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AQA Biology B2 - Unofficial Mark Scheme

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Reply 380

Lucofthewoods

Original post by funky2722

no you probably forgot to divide by 100 becuase converting cm to m is ividing by 10000 not 100.

what answer did you get?

Reply 381

funky2722

Original post by Lucofthewoods

what answer did you get?

160,000 im 160,000% sure im right

Reply 382

Rylan110

For the Question about why organs xould be rejected the answers were

-Different DNA
-Different Tissue
-The body could see it as a foreign pathogen and attack it.

as long as you expanded those answers you will get 3/3!

Reply 383

Roquebrune2014

Original post by Rylan110

You need to mention antigens for 3/3

Posted from TSR Mobile

Reply 384

hansa123

Original post by funky2722

this is for the photosynthesis 6 mark question right?

yes and before you say its wrong my teacher said it

Reply 385

studentgcse2016

Original post by Spiket

Thats what i got and number seems reasonable for such a large area

i got that too, i hope its right however many of my friends got 16,000

Reply 386

sarah400001

Is there a B3 unofficial mark scheme

Reply 387

boio

Original post by humayra.a

I'm a little worried now after seeing what everyone wrote for the 6 mark question. I struggled a little on that question too, so left it till the end, and unfortunately, ran out of time too. So can anyone tell me approximately how many marks they think my answer will get me:

a) Plant the pondweed in some soil in a tub and leave it in a dark room. This is to make sure that no other factor affect (such as light shining from elsewhere) affects the rate of photosynthesis. (I know, pondweed in soil?? Makes no sense but idk why I wrote that)
b) Place the lamp in the room at a low intensity for one week.
c) Using the beaker measure, water the pondweed, however, make sure that you water the plant the same amount each time to ensure that different levels of water does not affect the rate of photosynthesis.

And that's as far as I got tbh :frown:

feeling kinda down now, it was that simple and I over-complicated!

lol I put to put the pondweed in soil aswell WTF LOL anyways I think the question was more hinting at including the independent variable, dependent variable and control variables and how to make the experiment as fair and accurate as possible like I reckon if you included all of them you'd defo get 3 marks, remember there's 1 mark for spag aswell :wink:

)

Reply 388

guy321

Original post by Blahblahblah7

That's what I put I think and I revised it quite well

Phenotype is whet you see e.g. Brown hair
Genotype is what's there e.g. Bb
And for Dad I put XY and mum is XX

F***, I know that mum is XX and dad is XY but I didn't put that. which question was that for?

Reply 389

funky2722

Original post by hansa123

yes and before you say its wrong my teacher said it

I'm not accusing you of anything, but has your teacher actually seen the question. Remeber they gave us the pondweed, ruler and some other stuff. The idea was to change light intensity by changing the distance, I hve no clue where you got a quadrat from. And I don't care if your teacher said it, she's probably just trying to prevent you getting moody.

Reply 390

hansa123

Original post by funky2722

well duh how else would she know sherlock and why wouldnt u use quadrats? it was a similar question to the last year 1 and it said how would u make the test valid and thats by using these and no i wouldn't get moody fyi every1 wrote about r they wrong as well?

I said that as well

Anyone got a mark scheme that is completed with marks ect?
Many thanks :-)

Reply 393

GCSE_core

Original post by Roquebrune2014

You need to mention antigens for 3/3

Posted from TSR Mobile

I don't remember seeing this, what question was this please and it what section?

Reply 394

funky2722

Original post by hansa123

which question are you on about?? THe 6 marker most definiely wasn't quadrats although there was a 3 marker on quadrat improvements,

Reply 395

GCSE_core

Original post by hansa123

The question last year was still an investigation question but measuring the distribution of organisms. No way would a quadrat be used for photosynthesis because there are plans/organisms to measure and you throw a quadrat on the floor. I'm afraid your teacher is wrong-hope you've done well though.

Reply 396

Athy_Obelia

Question 5 on alleles:

one question asked why it is not possible to treat a genetic disorder using the stem cells from the umbilical cord I think
I think there was another question on why it was more ethically right to use stem cells from umbilical cord rather than an embryo

Reply 397

Roquebrune2014

Original post by GCSE_core

I don't remember seeing this, what question was this please and it what section?

Don't know the question number, but it was the question about why a donor organ would be rejected, you need to say there are different antigens on the surface for a solid 3/3

Posted from TSR Mobile

Reply 398

GCSE_core

How many marks would I get for

In the beaker, measure out a set amount of water, and place the pondweed into this container. Using the ruler, measure a set distance between the beaker and the lamp. After regular intervals, measure how much water remains (the less water remaining the more the plant has photosynthesised). Repeat these steps increasig the distance between the light and the beaker. In the investigation you would have to control the starting amount of water, use the same light bulb, and leave the plant in the water for regular and consistent intervals.
Thanks

(edited 7 years ago)

Reply 399

GCSE_core

Original post by Roquebrune2014

Don't know the question number, but it was the question about why a donor organ would be rejected, you need to say there are different antigens on the surface for a solid 3/3

Posted from TSR Mobile

Was this the advantage of using stem cells from an umbilical cord in comparison to a donor question?

Are you sure you are talking about b2 and not b3?