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The terms ‘discontinuous variation’ and ‘continuous variation’ are used in the description of the phenotypes of organisms - VCE - SSCE Biology - Question 2 - 2012 - Paper 1
Question 2
The terms ‘discontinuous variation’ and ‘continuous variation’ are used in the description of the phenotypes of organisms. Compare discontinuous and continuous varia... show full transcript
Worked Solution & Example Answer:The terms ‘discontinuous variation’ and ‘continuous variation’ are used in the description of the phenotypes of organisms - VCE - SSCE Biology - Question 2 - 2012 - Paper 1
Step 1
number of genes and/or alleles involved
Answer
In discontinuous variation, there is a small number of genes and/or alleles involved. This usually results in distinct phenotypic categories, leading to clear-cut differences between individuals.
In contrast, continuous variation involves many genes and/or alleles. This results in a range of phenotypes that merge into one another, commonly seen in traits like height or skin color.
Step 2
impact on phenotypes
Answer
Discontinuous variation typically results in few discrete phenotypes. For example, traits like blood type or flower color are either one form or another with no intermediate states.
On the other hand, continuous variation leads to many phenotypes that demonstrate a gradual transition. Traits such as weight and height exhibit a spectrum of variations due to the influence of multiple genetic factors.