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A level Biology: Post your doubts here!

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2moora

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I face trouble solving paper 3 in biology my exam is on Wednesday and I dont know how to prepare for it what should I do??
and can anyone show me how to draw plan diagram in question 2 may/june variant 33
 
S

sumeru

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2moora said:
I face trouble solving paper 3 in biology my exam is on Wednesday and I dont know how to prepare for it what should I do??
and can anyone show me how to draw plan diagram in question 2 may/june variant 33
Click to expand...
Do you have excess to biology book of new edition.....you can find the ways for drawing plan diagram on the book......
 
joanna omar

joanna omar

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Heeey guyss how was ur Paper's 1/1 and 5/1

WE're allowed to discuss now ....Come on lets check our answers together !
 
GCE As and a level

GCE As and a level

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GUYS what was the answer for these questions in BIOLOGY/9700/paper 11
1- Which process is the least affected by a change in the fluidity of the membrane ?
2-What is the MINIMUM number of membranes that are crossed by oxygen and carbon dioxide molecules ?
3-some thing about the hemoglobin protein structure ( I think that which of the protein structures of the hemoglobin are codded by DNA or some ting like this )
 
NARIK SHAH

NARIK SHAH

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GCE As and a level said:
GUYS what was the answer for these questions in BIOLOGY/9700/paper 11
1- Which process is the least affected by a change in the fluidity of the membrane ?
2-What is the MINIMUM number of membranes that are crossed by oxygen and carbon dioxide molecules ?
3-some thing about the hemoglobin protein structure ( I think that which of the protein structures of the hemoglobin are codded by DNA or some ting like this )
Click to expand...


well No. 1 I'm doubting .. I guess I did wrong
No. 2 ...I marked in which there were 5 membranes for oxygen ..
bcuz
1. Into the cell of the alveolus
2. Out of the alveolus
3. Into cell of the capillary wall
4. Out of the cell of the capillary wall and into blood plasma
5. Into the red blood cell.
And No. 3 I don't xactly remember the question :/
 
xXGTZXx

xXGTZXx

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AmeeraKhan said:
Can someone please explain how polyploids are formed through hybridisation??
Click to expand...

Polyploids is when the chromosome number of an organism increase to more than 2n, if the it is an odd no. eg 3n, 5n they are infertile as they cannot undergo meiosis as homologous paring of chromosomes cannot take place. If it is even then homologous paring can take place and therefore they are fertile
Hybridization is when two gametes of different species are allowed to fuse together to form an offspring eg, is a mule it is formed from a horse and a donkey. Hybridized organism are usually show more better characteristics of both the parents the mule shows both the characteristics of the horse and donkey

Hybridized individuals are always infertile as they cannot undergo meiosis, but sometimes during the formation of gametes they skip meiosis and the gametes have 2 sets of chromosomes ie, 2n. if two individuals who undergo this faulty division mate the resulting offspring is polyploids

If you have the biology application booklet it is explained the genetic engineering section
 
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