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A level Biology: Post your doubts here!

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Hi everyone ,
I went yesterday through genetic crosses and today tried to solve some papers ,
in some questions they are using xx/xy when female/male involved and other crosses they are using crosses which involve other locus
like the question i posted below ,
any one has clue when to use xx/xy or eg use W^A /W^B ( i know this is not maths :cautious: )
and can someone do the question posted below?
 

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Hi everyone ,
I went yesterday through genetic crosses and today tried to solve some papers ,
in some questions they are using xx/xy when female/male involved and other crosses they are using crosses which involve other locus
like the question i posted below ,
any one has clue when to use xx/xy or eg use W^A /W^B ( i know this is not maths :cautious: )
and can someone do the question posted below?
when its linked to sex its X/Y, when you see homozygous/heterozygous its W^A/W^B, when you see dominant recessive its I/i

I'll go from left to right, top to bottom
key: W^A is resistant, W^B is susceptible

W^A W^B W^A W^B they must both be heterozygous because they have susceptible offspring
W^A W^B W^A W^B
W^A W^A W^A W^B W^B W^A W^B W^B now you put them the possible ways they can arrange
resistant resistant resistant susceptible only W^B W^B is susceptible because heterozygous is resistant too according to Q
 
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when its linked to sex its X/Y, when you see homozygous/heterozygous its W^A/W^B, when you see dominant recessive its I/i

I'll go from left to right, top to bottom
key: W^A is resistant, W^B is susceptible

W^A W^B W^A W^B they must both be heterozygous because they have susceptible offspring
W^A W^B W^A W^B
W^A W^A W^A W^B W^B W^A W^B W^B now you put them the possible ways they can arrange
resistant resistant resistant susceptible only W^B W^B is susceptible because heterozygous is resistant too according to Q
This question is related to sex , male and female ?
 
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Hey... someone please give me notes or any stuff on the highlighted syllabus outcome :O
We haven't done it in class >_<
thanks for the help in advance :`)Untitled.png
 
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Hey guysss.. if anyone still alivee..... o_O

well u got anything on speciation esp. sympatric speciation?? any help or notes will be greatly appreciated... thankss =)
 
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Hey guys, were can i find good practical notes for P3 and P5.... and how do you prepare for the questions in P4 section B?
 
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Hey guys, were can i find good practical notes for P3 and P5.... and how do you prepare for the questions in P4 section B?
for paper 5 have a look at this link please. I hope u get all the guide u need.
https://www.xtremepapers.com/community/threads/biology-paper-5-tips.27105/
For paper 4 section B, My teacher advised me : Do 2 question daily, i.e one paper write all the points in the correct order. and underline or highlight alll the important points, It will be easier for the examiner to see that u have covered up all the points, Plus explanations with diagrams. Diagrams are really very important. it carries quite a lot of marks. check wheter u have covered up all the answers as the mark schemme says. And one thing more. In part B there are many repeated questions in every paper. Mark them or highlight them U may not need to practise those agaian. u already have an answer to those questions so u may not repeat and learn from the previous answers

AND PLEASE Anyyonee I need any guiddes or points that will help me proceed with paper 5 as itss so HARD !
https://www.xtremepapers.com/community/threads/biology-paper-5-tips.27105/
 
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Hey guysss.. if anyone still alivee..... o_O

well u got anything on speciation esp. sympatric speciation?? any help or notes will be greatly appreciated... thankss =)
Which book do u use. ? the one which i have somewhat covers all the important points. U only need a few things to be learnt. Because the question based on this are repeated again and again in almost every paper in twisted ways. but the answers are the same.
 
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for paper 5 have a look at this link please. I hope u get all the guide u need.
https://www.xtremepapers.com/community/threads/biology-paper-5-tips.27105/
For paper 4 section B, My teacher advised me : Do 2 question daily, i.e one paper write all the points in the correct order. and underline or highlight alll the important points, It will be easier for the examiner to see that u have covered up all the points, Plus explanations with diagrams. Diagrams are really very important. it carries quite a lot of marks. check wheter u have covered up all the answers as the mark schemme says. And one thing more. In part B there are many repeated questions in every paper. Mark them or highlight them U may not need to practise those agaian. u already have an answer to those questions so u may not repeat and learn from the previous answers


https://www.xtremepapers.com/community/threads/biology-paper-5-tips.27105/
Thanks alot!!!
 
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for paper 5 have a look at this link please. I hope u get all the guide u need.
https://www.xtremepapers.com/community/threads/biology-paper-5-tips.27105/
For paper 4 section B, My teacher advised me : Do 2 question daily, i.e one paper write all the points in the correct order. and underline or highlight alll the important points, It will be easier for the examiner to see that u have covered up all the points, Plus explanations with diagrams. Diagrams are really very important. it carries quite a lot of marks. check wheter u have covered up all the answers as the mark schemme says. And one thing more. In part B there are many repeated questions in every paper. Mark them or highlight them U may not need to practise those agaian. u already have an answer to those questions so u may not repeat and learn from the previous answers


https://www.xtremepapers.com/community/threads/biology-paper-5-tips.27105/
By the way, can you kindly upload pics of your section B essays? I hope it's not too much to ask for....
 
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