Mutations Question

Question

Describe how mutations can, but do not always, cause a change in phenotype.

Answer 1

Phenotype is defined as the set of traits that are actually expressed in an organism.  In other words, an allele* that is dominant (or codominant!) affects the phenotype, but a completely recessive allele is not expressed if there's a dominant allele for the same gene in the same organism.

 

In a nutshell, an organism receives two versions of each gene, one from each parent.  If the mutation is recessive, then it will not cause a change in the phenotype unless the gene from the other parent was also recessive.

 

*An allele is a version of a gene.  For example, "blond-haired" and "dark-haired" are alleles of the hair color gene.

 

p.s. If my answer seemed too complicated, or if you have any questions about it, please let me know so I can help you understand it better!