# F215 - Revision thread 13th June 2011 watch

1. Right guys! You've all been working hard all day, so turn to channel 4 for some laughs
2. (Original post by heartskippedabeat)
I would say it's more likely to come up than the stuff that came up in june 10/jan 11, but i'm not sure. It's quite useful because it's just like another past paper
Hello again

Can you please explain how to work out the expected numbers from a set of data for chi squared?

This is what ive got:

Grey body/normal wing: 83 (observed)
Black body/ normal wing: 85 (observed)
Grey body/ bent wing: 78 (observed)
Black body/ bent wing: 74 (observed)

Total = 320
3. (Original post by ekta9)
What do you all know about succession? Just one example of primary succession right? If you used the Heinemann book then did you use sand dunes as that's more detailed?!
i just learn about sand dunes! embroyonic dunes or something then marram grass in yellow dunes blahblah....climax community, woodland
4. (Original post by intellectual1)
Yes it is...but remember the grade boundaries are very low 45 - 65 differentiates the E from the A...ou tof 100 marks...so as long as you know 70% of the specification you should be fine
That is really really crazy.. the difference between an E and A! Not that im complaining
5. (Original post by Rosi M)
Hello again

Can you please explain how to work out the expected numbers from a set of data for chi squared?

This is what ive got:

Grey body/normal wing: 83 (observed)
Black body/ normal wing: 85 (observed)
Grey body/ bent wing: 78 (observed)
Black body/ bent wing: 74 (observed)

Total = 320
Isnt it just 320/4? so expected numbers would be 80 for each

6. January 2011

F215/01 Control, Genomes and Environment (A2)
Raw 100 60 54 48 42 37 0
UMS 150 120 105 90 75 60

June 2010

F215/01 Control, Genomes and Environment (A2)
Raw 100 65 59 53 47 42 0
UMS 150 120 105 90 75 60 0

January 2011 - A was 60 out of 100...but B wwas 54 marks, and the C 48 marks...whilst the D was 42 marks and the E grade was 37 marks....seems like 5 or 6 RAW marks between each grade...

June 2010 - 65 marks for the A, but 59 marks for the B only 6 marks separated the A and the B!?! With the same 6 marks between the other grades as well...
7. You guys, i've gone over the past papers and im really confident these topics are going to come up on monday:
1. Apoptosis
2. Meiosis
3. Lac operon
4. Chi-squared x^2
5. Immobilised enzymes
6. Gene Therapy
7. Genetic engineering - Golden rice
8. Succession
9. Conservation
10. Galapagos and humans
11. The brain
12. Sliding filament model
13. Innate behaviour
14. Learned behaviour

I bet you any money they're going to come up... especially gene therapy
8. (Original post by emma237)
Isnt it just 320/4? so expected numbers would be 80 for each
Ok thanks

Does this apply with all of them? Because in the book, its a 93:1 ratio thing and they have turn 9/16 x 288 (total)??
9. (Original post by R.Fanatic)
You guys, i've gone over the past papers and im really confident these topics are going to come up on monday:
1. Apoptosis
2. Meiosis
3. Lac operon
4. Chi-squared x^2
5. Immobilised enzymes
6. Gene Therapy
7. Genetic engineering - Golden rice
8. Succession
9. Conservation
10. Galapagos and humans
11. The brain
12. Sliding filament model
13. Innate behaviour
14. Learned behaviour

I bet you any money they're going to come up... especially gene therapy
thanks, what are galapagos........\:
10. (Original post by Rosi M)
Ok thanks

Does this apply with all of them? Because in the book, its a 93:1 ratio thing and they have turn 9/16 x 288 (total)??
It depends on the expected ratio, if they expected 21 the expected numbers would be 160 80 80
11. (Original post by R.Fanatic)
You guys, i've gone over the past papers and im really confident these topics are going to come up on monday:
1. Apoptosis
2. Meiosis
3. Lac operon
4. Chi-squared x^2
5. Immobilised enzymes
6. Gene Therapy
7. Genetic engineering - Golden rice
8. Succession
9. Conservation
10. Galapagos and humans
11. The brain
12. Sliding filament model
13. Innate behaviour
14. Learned behaviour

