Why are most of the mutations not expressed?

Explanation

### Step-by-Step Text Solution

1. **Understanding Mutations**: Mutations are changes in the DNA sequence that can occur due to various factors such as environmental influences or errors during DNA replication.

2. **Phenotype Expression**: The phenotype of an organism is the observable physical or biochemical characteristics, which are influenced by the genotype (the genetic makeup). Not all mutations lead to changes in the phenotype.

3. **Mutations in Non-Coding Regions**: Many mutations occur in stretches of DNA that do not have any known function, often referred to as non-coding regions. Since these regions do not code for proteins or have regulatory roles, mutations in these areas do not affect the organism's phenotype.

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