Final answer:
Poisons and irritants can affect genes through various mechanisms, including causing mutations, altering gene expression, and inducing epigenetic changes. Exposure to these substances can have long-lasting effects on health and disease.
Step-by-step explanation:
Poisons and irritants can affect genes through various mechanisms. Some chemicals can directly damage the DNA, causing mutations that can alter gene function. Other chemicals can affect gene expression by altering the activity of enzymes involved in gene regulation. For example, some compounds can inhibit enzymes called histone deacetylases, which normally remove acetyl groups from histones and help control gene expression. This can lead to inappropriate activation of inflammatory genes, as seen in some autoimmune diseases.
Additionally, exposure to certain chemicals during pregnancy can result in epigenetic changes, which are heritable modifications to gene expression that do not involve changes to the DNA sequence. These changes can be passed down to subsequent generations and affect the expression of genes related to various health outcomes. For example, studies have shown that exposure to toxins in pregnant rats can lead to changes in gene expression in their offspring, resulting in increased susceptibility to certain illnesses.
Overall, poisons and irritants can have a range of effects on genes, including mutations, alterations in gene expression, and epigenetic changes, which can impact health and disease.