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AQA - BIOL4 - 13th JUNE 2014

Haha well both of my teachers at school have PHDs in Bio, and even they sometimes can't understand the long HSW questions near the end!! Thank God the grade boundaries are only around ~75% for an A*!

Oh.. That's obviously saying something then! The mark scheme can be SO strange sometimes that it favours people who may have not revised as much as others etcetc. Ah, all I want is a B in this, haha.

Reply 1381

heart17

1

Sorry I don't usually swear but wtf is that? How do we work out the rate? Is there like a easier way as its just 1 mark than having to remember fhdbdhhdbddhdhxhgajjwu=1? :wink:

Reply 1382

A sheesh

13

Do ppl teckon aqa will be obscure with qs like bio2?
Do u think boundaries will drop?

Reply 1383

Aardvark1998

18

Original post by Jaanu

Yep that makes sense! :smile:

Do u know why the energy transfer to carnivores is more efficient than producers?

Well producers are normally plants so their energy source is sunlight. But obviously the entire surface of the earth isn't made of plant leaves, so plenty of light never actually reaches the plant in the first place, lots of it is reflected away or is simply from the wrong direction. On the other hand, carnivores consume the vast majority of their energy source (ie. another animal) so the proportion of the energy that they consume out of what is available is higher.

Reply 1384

WheezyT

2

Original post by heart17

Sorry I don't usually swear but wtf is that? How do we work out the rate? Is there like a easier way as its just 1 mark than having to remember fhdbdhhdbddhdhxhgajjwu=1? :wink:

How to work out the rate on a graph?

Just do dy/dx

thats the difference in y over the difference in x,

so count the vertical squares and the horizontal squares forming a right angle triangle, divide vertical amount by horizontal

or this :smile:

https://www.youtube.com/watch?v=ykeCKm9JqSA

Reply 1385

WheezyT

2

Original post by Jaanu

Yep that makes sense! :smile:

Do u know why the energy transfer to carnivores is more efficient than producers?

Carnivores have a better digestive system, they can absorb nutrients better/easier and have more than 1 source of "food"

Producers only have one source of food, light, which has many variables e.g wavelength etc to deplete the amount of energy available.

Reply 1386

CakeIsthebest

1

Original post by A sheesh

Do ppl teckon aqa will be obscure with qs like bio2?
Do u think boundaries will drop?

I retook bio unit 2 and it was such an odd paper :L so much rage though on TSR afterwards

Reply 1387

Matbunny

1

Can someone please explain how to calculate the maximum growth rate in this question? The mark scheme says the answer is 40 but I don't understand why? ImageUploadedByStudent Room1402600086.129915.jpg

ImageUploadedByStudent Room1402600086.129915.jpg

Posted from TSR Mobile

Reply 1388

CakeIsthebest

1

Original post by WheezyT

How to work out the rate on a graph?

Just do dy/dx

thats the difference in y over the difference in x,

so count the vertical squares and the horizontal squares forming a right angle triangle, divide vertical amount by horizontal

or this :smile:

https://www.youtube.com/watch?v=ykeCKm9JqSA

Is that how you calculate the rate of anything which has a graph?! :redface:

Reply 1389

KatiexZoe

3

Original post by Kozmuss

Well... If in doubt on a question, the answer is large surface area to volume ratio!

Or Enzymes :biggrin:

Reply 1390

heart17

1

Original post by WheezyT

How to work out the rate on a graph?

Just do dy/dx

thats the difference in y over the difference in x,

so count the vertical squares and the horizontal squares forming a right angle triangle, divide vertical amount by horizontal

or this :smile:

https://www.youtube.com/watch?v=ykeCKm9JqSA

Hahaha, I just attempted that and I got 0.6? 3/5? And thank youuu

Reply 1391

WheezyT

2

Original post by CakeIsthebest

Is that how you calculate the rate of anything which has a graph?! :redface:

Yesssir

remember though they may say "between 1996 and 2002" so your "triangle" will be from 1996 and 2002 and where they meet

Reply 1392

KatiexZoe

3

Original post by Matbunny

Can someone please explain how to calculate the maximum growth rate in this question? The mark scheme says the answer is 40 but I don't understand why? ImageUploadedByStudent Room1402600086.129915.jpg

Posted from TSR Mobile

As it's asking for maximum growth rate you take the gradient of the steepest part of the curve. so id say go from 20 days to 25 days as this is most steepest and the points fall on nice points on the line. at 20 days, the mean mass of the caterpillars is 200mg, after 25 days its risen to 400. This is an increase of 200. Then there is a difference of 5 days, between 20 and 25, so all you have to do is work out the gradient of the line, which is up/along.. so 200/5= 40 :biggrin:

Reply 1393

Eternalized

1

Does anyone know if you can get marks for writing something not on the mark scheme?

E.g. June 2011 4bii) There's a table showing higher life expectancy in the UK when compared to Sudan and that females live longer compared to men respectively.
Would more more deaths of a younger population due to war in Sudan be an answer? Mark scheme does mention MALES have a lower life expectancy due to war but nothing about the entire population of Sudan having a lower live expectancy due to war. Seems pretty obvious as well.. :redface:

Reply 1394

CakeIsthebest

1

Original post by WheezyT

Yesssir

remember though they may say "between 1996 and 2002" so your "triangle" will be from 1996 and 2002 and where they meet