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OCR BIOLOGY GATEWAY B 25TH MAY 2016 B1 B2 B3 Exam

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O.25 y went up by 1 and x by 4
Reply 181
Avatar for negzi
negzi
9
Original post by notarealname2000
I did change in y / change in x and got 0.01. Anyone get anything similar or different


I got 0.0075
Because I did 1.6-1/1880-1800
Original post by Zoroarrkk
I couldn't think of advantages either, but I put those disadvantages. I think i said some crap like they can support each other in structure or something.

one advantage was that they don't need to be fertilised by insects to reproduce
I left myself 12 minutes for all 3 6 markers, so i must of only got 3 marks on each :/
I did 1 / 120 years and double checked it as 0.5 / 60 which I read off of the graph and got 0.0083, a few people that I know also got it but so many answers are varied...
Reply 185
Avatar for Jaazal
Jaazal
1
For the tree 6 mark question i put advantages: desirable characteristics can be passed to the other trees, more reliable reproduction than sexual reproduction with pollen. Disadvantages: reduction in gene pool, less variation, harmful recessive genes accumulate so the trees are more at risk from diseases, there will only be one gender of tree

With more explanation for each point
Reply 186
Avatar for samg2
samg2
4
Original post by ellamoon_22
PLACEBO SIX MARK

-blind trial
-placebo inactive pill(extra info)
-keep it Fair test/ experiment
-eliminates pscycological factors
-make sure drugs work and how it will affect humans
-given nicotine low mean reaction time on graph so quicker response by body against disease?
-given nicotine and told placebo bigger reaction time longer response to recover?


I was hesitant to put down blind trial because that's when the subject does not know if they're getting the placebo or drug but it said, even though the scientists lied, all were told they were getting a specific thing.

Anyone else the same?
The second one is either 0% or 25%...

I've messed up so badly on this paper ffs :frown:
It's always a relief to read though these and see other people getting the same answers you got XD
Original post by negzi
I got 0.0075
Because I did 1.6-1/1880-1800


Same :wink:!!!
QUOTE=samg2;65165853]I was hesitant to put down blind trial because that's when the subject does not know if they're getting the placebo or drug but it said, even though the scientists lied, all were told they were getting a specific thing.

Anyone else the same?

I get what u mean but I said blind trial cause they were lied to so not told specifically what they got idk but it doesn't hurt to write it down could be a potential Mark :h:
Anyone get anything for the genetic crosses (punnet squares)??
Reply 192
Avatar for AA11AAA
AA11AAA
Any predictions for the grade boundaries?
Original post by livsney
1940-1980


Yeah, that was the only phase where it was actually increasing only - other than 1800 - 1840 or whatever but that was too slow.
Can anyone tell me for the probability, but second one:

Did the mother have those weird thumbs or did she not?
I don't even know if I read the question -_- (the dominant allele one) I thought she did...
Original post by Gamer_44
Anyone get anything for the genetic crosses (punnet squares)??


50%
Original post by samg2
I was hesitant to put down blind trial because that's when the subject does not know if they're getting the placebo or drug but it said, even though the scientists lied, all were told they were getting a specific thing.

Anyone else the same?


I didn't say blind because both knew? Or at least some of them thought they did. It was for half of it but other half wasn't...

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(edited 7 years ago)
Is there an unofficial mark scheme yet?
Original post by AA11AAA
Any predictions for the grade boundaries?


55A* I think

Posted from TSR Mobile
Original post by Chittesh14
Can anyone tell me for the probability, but second one:

Did the mother have those weird thumbs or did she not?
I don't even know if I read the question -_- (the dominant allele one) I thought she did...


The mother didn't have it so she had tt, farther was Heterozygous so he must have Tt, therefore probability 50%. Either that or I read the question wrong.

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