I bet you any money they're going to come up... especially gene therapy

Wouldn't mind them topics but im worried about how tight mark schemes are and for stuff like gene therapy which hasnt come up, dont know how to word answers!
12. (Original post by rebeccalouise_92)
thanks, what are galapagos........\:
stuff about how humans have affected species on the Galapagos islands and all that..
13. (Original post by Rosi M)
Hello again

Can you please explain how to work out the expected numbers from a set of data for chi squared?

This is what ive got:

Grey body/normal wing: 83 (observed)
Black body/ normal wing: 85 (observed)
Grey body/ bent wing: 78 (observed)
Black body/ bent wing: 74 (observed)

Total = 320
Hello

I'm not too good on chi squared but I think you do you it like this

Because it's a dihybrid cross (I think ) you'd expect the ratio to be 93:1 like this- 9 both dominant genes : 3 dominant first gene recessive second gene : 3 recessive first dominant second : 1 both recessive

I don't know which out of grey/black is dominant but if we say grey is, and normal wings are:
So to work out the expected value of having both grey and normal wings you take 320 (total) divided by 16 (ratio total - 9+3+3+1) times by 9 (predicted ratio for grey and normal - both dominant)
This gives 180

Black/normal: 320/16 x 3 = 60
Grey/bent: 320/16 x 3 = 60
Black/bent: 320/16 x 1 = 20

To check, 180 + 60 + 60 + 20 = 320 (total)

Is that all you needed help with?
Someone else may be able to explain better, especially as i'm confused that the expected results are that different from the observed
14. (Original post by R.Fanatic)
You guys, i've gone over the past papers and im really confident these topics are going to come up on monday:
1. Apoptosis
2. Meiosis
3. Lac operon
4. Chi-squared x^2
5. Immobilised enzymes
6. Gene Therapy
7. Genetic engineering - Golden rice
8. Succession
9. Conservation
10. Galapagos and humans
11. The brain
12. Sliding filament model
13. Innate behaviour
14. Learned behaviour

I bet you any money they're going to come up... especially gene therapy
I would add cloning to that list, absolutely nothing from module 2 5.2.1 has come up whereas bits have come up from all of the other modules
15. (Original post by emma237)
I would add cloning to that list, absolutely nothing from module 2 5.2.1 has come up whereas bits have come up from all of the other modules
yeah, you're right. Cloning too.
16. (Original post by jak67m)

ANYONEEEEEEEEEEEEEEE!!!!!!!!!!!? ?????
You have to remember the ratio is 9:7 i think
Thats all i can remember off the top of my head lol
17. (Original post by R.Fanatic)
stuff about how humans have affected species on the Galapagos islands and all that..
thanks hunni xoxo
18. (Original post by rebeccalouise_92)
i just learn about sand dunes! embroyonic dunes or something then marram grass in yellow dunes blahblah....climax community, woodland
ahh okay thanks! I've sort of memorised how succession occurs at sand dunes
19. (Original post by R.Fanatic)
You guys, i've gone over the past papers and im really confident these topics are going to come up on monday:
1. Apoptosis
2. Meiosis
3. Lac operon
4. Chi-squared x^2
5. Immobilised enzymes
6. Gene Therapy
7. Genetic engineering - Golden rice
8. Succession
9. Conservation
10. Galapagos and humans
11. The brain
12. Sliding filament model
13. Innate behaviour
14. Learned behaviour
15. Cloning

I bet you any money they're going to come up... especially gene therapy
All in one paper, are you sure?? And some Innate behaviour was tested at the end of Jan 2011?
20. (Original post by emma237)
It depends on the expected ratio, if they expected 21 the expected numbers would be 160 80 80
Right ok thanks, i get it now

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