4) A study found that children with light-coloured eyes are likely to have parents with light-coloured eyes. On this basis, can we say anything about whether the light eye colour trait is dominant or recessive? Why or why not?

This is very interesting question, asked many times in exams…………
The observation that children with light-colored eyes are likely to have parents with light-colored eyes doesn’t provide conclusive information about whether the trait for light eye color is dominant or recessive. Eye color is a complex trait influenced by multiple genes, and its inheritance doesn’t follow a simple Mendelian pattern.

Mendelian inheritance involves the transmission of traits from one generation to the next based on the interaction of dominant and recessive alleles of a single gene. In the case of eye color, it is influenced by the interaction of multiple genes, each with multiple alleles. Additionally, environmental factors can also play a role in eye color determination.
The genetics of eye color are more accurately described as polygenic, meaning that multiple genes contribute to the phenotype (observable trait), and the interaction of these genes is not as straightforward as dominant or recessive. Therefore, eye color inheritance is more complex than a simple Mendelian trait.
While there may be a tendency for children to share eye color with their parents, this doesn’t necessarily mean that the trait follows a clear dominant or recessive pattern. It’s also worth noting that variations in eye color can occur even among individuals with the same eye color, indicating the complexity of the genetic and environmental factors involved.

In summary, based on the observation alone that children with light-colored eyes tend to have parents with light-colored eyes, we cannot definitively conclude whether the trait for light eye color is dominant or recessive without a more detailed understanding of the specific genes and alleles involved in eye color determination.