Question

Explain why observed ratios often differ from expected ratios especially when there are small number of offsprings? ​

Answer 1

Explanation:

However, because the alleles BV and bv are linked, the observed phenotypic ratio is much different (5:1:1:5) than the expected ratio. ... The consequence of this is that these gene alleles are much less likely to segregate independently into gametes.

Answer 2

Answer: The genetic diagram only shows the probability of the phenotypes. It is possible by chance to end up with more or fewer of each phenotype, therefore the actual ratio can differ from the predicted ratio.

Explanation: For example if a heterozygous parent Bb with brown eye colour phenotype mates with a recessive phenotype, green bb, then for each offspring there is a chance of phenotype brown 50% and green 50%. for each offspring there is a chance to end up with more or fewer of either the phenotype. If the sample size is small then the actual ratio usually differs from predicted ratio.