# Biology calculation

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#1
the haploid chromosome number in the koala is 8. independent assortment of chromosomes in meiosis contributes to genetic variation in the gametes of the koala. how many genetically different versions of koala gamete would it be possible for one individual to produce if independent assortment were the only source of variation?

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2 years ago
#2
(Original post by A*my)
the haploid chromosome number in the koala is 8. independent assortment of chromosomes in meiosis contributes to genetic variation in the gametes of the koala. how many genetically different versions of koala gamete would it be possible for one individual to produce if independent assortment were the only source of variation?

I believe the equation you're looking for is 2n where n = the number of pairs of homologous chromosomes

I'm not sure whether or not the number of homologous pairs would be the number of homologous pairs but presuming it is?

28 = 256 combinations

** edit ** my textbook suggests it would be 16 as meiosis starts with a cell that contains the diploid number...
216 = 65536??

do you have a mark scheme for your question?
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#3
(Original post by LiiHyde)
I believe the equation you're looking for is 2n where n = the number of pairs of homologous chromosomes

I'm not sure whether or not the number of homologous pairs would be the number of homologous pairs but presuming it is?

28 = 256 combinations

** edit ** my textbook suggests it would be 16 as meiosis starts with a cell that contains the diploid number...
216 = 65536??

do you have a mark scheme for your question?
0
2 years ago
#4
(Original post by A*my)
Oooh so 256 so that means you use the haploid number as the number of homologous pairs - I shall be making note of that thank you

This equation is in my AQA oxford published A level biology textbook

If you have the textbook I'm talking about it's on page 228 but I'll presume not and tell you what it says

Basically for 2n you're working out the different combinations for each one in the homologous pair going into one of the two cells that forms which is why you have 2 at the start always.

So 2n is what you use to work out only independent segregation

for working out the number of combinations when you factor in the random pairing of male and female gametes where you'd have done 2n individually in both the sperm and the egg you can do (2n)2 to work out the number of different combinations that you result in an offspring

A question might ask you about problems with this method of calculating as obviously it is flawed in that it can't take into account crossing over into it's calculations

Therefore these calculations are assuming that the chromosomes stay completely intact and no crossing over occurs

Hope this helps
1
#5
(Original post by LiiHyde)
Oooh so 256 so that means you use the haploid number as the number of homologous pairs - I shall be making note of that thank you

This equation is in my AQA oxford published A level biology textbook

If you have the textbook I'm talking about it's on page 228 but I'll presume not and tell you what it says

Basically for 2n you're working out the different combinations for each one in the homologous pair going into one of the two cells that forms which is why you have 2 at the start always.

So 2n is what you use to work out only independent segregation

for working out the number of combinations when you factor in the random pairing of male and female gametes where you'd have done 2n individually in both the sperm and the egg you can do (2n)2 to work out the number of different combinations that you result in an offspring

A question might ask you about problems with this method of calculating as obviously it is flawed in that it can't take into account crossing over into it's calculations

Therefore these calculations are assuming that the chromosomes stay completely intact and no crossing over occurs

Hope this helps
Thanks so much
1
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