AQA A2 BIOL5 22nd June 2012

Bright.Inspiration.

Question:
Insulin can be made using genetically modified bacteria. The human insulin gene is obtained from mRNA, rather than DNA. Suggest why. (2 marks)

Thanks in advance.

DNA contains introns becasue splicing has not taken place, whereas mRNA has only the coding DNA so all of it will code for insulin. :smile:

Reply 241

Bright.Inspiration.

10

Original post by kingam

Erm maybe when you splice the mRNA there will
Be no introns but DNA contains introns

mRNA already has been spliced (when it contains introns it's called pre-mRNA) so it doesn't contain introns anyway :smile:

Reply 242

ALevelGirl

Original post by Anamika19

Question:
Insulin can be made using genetically modified bacteria. The human insulin gene is obtained from mRNA, rather than DNA. Suggest why. (2 marks)

Thanks in advance.

From the cgp book, i understood that mRNA is used as most of the cells only contain 2 copies of each gene, so it'd be difficult to isolate the insulin gene from DNA. There are many mRna molecules in the cell though so its easier to obtain an mRNA and use it as a template to produce lots of DNA (using Reverse transcriptase)

Reply 243

heythereimannie

hey what do people think the essay question will be on? any predictions? :smile:

Reply 244

ALevelGirl

Getting a tad confused, for in vivo gene cloning, do we have to know about bacteriophage vectors as well as plasmids? Plasmids I understand but bacteriophage not so much. Is just extra information which I don't have to know for the exam?

Reply 245

F1's Finest

21

Original post by ALevelGirl

Getting a tad confused, for in vivo gene cloning, do we have to know about bacteriophage vectors as well as plasmids? Plasmids I understand but bacteriophage not so much. Is just extra information which I don't have to know for the exam?

only plasmids :smile:

For the essay you can refer to plasmids and viruses being used as vectors.

Reply 246

ALevelGirl

Original post by James A

only plasmids :smile:

For the essay you can refer to plasmids and viruses being used as vectors.

Thanks again James! Something I can cross off my revision list :smile:

Reply 247

ALevelGirl

The word stressed is an understatement of how I feel over this exam :frown:

Reply 248

Rahul.S

14

anyone got a site or sumthing.....so i can read already written essays.....I really cant be asked to write an essay....except during the exam :tongue:

Reply 249

F1's Finest

21

Original post by Rahul.S

anyone got a site or sumthing.....so i can read already written essays.....I really cant be asked to write an essay....except during the exam :tongue:

:

same, im too lazy man, but im gonna work my ass off for biology after my D1 exam tomorrow.

It could be the difference between me getting into uni and me missing the grade.

Im on a very low B so i need to ace biology...

Reply 250

Rahul.S

14

Original post by James A

:

same, im too lazy man, but im gonna work my ass off for biology after my D1 exam tomorrow.

It could be the difference between me getting into uni and me missing the grade.

Im on a very low B so i need to ace biology...

GL G

biology isnt part of any of my offers....but Ill do what I can. :redface:

Reply 251

Bright.Inspiration.

10

Original post by James A

:

same, im too lazy man, but im gonna work my ass off for biology after my D1 exam tomorrow.

It could be the difference between me getting into uni and me missing the grade.

Im on a very low B so i need to ace biology...

what do you need for uni?

I need an A, and for that I have to get like 95% or more in unit 4 and at least like 83% in unit 5 :frown:

FML FML FMLLLLLL

Reply 252

chill543

damn, being revising for last 2 weeks for other things, and tbh... ive forgot alot D:

Reply 253

F1's Finest

21

Original post by Rahul.S

GL G

biology isnt part of any of my offers....but Ill do what I can. :redface:

Cheers bro, best of luck to you.

Original post by Bright.Inspiration.

what do you need for uni?

I need an A, and for that I have to get like 95% or more in unit 4 and at least like 83% in unit 5 :frown:

FML FML FMLLLLLL

I need a B so I did loads of permutations and came to the conclusion that i need a B in Unit 4 and 110 ums in unit 5. It's a tough ask but i reckon i can do it....

Reply 254

05kubann

Original post by Bright.Inspiration.

what do you need for uni?

I need an A, and for that I have to get like 95% or more in unit 4 and at least like 83% in unit 5 :frown:

FML FML FMLLLLLL

ahh i'm in the same position as you. it sucks :frown:

the past papers are ridiculous

Reply 255

Evanesyne

12

Stressing out over the essay! So. Much. To. Remember.
Also so much to write, so little time :bawling:

Does anyone have a tip on how to write the essay more efficiently?

Reply 256

Patchey1000

2

Original post by Evanesyne

Stressing out over the essay! So. Much. To. Remember.
Also so much to write, so little time :bawling:

Does anyone have a tip on how to write the essay more efficiently?

Don't worry essay is 25/100 marks 9 very easy marks (correct spelling and grammar, science, breath) you have to to pretty bad to get under 12 right, if you get 2/3s of the rest of the questions 50/75 + 12 for the essay that's 62 which is an A

Reply 257

sydney07

Original post by Cath-ay

Hi there. unfortunately, there isn't a unit 5 paper for 2009 based on the current specification. This is because the new spec started in 2009 and the only papers released that year were for AS, not A2. However, if you are looking for more past papers to do, I'd advise doing the old spec papers (and maybe human biology papers) as a significant proportion of it overlaps with this course anyway. Hope this helps! :smile:

Ahh okay

Thank you

I will do, thank you again :smile:

Reply 258

Bright.Inspiration.

10

Original post by 05kubann