BIOL4 Biology Unit 4 Exam - 13th June 2011

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Reply 320

xbabycakes

Original post by coffee345

is anyone here doing BIOL5 revision as well?

I havent started revisiing for unit 5 yet :frown:

neither! I've got 3 exams on monday (including this one) so after that, purely biol 5!

Reply 321

kingsmod1

Original post by Rose1990

The questions gives, resus negative( phenotype/ genotype) does not give us allele frequency. Hardy weingberg is all to do with finding frequency of allele.

So resus negative= 16% =0.16
Q^2=0.16 ( Q^2 represent homozygous recessive genotype)
q=0.4 , p+q=1.
P=0.6. 2pq= 48%

This is how I make sense of this kind of questions. :dontknow:

why cant u do 1 - 0.16 straigt away like the others

some1 help?

Reply 322

Eloades11

Original post by tehsponge

LOL who just neg repped me for that? ****ing pathetic.

I know, some people don't really appreciate it when you're giving others help :rolleyes:

I have corrected the wrong and gave you a thumbs up :^_^:

Reply 323

Reccoshai

Hey guys, I never really wondered this myself until now, but can you like abbreviate molecules in exams like co2 intend of writing carbon dioxide? It just that by looking at the markschemes they right it abbreviated... sorry for the stupid question.

Reply 324

User12399

STOP NEGGING PEOPLE!!!!!

Original post by Reccoshai

You abbreviate Co2 and o2 and stuff but when it comes to things like GP, RuBP, I got told to write in once in full form them you can abbreviate them.

Reply 325

Reccoshai

Original post by User12399

STOP NEGGING PEOPLE!!!!!

You abbreviate Co2 and o2 and stuff but when it comes to things like GP, RuBP, I got told to write in once in full form them you can abbreviate them.

Thank alot! Really dont understand the people neg reping.,but anyways cheers its just that I always wrote the full form of everything and if I can write abbreviations of something I could really save time.

Reply 326

Rose1990

Original post by kingsmod1

why cant u do 1 - 0.16 straigt away like the others

some1 help?

There is difference between genotype (Bb) and allele(B)or (b)
p+q=1 ( this lets us work out the allele frequency)

P^2+2pq+p^2=1 ( this lets us predict genotype frequency)

The question you mentioned in earlier post, gives us genotype(0.16) and your asked to find heterozygous( 2pq).

p^2=0.16 ----> But to work out heterozygous ,we need "p" and not the square . (Rest of the solution in earlier post) Hope this helps.

Reply 327

ben10

what is the advantages of uses organic fertilliser?

Reply 328

Eloades11

Original post by User12399

You abbreviate Co2 and o2 and stuff but when it comes to things like GP, RuBP, I got told to write in once in full form them you can abbreviate them.

For AQA you don't have to remember the full names of Ribulose Bisphosphate or Triose Phosphate or the complicated names, it was mentioned at a conference and you only need to know the abbreviations for them(G-3-P, GALP, RuBP ect). Although the examiners will be happy if you know what they stand for!

Reply 329

BlindingLight

Original post by tehsponge

http://www.mediafire.com/?ynzizznywym
This was posted a while ago, its a file with like 500 pages of old spec questions.
Woops. Just realised that its unit 5.

Do you have a similar file for Unit 4? Thanks in advance.

Reply 330

Eloades11

Original post by ben10

what is the advantages of uses organic fertilliser?

Organic fetilisers are usually cheaper and have a longer lasting effect on the soil. Whereas other fertilisers like ammonia are more expensive and have to be applied more often.

Reply 331

tehsponge

Original post by Blackshadow

Do you have a similar file for Unit 4? Thanks in advance.

I don't have one, sorry. There will probably be one out there somewhere though...

Reply 332

tehsponge

Original post by Eloades11

Organic fetilisers are usually cheaper and have a longer lasting effect on the soil. Whereas other fertilisers like ammonia are more expensive and have to be applied more often.

Why is that? I would have thought inorganic nitrogen fertilisers would have to be applied less often because they can be engineered to provide enough nitrates to the crops?

Reply 333

Eloades11

Original post by tehsponge

Why is that? I would have thought inorganic nitrogen fertilisers would have to be applied less often because they can be engineered to provide enough nitrates to the crops?

Bacteria takes time to break down the organic fertilisers, so the plant absorbs the nutrients slowly. Whereas the inorganic ones just get absorbed straight away(or washed away by rain), and would need to be re-applied at specific intervals to keep sufficient growth of crops.