\begin{tabular}{l}8 What makes the relationship between genes and \\ traits complicated in humans? \\ \begin{tabular}{|l|l|l|}\hline Type Draw & \( \pm \) Speak \\ Enter answer here... I \end{tabular} \\ \hline\end{tabular}

1. **Polygenic Inheritance:** Many human traits are influenced by multiple genes. This means that rather than a one-to-one relationship between a gene and a trait, many genes contribute small effects to a single trait. For example, height is controlled by several genes acting together. 2. **Gene Interactions (Epistasis):** The effect of one gene can be modified by one or more other genes. This interaction, known as epistasis, makes predicting the outcome of genetic combinations more complex. 3. **Gene-Environment Interactions:** The environment often interacts with genes to influence traits. This relationship can be represented by \[ \text{Phenotype} = g(G, E) \] where \( G \) represents genetic factors and \( E \) represents environmental factors. Changes in either can significantly alter the trait. 4. **Epigenetics:** Beyond the DNA sequence, epigenetic modifications (such as DNA methylation) can affect gene expression. These modifications can be influenced by environmental factors and can sometimes be passed from one generation to the next, adding another layer of complexity to the relationship between genes and traits.