Edexcel IAL unit 3 Biology 6th May,2015 Watch
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What are your predictions?Which core practical will come?
Are you all prepared?
Are you all prepared?
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#2
(Original post by hiddensecrets)
what are your predictions?which core practical will come?
Are you all prepared?
what are your predictions?which core practical will come?
Are you all prepared?
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(Original post by Angelina1997)
not exactly sure but wat do u think wud come?
not exactly sure but wat do u think wud come?
But its better to revise all of them just in case

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#4
(Original post by hiddensecrets)
I think mineral deficiency or tensile strength of plant fibres might come.
But its better to revise all of them just in case
I think mineral deficiency or tensile strength of plant fibres might come.
But its better to revise all of them just in case

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#5
Yes I'm prepared I think. Can't believe it's tomorrow!
No idea about the experiments, better to read through all than take a wild guess.
No idea about the experiments, better to read through all than take a wild guess.
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#6
(Original post by TheMadHatteress)
Yes I'm prepared I think. Can't believe it's tomorrow!
No idea about the experiments, better to read through all than take a wild guess.
Yes I'm prepared I think. Can't believe it's tomorrow!
No idea about the experiments, better to read through all than take a wild guess.
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#7
(Original post by hiddensecrets)
I think mineral deficiency or tensile strength of plant fibres might come.
But its better to revise all of them just in case
I think mineral deficiency or tensile strength of plant fibres might come.
But its better to revise all of them just in case

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#8
lol, I just made a thread a few minutes ago and didn't know this one existed
http://www.thestudentroom.co.uk/show....php?t=3301451

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#9
I think its mineral deficiency... but its very much better to revise all the practicals... good luck tomorrow guys..
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#10
- Could someone help me with this question from the June 2014 IAL Biology (WBI03) paper.
How did they get 110 days for B??? I don't get it?
- and for observing mitosis: in paper 6BI07 june 2013
Where's the 6th mitotic cell in the pic? and are the cells with 2 black dots considered as telophase. (circled in green) If so, why are they not counted as a mitotic cell, I have seen like 4 of them and they weren't considered in the markscheme?
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#11
Question 1 => for graph B, it returns to 1000 on day 160 and the varroacide was applied on day 50.
160-50 = 110 days
Question 2 => answer key accept 4,5 and 6.. so you should not confuse too much.. 5 answer would be brilliant for this question..
160-50 = 110 days
Question 2 => answer key accept 4,5 and 6.. so you should not confuse too much.. 5 answer would be brilliant for this question..
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#12
(Original post by biyoloji)
Question 1 => for graph B, it returns to 1000 on day 160 and the varroacide was applied on day 50.
160-50 = 110 days
Question 2 => answer key accept 4,5 and 6.. so you should not confuse too much.. 5 answer would be brilliant for this question..
Question 1 => for graph B, it returns to 1000 on day 160 and the varroacide was applied on day 50.
160-50 = 110 days
Question 2 => answer key accept 4,5 and 6.. so you should not confuse too much.. 5 answer would be brilliant for this question..

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I hope no tricky questions this time 
The latest papers are just getting tougher

The latest papers are just getting tougher

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(Original post by Adorable98)
Okay if I chose 5, so 5/84 x 100 = 5.92, but then why would I divide that by 6?
Okay if I chose 5, so 5/84 x 100 = 5.92, but then why would I divide that by 6?

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#15
(Original post by hiddensecrets)
they didnt divide it by 6, they rounded up the answer i.e 5.95 was rounded up to 6%
they didnt divide it by 6, they rounded up the answer i.e 5.95 was rounded up to 6%
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#16
If anyone has any useful resources that they used to study for BIO unit 3 please post!!
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#17
(Original post by majdalemon)
If anyone has any useful resources that they used to study for BIO unit 3 please post!!
If anyone has any useful resources that they used to study for BIO unit 3 please post!!
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#18
I'm slightly confused about the practical that relates to measuring the zone of inhibition under the presence of different extracts (garlic and mint). How do you spread the bacteria on the agar? Are there any specific techniques? And what about preparing that agar solution and pouring it into the dishes??
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#19
(Original post by AJen2014)
I think its mineral deficiency... but its very much better to revise all the practicals... good luck tomorrow guys..
I think its mineral deficiency... but its very much better to revise all the practicals... good luck tomorrow guys..

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#20
(Original post by majdalemon)
I'm slightly confused about the practical that relates to measuring the zone of inhibition under the presence of different extracts (garlic and mint). How do you spread the bacteria on the agar? Are there any specific techniques? And what about preparing that agar solution and pouring it into the dishes??
I'm slightly confused about the practical that relates to measuring the zone of inhibition under the presence of different extracts (garlic and mint). How do you spread the bacteria on the agar? Are there any specific techniques? And what about preparing that agar solution and pouring it into the dishes??
part 1(preparing agar medium)
1.liquefy the nutrient agar by placing the bottle in a water bath at 100c
2.once the agar has liquefied, remove the bottle and loosen the cap to allow air to escape.
3.all the agar to cool to about 45c
4.using a syringe, withdraw 1cm of bacterial broth and place it into a sterile petri dish using aseptic techniques
5.pour the molten agar into the petri dish so that it is half-filled
6.very gently push the petri dish back and forth to uniformly mix the bacteria and the agar
7.allow the agar to set by leaving it aside for about 20 minutes
Part 2
1.obtain plant extract by crushing 3g of plant material with 10cm3 of industrial denatured alcohol and shake it from time to time for 10 minutes
2. use a asyringe and withdraw 0.1cm3 of the extract onto a sterile disc cut out from a filter paper
3. let the paper discs dry for 10 minutes on an open sterile petri dish
4. repeat steps 1-3 for other plants, making separate test discs for each exctract
5. prepare once disc to act as control
6. using sterile forceps, place the test discs together with the control disc onto the medium in the petri dish
7. ensure that you can distinguish between the different discs by making the underside of the petri dish
8. close the etri dish and tape it to secure the lid with adhesive tape at 4 corners
9. incubate the dish for 24 hours at 30c
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