The Student Room Group
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>

Edexcel IAL unit 3 Biology 6th May,2015

What are your predictions?Which core practical will come?
Are you all prepared?

Scroll to see replies

Original post by hiddensecrets
what are your predictions?which core practical will come?
Are you all prepared?


not exactly sure but wat do u think wud come?
Original post by Angelina1997
not exactly sure but wat do u think wud come?

I think mineral deficiency or tensile strength of plant fibres might come.
But its better to revise all of them just in case :biggrin:
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 :biggrin:


how do you know
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.
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.

yeah ur right!!
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 :biggrin:

yeah it's a bit difficult to guess i mean, i went through all past papers and so far all the practicals have been shown up in the papers soo we cant actually rely on guessing!!
lol, I just made a thread a few minutes ago and didn't know this one existed :bebored:http://www.thestudentroom.co.uk/showthread.php?t=3301451
Reply 8
Avatar for AJen2014
AJen2014
1
I think its mineral deficiency... but its very much better to revise all the practicals... good luck tomorrow guys..

1.

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?


1.

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?
paper 111.png116.1KB
teloo.png173.3KB
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..
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..


Okay if I chose 5, so 5/84 x 100 = 5.92, but then why would I divide that by 6?:confused:
I hope no tricky questions this time :s-smilie:
The latest papers are just getting tougher:colonhash:
(edited 8 years ago)
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?:confused:

they didnt divide it by 6, they rounded up the answer i.e 5.95 was rounded up to 6%
(edited 8 years ago)
Original post by hiddensecrets
they didnt divide it by 6, they rounded up the answer i.e 5.95 was rounded up to 6%

Great, Thanx
If anyone has any useful resources that they used to study for BIO unit 3 please post!!
Original post by majdalemon
If anyone has any useful resources that they used to study for BIO unit 3 please post!!

well, i hope u have all the core practicals
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??
Original post by AJen2014
I think its mineral deficiency... but its very much better to revise all the practicals... good luck tomorrow guys..

:wink: even i found out the trend as i went through all of the papers in order bt we can never say
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??

we got this as a handout from our bio teacher, hope it helps:
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

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you