AQA AS Biology Unit 2 - 1 June 2015

Scroll to see replies

Reply 980

wrfrew

Original post by benjenstark

No prob.

can you pls explain this again but a bit more detailed, i got this completely wrong lol bit worried now

Reply 981

lyricalvibe

Original post by kkboyk

Unit 1 is out of 60, right? so I,d say 57+

Most teachers would have dropped more than 3 marks + last year it was 51 it'll be around 50-53

Reply 982

kkboyk

Original post by maggie43

what about for unit 2?

Maybe 82+

Reply 983

Tee546

Original post by federer97

other than
coiled = compact
branched = sugars quickly released
insoluble = no affect on water potential
what is there for 6 marks?

easily hydrolysed into alpha glucose which is easily transported!

Reply 984

username1533709

Original post by Amyjonesx

I dont understand how completing an antibiotic course will get rid of all the bacteria?
If a person stops in the middle of the course and only resistant remain, surely these would not have been killed anyway by the antibiotic so how would completing the course change this?

Im sorry if my question isnt clear! i dont know how to explain what i mean

Posted from TSR Mobile
Using a larger dose of an antibiotic or using it over a longer time tends to kill the antibiotic resistant ones.
The resistant ones are stronger so they will be the last ones to die,so you must complete the.course.

Reply 985

kkboyk

Original post by lyricalvibe

Most teachers would have dropped more than 3 marks + last year it was 51 it'll be around 50-53

My teacheris extrenely harsh and pretty much made us get at least 55 to get 100%

Reply 986

wrfrew

Original post by kkboyk

Maybe 82+

hahah 70 to 75 for an a* i reckon

Reply 987

SamuelSingleton

Original post by kkboyk

Maybe 82+

its usually around the 70- 72 mark... that's ridiculously high and over ambitious

Reply 988

lyricalvibe

Original post by kkboyk

Maybe 82+

Once again, most teachers couldn't manage this due to bs points in the mark schemes.
Its usually 75-85%

(edited 8 years ago)

Reply 989

ecornwell97

My predictions for the 6-marker:
-How do plants limit water loss
-What factors affect transpiration
-Comparison between polysaccarides (cellulose/starch/glycogen)
-Movement of water in plants:
-root to xylem
-xylem to leaf
-Mitosis/meiosis

Reply 990

wrfrew

can someone please explain the precipitate point with the immunology classification method

Reply 991

lyricalvibe

Original post by kkboyk

My teacheris extrenely harsh and pretty much made us get at least 55 to get 100%

You're teacher taught you well man

Reply 992

kkboyk

Original post by SamuelSingleton

its usually around the 70- 72 mark... that's ridiculously high and over ambitious

Its not over ambitious though. I am gradually improving and reaching above 74 now.

(edited 8 years ago)

Reply 993

username1533709

Original post by kkboyk

Its not over ambitious though. I am gradually improving and rrachong above 74 now.

Posted from TSR Mobile

Do you want to be a mathematical biologist?

Reply 994

ecornwell97

Original post by wrfrew

can someone please explain the precipitate point with the immunology classification method

closer related the species, the more anti-gen anti-body complexes made between species A and C, these complexes form a precipitate, so the MORE precipitate the CLOSER related :smile:

Reply 995

kkboyk

Original post by lyricalvibe

You're teacher taught you well man

To tell you the truth, I revised most of the time out of fear of being kicked off the course (since they kept mentioning it, and were serious) :biggrin:

Reply 996

SamuelSingleton

Original post by kkboyk

Its not over ambitious though. I am gradually improving and rrachong above 74 now.

i'm not saying it's over ambitious for a person to achieve 82... i'm saying it would be overambitious for AQA to give full ums only to those who get (practically) full marks, anyone that sits an aqa paper will know that full marks it over ambitious due to the dead marks they throw in

Reply 997

benjenstark

Original post by wrfrew

can you pls explain this again but a bit more detailed, i got this completely wrong lol bit worried now

Heh, sure.

So, the similarity of organisms is due to DNA sequencing - ie, more closely related species have a higher percentage of similarity in their order of bases, their triplet code. Because a triplet codes for an amino acid - a primary structure - and polypeptides coil to make a protein, if a specific antibody can bind with this protein, this must mean two species are similar, and therefore related. Though it may be the same protein in two species, the base sequence may be slightly different, meaning the DNA is slightly different and therefore they are less closely related - this would form less precipitate. So the more precipitate formed, the more antibodies have binded, and the more closely related.

Hope this makes sense, and anyone feel free to correct me if I'm wrong.

Reply 998

kpd_98

Original post by wrfrew

can someone please explain the precipitate point with the immunology classification method

The more closely related the species are, the more precipitate is formed.

I think this is due to more antibody-antigen complexes being formed...

Reply 999

wrfrew

Original post by ecornwell97

closer related the species, the more anti-gen anti-body complexes made between species A and C, these complexes form a precipitate, so the MORE precipitate the CLOSER related :smile:

ahhh thank you!!