HELP with monohybrid crossing. Grade 10

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HELP with monohybrid crossing. Grade 10

Post by asiangabber » Mon Mar 28, 2011 10:08 pm

we did a jellybean lab about genetics. one of the bags of jelly beans had 5 beans. 3 were green and 2 were blue. would the phenotype ratio be 2:2? the genotype ration would be 2Gg : 2 gg?

the dominant allele is green.

one of the discussion questions are:
1. how can you explain the ration in the bag with 5 jellies?


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Post by canalon » Mon Mar 28, 2011 10:58 pm

maybe, your answer is possible. But I cannot say it is considering the amount of information you give.

1. the answer has all to do with the difference between absolute numbers (the numbers of counted jelly beans) and theoritical proportion. You might want to discuss the importance of sample size.

And it is ratio (no final n)

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)

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Post by DRT23 » Wed Mar 30, 2011 9:57 am

This is why geneticists use models like beans or Drosophila that have very high number of offspring at one time and replicate their experiements for many times.

Your answer seems correct. For an expected ratio of green 2:2 blue after crossing on notebook (I mean theoritically), you would expect 2 greens and 2 blues if there are 4 offsprings. What about the situation when there are 5 offsprings? 2 green and 2 blues and the last one has fifty-fifty chance for each colour (In other words, green 2.5:2.5 blue, so in real world there is not one with two colours together, so one of them should be either blue or green).

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