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AQA - BIOL4 - 13th JUNE 2014

Reply 380

Velkoz

Jan 11 bio4
How do you do you do 1cii
2c
5b

Can't do these calculations

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Reply 381

Student 1

Is the UMS converter on the website accurate? I keep getting really high UMS scores on past papers (between 90-100UMS), it seems a bit unrealistic with some of my raw scores though? Or is it just that this paper has very low grade boundaries?

Reply 382

Regina15

2

Hope everyone's revision is going well, I got a high B last year, how much UMS roughly would I need to get on biol4 and 5 to get a B or to get an A?

Reply 383

Regina15

2

Original post by Student 1

Is the UMS converter on the website accurate? I keep getting really high UMS scores on past papers (between 90-100UMS), it seems a bit unrealistic with some of my raw scores though? Or is it just that this paper has very low grade boundaries?

Someone in my class was saying that some of them have very low grade boundaries, so it probably is just that :smile:

Reply 384

looloo4

Original post by Regina15

Hope everyone's revision is going well, I got a high B last year, how much UMS roughly would I need to get on biol4 and 5 to get a B or to get an A?

240 UMS is an A in A2, and so you will need to get this amount plus how ever many UMS off an A you were last year. (this is combination of biol4, biol5 and empa/isa, and so you can get lower on one but higher on the other)

Reply 385

Regina15

2

Original post by looloo4

240 UMS is an A in A2, and so you will need to get this amount plus how ever many UMS off an A you were last year. (this is combination of biol4, biol5 and empa/isa, and so you can get lower on one but higher on the other)

Okay, thank you!

Reply 386

Rhubarb96

anyone help on Q5c/d dont understand the answers, thanks :biggrin:

http://filestore.aqa.org.uk/subjects/AQA-BIOL4-W-QP-JAN10.PDF

Reply 387

Regina15

2

Original post by Rhubarb96

anyone help on Q5c/d dont understand the answers, thanks :biggrin:

http://filestore.aqa.org.uk/subjects/AQA-BIOL4-W-QP-JAN10.PDF

For question 5c) Perhaps reduced NAD provided hydrogen to form ethanol from pyruvic acid forming NAD in the process, so NAD is oxidised and pyrics acid is reduced - this is literally a guess!

Sorry didn't realise you said you didn't understand the answer: NAD is reduced because it has accepted hydrogens at some point. Going from pyruvic acid to ethanol- it gains 2 hydrogens (pyruvic acid has 4 hydrogens, ethanol has 6) so we know it must have gained the hydrogens at some point and in doing so is reduced, the only place it can get these in this case is from reduced NAD. In giving up it's hydrogens, NAD is oxidised.

Ps: hope this helps a little more :smile:

(edited 9 years ago)

Reply 388

Rhubarb96

why is energy transfer Efficiency lower in older animals/herbivores/ primary consumers/warm blooded animals/homoiotherms; ???

Reply 389

Student 1

Original post by Rhubarb96

why is energy transfer Efficiency lower in older animals/herbivores/ primary consumers/warm blooded animals/homoiotherms; ???

I can't understand that either :/

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Reply 390

WheezyT

2

Net CO2 levels at night time are higher due to Nocturnal Animals and no photosynthesis taking place.

No photosynthesis means no co2 is being absorbed via the stomata of the plan. Meaning there is a net gain.

During the day both plant and animals respire, but they plants photosynthesise. Meaning there less co2.

This is from a hsw question in a past paper right?

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Reply 391

blueberrysro

15

Just wondering if it's worth doing all the old pre 2010 Biol4 papers or not??? I had a glance through and they seemed somewhat different - would I be better of just re-doing all the post 2010 ones???
Thanks

Reply 392

looloo4

Original post by WheezyT

Net CO2 levels at night time are higher due to Nocturnal Animals and no photosynthesis taking place.

No photosynthesis means no co2 is being absorbed via the stomata of the plan. Meaning there is a net gain.

During the day both plant and animals respire, but they plants photosynthesise. Meaning there less co2.

This is from a hsw question in a past paper right?

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don't know if noctournal animals have anything to do with it? surely all animals respire at night whether they're noctounal or not

Reply 393

jacksw

Original post by Rhubarb96

why is energy transfer Efficiency lower in older animals/herbivores/ primary consumers/warm blooded animals/homoiotherms; ???

Do they use up more in maintaining homeostasis and metabolism?

(edited 9 years ago)

Reply 394

jacksw

Original post by blueberrysro

Just wondering if it's worth doing all the old pre 2010 Biol4 papers or not??? I had a glance through and they seemed somewhat different - would I be better of just re-doing all the post 2010 ones???
Thanks

Didnt the spec drastically change at some point in the past? I've only been doing 2010 onwards. and even then the 2010 papers seems different. Personal choice though. oh and i have no idea where you would even get pre 2010 papers from?!

Reply 395

pandabun

1

Original post by Rhubarb96

why is energy transfer Efficiency lower in older animals/herbivores/ primary consumers/warm blooded animals/homoiotherms; ???

Original post by Student 1

I can't understand that either :/

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Original post by jacksw

Do they use up more in maintaining homeostasis and metabolism?

I think this is correct; as they are using more energy for maintaining their body temperature, less energy goes into making biomass? So when another organism feeds on them, there's less energy thus the energy efficiency is lower.

Reply 396

jacksw

Original post by Velkoz

Jan 11 bio4
How do you do you do 1cii
2c
5b

Can't do these calculations

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p2 + 2pq + q2 = 1.0

p2 = 16% or 0.16 , which squared = 0.4
1.0 - 0.4 = 0.6 so q2 is 0.6
as it is 2pq you must times 0.6 by 0.4 twice. or...
2x0.4x0.6 = 0.48

See question 2d in june 2012 for another example

we know that p2 = 51% or 0.51 (remember to square it = 0.7)
therefore 1.0 - 0.7 = 0.3(q2)
so we do 2 x 0.3 x 0.7 = 0.42

(edited 9 years ago)

Reply 397

Rhubarb96

Original post by pandabun

I think this is correct; as they are using more energy for maintaining their body temperature, less energy goes into making biomass? So when another organism feeds on them, there's less energy thus the energy efficiency is lower.

thanks! i dont understand this either: Carnivores use more of their food than herbivores;

Reply 398

daniel1005

4

Does anyone have a summary of what's used and produced during each stage of respiration?

Reply 399

Sophie1994

6

Original post by Rhubarb96

yes i really need to do that for my essay... where are you reading this from? can you recommend any useful sources to get extra info for the essay? :smile:

Google. If there are topics I'm interested in, I just google it.

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AQA - BIOL4 - 13th JUNE 2014

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