AQA A2 Biology BIOL5 - 17th June 2015

Original post by apuleius

Anyone got a cheeky unofficial markscheme 👌

Yessss! An official mark scheme will be great :smile:

Loved that biol 5 paper MA hahahahaa

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Reply 1881

Gr8banterm9

Wtf was the answer to the testosterone feedback system. I swear it could have been both negative and positive feedback. I out positive feedback as it causes more testosterone to be released which therefore deviates away from the "norm" which causes the hormones to be inhibited and therefore a decreases testosterone. So confusing and then the next question asked the same thing??

Reply 1882

Martin11

Original post by Faaiz Shah

I was gonna use letters but i am stupid so i forgot ahhah. I think i lost 1 mark on questionnaire and 3 on monoclonal and i think i got atleast 17 on essay
How about u bro??

I probably lost a mark on questionnaire, screwed anti body question, did okay in essay though few I probably messed up on like the one with transcription or the mice ones lol

Reply 1883

Plasmapause

12

Original post by bg9876

The importance to humans of controlling growth, development and reproduction of organisms. (something like that anyways)
I talked about intensive farming, preventing succession, tumour supressors and treating cystic fibrosis (process of making recombinant dna and using viruses etc) Do you think that is ok/irrelevant? Thanks!

I suppose so since involves organisms and growth and it's important to human in someway. At least that's what I assumed from the question/statement.

Reply 1884

biojames

Original post by anonlad

I think the van hijackers are the real heroes here

Yea I know I now look at van hijackers in a new light :biggrin:

Reply 1885

Original post by may_1

what did everyone put for the one about the IAA and describing why the root moved down because of the carrier proteins?

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cell L has more crrier protiens. So more iaa diffuses out of cell l. Cell l has low conc of iaa. Since high conc iaa cause inhibition of elongation, a lack of iaa will cause elongation. Left side grows faster then right. Roots bends...

Reply 1886

Martin11

Original post by may_1

what did everyone put for the one about the IAA and describing why the root moved down because of the carrier proteins?

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I said that the side with more carrier proteins produced more IAA so it inhibited that side, so other side would grow more causing it to elongate and move away from salt, probably wrong.

Reply 1887

Kittyflorence

3

I think I miss interpreted the question :frown:

I thought it meant like growth etc in humans and other organisms!!! So yours would all be rigjt :frown:

Reply 1888

Original post by Martin11

I probably lost a mark on questionnaire, screwed anti body question, did okay in essay though few I probably messed up on like the one with transcription or the mice ones lol

Oh yeah that methyl group thing. I bsed about transcrip factor not binding promoter. Rna polymerase cant fit comp free nucleotide. I think i got 1 for that maybe :smile:

Reply 1889

biojames

Few questions what did you all put for the question air. Why does sperm stop being produced when you introduce testosterone and why did the muscle contraction limit on the second question ?

Reply 1890

jessicasydes1

Original post by Bustamove

I did 10a).. spoke about

-Stimulus.. (I described reflex arc but I forgot to state reflexes? would I be penalised? I just said organisms respond to stimuli? ahh im a idiot)
Gave an example when humans touch something hot..

-Kensis and taxes of organisms,
kenesis responses to external temp
Taxes response to sunlight

(I forgot to talk about tropism, even though I wrote it in my plan)

-Ectotherms, endotherms.. how mammals increase heat when body temp is low (e.g. shivering)

-Homeostasis bull ****.. I waffelled about blood PH level... If high conc in C02, more CO2 breathed in so decreases blood PH, causes enzymes denature... counteracts by increase in respiration

-Natural selection and speciation.. (This is probably wrong, but I just said that this must take place for a species to adapt and survive to changes in the external environment? described speciation LOL)
Being cheeky here.. I probably didn't get marks for this point... but hey.. One tends to BS alot in exams....

How many marks do you think I'll get? I may flopped a little...what did you guys write?

I wrote about speciation and natural selection aswell! I couldn't think of anything for external so I had to waffle :teehee:

As long as we've really linked it to the title they'll award it something they're normal quite lenient.

Reply 1891

Martin11

Original post by Faaiz Shah

cell L has more crrier protiens. So more iaa diffuses out of cell l. Cell l has low conc of iaa. Since high conc iaa cause inhibition of elongation, a lack of iaa will cause elongation. Left side grows faster then right. Roots bends...

Ocrap I did this question wrong, I thought cell l made more IAA...go reading skills

Reply 1892

DecantedOrange

3

Original post by Gr8banterm9

Wtf was the answer to the testosterone feedback system. I swear it could have been both negative and positive feedback. I out positive feedback as it causes more testosterone to be released which therefore deviates away from the "norm" which causes the hormones to be inhibited and therefore a decreases testosterone. So confusing and then the next question asked the same thing??

More testosterone inhibits pituitary gland so no FSH/LH therefore no/less sperm or testosterone

Reply 1893

Original post by biojames

Few questions what did you all put for the question air. Why does sperm stop being produced when you introduce testosterone and why did the muscle contraction limit on the second question ?

Questionnaire
-parents will give untruthful awnsers
-leading biased questions

Testes
-inhibit reg centre
-less hpnr thing
-pituatry gland stimulated less
-less lh produced
-less ovulation????
Didnt know males had oestrous cycles ahahha

Muscle question??
Myosin filaments not held in place
Attach to actin and are just dragged along
Powerstoke doesnt take place.

Reply 1894

intrinsic

Original post by Faaiz Shah

Is the ratio 2.27:1 ???? ****!!!
I got 118:52 i think

It's technically the same thing but in biology, they want answers compared to 1 of the other.

Reply 1895

Original post by Martin11

Ocrap I did this question wrong, I thought cell l made more IAA...go reading skills

Ye i was literally crying when i saw that. Had to ask for extra paper and write another awnser.

Reply 1896

Original post by intrinsic

It's technically the same thing but in biology, they want answers compared to 1 of the other.

???i wrote 2.27:1 so hopefully.

Reply 1897

selenlee

Original post by bg9876

HI id did the second essay about humans controlling growth/reproduction development of organisms, just wondering if these are irrelevant/not answering the question? Thanks
Intensive farming
Preventing succession
Tumour suppressor cells/chemotherapy to prevent/treat spread of cancer etc
Using bacteria (cloning etc after making recombinant DNA) and altering adenovirus making it harmless to stop replication to treat cystic fibrosis?
Feel i got a bit waffley and irrelevant, had no idea what to put for first or second essay? Thanks

I talked about rate of photosynthesis being controlled in agriculture (optimum conditions) to get the best yield, linked to the second paragraph by talking about yield again but by using recombinant DNA for disease resistance, then controlling disease in humans using siRNA and finally contraceptive hormones like the oestrogen-progesterone pill and the progesterone implant and the reasons people want to delay having a baby. I wanted to talk about selective breeding but i felt like i would be jumping from topic to topic

Reply 1898

biojames