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AQA A2 Biology BIOL5 - 17th June 2015

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Could someone explain restriction mapping please?

Restrictionmapping Restriction mapping involves cutting DNA at variousdifferent recognition sitesFragments are then separated and identified with gelelectrophoresisWhen a plasmid is cut by R.E only one strand of DNA isproduced. Because of this combinations of R.E are used to cut the plasmid intotwo fragments. The size of the fragments produced depends on whichrestriction endonuclease are used Automation of DNAsequencing and restriction mapping Most DNA sequencing is carried out by machinesFluorescently labelled dyes are used by computerised systemsrather than radioactively labelled onesEach modified nucleotide has a colour associated with it sothat the whole process can be carried out in one test tubePCR cycles are used to speed up the processThe electrophoresis is carried out in a single narrowcapillary gel and the results are scanned by lasers and interpreted by computersoftware

Reply 1461

chemistrykid123

Original post by kiwi8397

if that syringe has drugs, aqa might ask you how they'll affect transmission across your synapses

dam you aqa dam you to hell

Reply 1462

bishopdon123

Anyone just cba with this exam?

Reply 1463

tofaeal

Original post by Bethany_

What does R mean? :angry:

It means restriction endonuclease

Reply 1464

shiney101

Should I look at breathing in insects/fish and also transport mediums from last year or would they be unlikely to come up?

Reply 1465

DecantedOrange

Can somebody sum up Action Potentials?

Reply 1466

Bustamove

Original post by sofja26

Hi I believe that Histamines- (within the white blood cells) they react to particular allergens e.g. pollen. This will increase permeability to capillaries e.g. swelling.

Prostaglandins (Cell membranes) Also dilate arteries causing swelling but these affect the pain receptors more due to injury by affecting blood pressure and transmission through neurones.

The key thing to remember here is that these are chemical mediators and these are different to hormones because they affect specific/ more direct to particular cells where hormones are more direct.

thanks

Reply 1467

thebest6633

Original post by bishopdon123

Anyone just cba with this exam?

yup

Reply 1468

ChemBios

Original post by eleanor97

Could someone explain restriction mapping please?

Would be appreciated.

Reply 1469

HopefulDentist..

Original post by bishopdon123

Anyone just cba with this exam?

Fallen asleep twice in my chair in the space of 4 hours :biggrin:

so yep

Reply 1470

tofaeal

Someone said on another thread that the R paper does not have a Q9 (15marks) as they do not have time to make a full paper

Reply 1471

kiwi8397

Original post by Bustamove

thanks

histamine causes itching and redness also

Reply 1472

halcyon3

would carbon dioxide and acidity be appropriate for an ions essay? also is kidney function in the spec or is it extra?

Reply 1473

sofja26

Original post by Bustamove

thanks

Sorry* When I said hormones are more direct I meant that they are more widespread :smile:

Reply 1474

Loveart99

If anyone is the slightest bit confused about PCR I found this website that has a great animation explaining it...

http://learn.genetics.utah.edu/content/labs/pcr/

Reply 1475

mujtaba.khokhar

Original post by tofaeal

Someone said on another thread that the R paper does not have a Q9 (15marks) as they do not have time to make a full paper

Hmmm.... how vaild is this?

they could just use and older topic from a past paper like they did in Biol 4 (used some questions from June 2010 paper)

Reply 1476

suyoof123

Original post by bishopdon123

Anyone just cba with this exam?

The fact that they pull out bs from their hidden spec to question us on how to play with graphs is the factor which makes me agree with you.

Its pathetic and I would advise anyone not to take bio.