Question

1. genetic variation is influenced by: only direct mutations gene exchange and epigenetic mechanisms environmental factors alone predetermined genetic patterns

Explanation:

Genetic variation is influenced by multiple factors. Gene - exchange during processes like meiosis and epigenetic mechanisms that modify gene expression without changing the DNA sequence contribute to it. Direct mutations are not the only cause, environmental factors interact with genetics and there are no fixed, predetermined genetic patterns that solely govern variation.

Answer:

Gene exchange and epigenetic mechanisms