Question

A researcher has hypothesized that the chemical tributyltin (an additive in boat paint) seeps out of the paint into the water and causes reproductive defects in developing marine snails. the experimental group consists of developing snails kept in a tank of water that has never been exposed to boat paint, and has typical levels of tributyltin added to it. the independent variable in this experiment is the presence or absence of:

Answer 1

The independent variable in this experiment is the presence or absence of tributyltin, which is hypothetically causing reproductive defects in marine snails and is a concern for environmental toxicology and endocrine disruption in aquatic ecosystems.

Step-by-step explanation:

The independent variable in this experiment is the presence or absence of tributyltin in the water. This variable is what the researcher is actively manipulating to determine its effect on the reproductive defects in developing marine snails. Tributyltin adds to the environmental toxicology concerns, as it might lead to endocrine disruption that can cause reproductive defects in marine organisms, just as PCBs and heavy metals have done in various aquatic ecosystems. Studies like the one of Kidd et al. (2007) have demonstrated population-level effects of endocrine disruptors on aquatic species such as fathead minnows, which could provide comparative insight into similar effects on marine snails due to tributyltin.