

0.86 was q^2 (frequency of bb genotype for red bugs) and you had to square root that to get q (0.92).

Reply 3249

himmai

and y did people use the 296/346
instead of 50/346??

Reply 3250

J DOT A

I dropped about 46 marks that I know of. No chance of getting an A overall.

Reply 3251

angelbones

Original post by eddie90

for the evaluation of his conclusion i said that his statement was true cause it does show an increase at high altitudes possibly cause the black are better adapted to survive than reds but i said the conclusion was wrong as at high altitudes it doesnt cause them to survive it helps them too :s-smilie:

would i get any marks for saying that lol?

No, probably not. There actually was no real difference between the numbers of red and black if you converted them to percentages. They were all around 80% red, 20% black, which means his conclusion is incorrect.

Reply 3252

Tetanus

The answer is 0.92 for red and 0.08 for black.

296/(296+50) = q^2 = 0.85549....

rootANS = q = 0.924927...

so q = 0.92

p = 1 - 0.92 = 0.08

Reply 3253

kwindsor

Original post by mortysteve

Red = bb
296 = bb

296/346 = 0.855
q^2 = 0.855
q = 0.92

1-q = p
p = 0.08

q = 0.92
p = 0.08

Looking over the exam, I'm feeling pretty confident. At least 78/100. :smile:

gotta disagree with you on this one, there were only 3 marks and it seems you've over complicated it a bit. also if you do 50/392 it's not .08%
of course i could be wrong but this is just my opinion.

Reply 3254

Tetanus

Original post by himmai

and y did people use the 296/346
instead of 50/346??

Because the black type can exist as Homozygous Dominant BB or Heterozygous Bb...

Reply 3255

Jamesey

Original post by Rocks:)

I'd just like to point out that I have Geography tomorrow which has 25/90 marks on ecosystems. By the end of this week I'll be as green as a cucumber...

Oh I wouldn't worry, if its OCR you will probably get 4 or 5 questions on something truly obscure, like the distribution of crime in Uganda, or how toilet roll sales have been affecting the economy.

Reply 3256

786girl

WAITT

has everyone in the world done the paper???

we dont want people looking at the paper = doing well = raising grade boundaries = we all die
!!!!

just checkinggg

Reply 3257

Tetanus

Original post by kwindsor

gotta disagree with you on this one, there were only 3 marks and it seems you've over complicated it a bit. also if you do 50/392 it's not .08%
of course i could be wrong but this is just my opinion.

you are wrong.

Reply 3258

ejh1992

Original post by himmai

and y did people use the 296/346
instead of 50/346??

50/346 would be p2 + 2pq due to 50 being black and black was caused by the Dominant allele meaning only one dominant had to be present, only the red could be worked out as you knew the genotype