The Student Room Group
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>

AQA Biology B2 - Unofficial Mark Scheme

Scroll to see replies

the gametes would be B and b for both because i dont think its asking about x and y
Original post by GCSE_core
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?


No it was definitely an organ question, I was replying to this:
ImageUploadedByStudent Room1465586340.196225.jpg

Maybe it was B3, it's all a blur now anyway...

For the advantage of stem cells one I put that it was quicker to treat them as there was no donor waiting list


Posted from TSR Mobile
Foundation mark scheme?
For the measurements ones...
there were 20 planktons
the quadrat was 25cm by 25 cm soooo... 625 cm^2... divide by 100 to get to meters to get 6.25m^2
And then so every m^2 there would be 3.2 planktons...
The total area of the field was i thibk 500m by 100m...or it could have been something else i cant remember so it came to 50000m^2
So the estimated number of plankons was 50000 X 3.2 = 160000
or it could have been 50000/3.2 to get 15625 (im not sure)
Hey guys i created a question paper thread with the relevant information required for the questions i think. Hopefully it will trig ur memories and help out the answers. Some questions are incomplete and would appreciate your help.
http://www.thestudentroom.co.uk/showthread.php?t=4157017&p=65655309#post65655309
Original post by Roquebrune2014
No it was definitely an organ question, I was replying to this:
ImageUploadedByStudent Room1465586340.196225.jpg

Maybe it was B3, it's all a blur now anyway...

For the advantage of stem cells one I put that it was quicker to treat them as there was no donor waiting list


Posted from TSR Mobile


I honestly don't remember this on B2, there's not much/nothing on antigens and organs.
I also put it was quicker as you wouldn't need a donor
Original post by GCSE_core
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.



omg i give up i don't want to fight with you so i hope u did well aswell
but then what did u write about?
Original post by hansa123
omg i give up i don't want to fight with you so i hope u did well aswell
but then what did u write about?


To make it a fairer/more accurate test to keep the starting amount of water in the beaker the same, leave the plant in the water for the same time, same light bulb intensity etc
Original post by GCSE_core
I honestly don't remember this on B2, there's not much/nothing on antigens and organs.
I also put it was quicker as you wouldn't need a donor


Yeah it probably was, sat them back to back so it's hard to remember, plus when I was revising I was basically treating B2+3 as one massive biology exam

Yay someone put it was quicker too!


Posted from TSR Mobile
Original post by GCSE_core
To make it a fairer/more accurate test to keep the starting amount of water in the beaker the same, leave the plant in the water for the same time, same light bulb intensity etc


This is the correct approach to the experiment question👍


Posted from TSR Mobile
Original post by Roquebrune2014
This is the correct approach to the experiment question👍


Posted from TSR Mobile


Thankyou so much! Hope you get the grade you're after😄
There was a question In the stem cell part that asked something like: "why is it better to use stem cells from the umbilical chord rather than the embryos in IVF?" And then the one after was "Why can't you treat someone's genetic disorder with their own individual stem cells?"
Original post by GCSE_core
To make it a fairer/more accurate test to keep the starting amount of water in the beaker the same, leave the plant in the water for the same time, same light bulb intensity etc


oh
Original post by Cakes717
I agree


would you say the genotype was heterozygous or homozygous and the gametes was Bb or bb
Original post by afghan-superman
Nope sorry, the gametes were the offspring, it was (BB Bb Bb bb) meaning only 25% chance of red hair


I put BB Bb Bb bb for the genotypes, but gametes are the sex cells, X Y for males and XX for females
Original post by GCSE_core
Thankyou so much! Hope you get the grade you're after😄


You're welcome! You too😀


Posted from TSR Mobile
Reply 416
Avatar for Aol1
Aol1
2
For the 6 mark question I wrote about iodine solution testing for starch and turning the leaves dark blue to see if photosynthesis has taken place. I said that I put the leaves in different light intensitys and then put them in beakers to see how long the solution took to turn blue and then recorded it. Does anyone know if they would accept this method?
Is there any chance you could put the number of marks next to each question so we can could, thanks.
Reply 418
Avatar for Rxkaa
Rxkaa
1
Original post by Blahblahblah7
The pictograms thing said that A is a cell then B is double its size then it spilits (C) so back to same size as A then that splits again

And D,E,F,G are sperm cells

So A = 6.6
B = 13.2
C = 6.6
And D onwards are 3.3 I think???


There wasnt a D, it just asked how many pictograms would be in a fertilised embryo, which was 6.6


Posted from TSR Mobile
Original post by MersennePrime
Is there any chance you could put the number of marks next to each question so we can could, thanks.


I agree please!!!!

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you