MATHS FOR BIOMEDICINE

[zibb3r]

This week's assignment (#2); is it just me, or is it really weird?

Are the difference equations for f^a(n+1) and f^A(n+1) reversed???  How do you do it?

[Limista]

This week's assignment (#2); is it just me, or is it really weird?

Are the difference equations for f^a(n+1) and f^A(n+1) reversed???  How do you do it?

What do you mean by 'reversed'? If you mean f^a(n+1) = 1- f^A(n+1), then yes you are correct.

How to do it --> calculate allele frequency of fa(n+1) from genotype frequency of faa(n+1) = p^2 according to hardy-weinburg

To get faa(n+1), refer back to the irreversible mutation lecture slides from week 2 (or wk 3, can't remember) that has the answer on it. 

You should find that fa(n+1) = p after solving the difference equation. 

[zibb3r]

What do you mean by 'reversed'? If you mean f^a(n+1) = 1- f^A(n+1), then yes you are correct.

How to do it --> calculate allele frequency of fa(n+1) from genotype frequency of faa(n+1) = p^2 according to hardy-weinburg

To get faa(n+1), refer back to the irreversible mutation lecture slides from week 2 (or wk 3, can't remember) that has the answer on it. 

You should find that fa(n+1) = p after solving the difference equation. 

Thanks Starfish!  Because  it is a recessive gene mutating to a dominant gene (a --> A) wont fa(n+1)=(1-u)fa(n) and fA(n+1)=(1-u)fA(n)+u?

Which is essentially the opposite of what is said in the lectures?  Because in the lectures they used a dominant gene mutating to a recessive gene (A --> a)?

Thanks

[Limista]

Thanks Starfish!  Because  it is a recessive gene mutating to a dominant gene (a --> A) wont fa(n+1)=(1-u)fa(n) and fA(n+1)=(1-u)fA(n)+u?

Which is essentially the opposite of what is said in the lectures?  Because in the lectures they used a dominant gene mutating to a recessive gene (A --> a)?

Thanks

yup that's completely correct!

Oh yes, I acknowledge that was the reverse. But the idea was the same - you just had to switch around the alleles being mutated & realise that this is an irreversible mutation (instead of reversible). Let's face it though, we were pretty much copying the lecture slide in answering this question 

[zibb3r]

yup that's completely correct!

Oh yes, I acknowledge that was the reverse. But the idea was the same - you just had to switch around the alleles being mutated & realise that this is an irreversible mutation (instead of reversible). Let's face it though, we were pretty much copying the lecture slide in answering this question 

Thanks so much   Can I ask what you wrote about 1C?  It seems like such a broad question?!

[Limista]

Thanks so much   Can I ask what you wrote about 1C?  It seems like such a broad question?!

Answer to this is also in the lecture notes. Do you remember when Anthony talked about how HW only applies to a single randomly mating population? He used the countries in the table to explain this..look it up