Final answer:
Gene conversions and expansion/contraction of repetitive DNA are examples of directional, non-random mutations. Gene conversion involves the transfer of genetic information between non-allelic genes, while the expansion/contraction of repetitive DNA alters the number of repetitive DNA sequences.
Step-by-step explanation:
Gene conversions and expansion/contraction of repetitive (satellite) DNA are examples of directional, non-random mutations.
Gene conversion is a process where genetic information is transferred between non-allelic (non-identical) genes. It usually involves the conversion of one allele into the sequence of another allele. This process can result in the transfer of new genetic variations that can be beneficial, neutral, or detrimental to an organism.
The expansion or contraction of repetitive DNA, such as satellite DNA, involves the multiplication or reduction in the number of repetitive DNA sequences. This can occur due to specific genetic mechanisms, such as unequal crossing over or replication slippage. The changes in the number of repetitive DNA sequences can impact gene expression and function, leading to phenotypic changes in an organism.