Living Environment Regents Practice Test

What might indicate the presence of toxins in the environment affecting wildlife?

1. Increased populations of apex predators.

2. Altered reproductive patterns in species.

3. Higher biodiversity in local habitats.

4. Fewer diseases observed in the population.

The correct answer is: Altered reproductive patterns in species.

Altered reproductive patterns in species is a significant indicator of the presence of environmental toxins impacting wildlife. Toxins can disrupt hormonal systems and reproductive functions, leading to changes such as reduced fertility, altered mating behaviors, and shifts in birth rates. These effects can manifest as decreased populations of certain species, either through fewer offspring being produced or congenital abnormalities affecting those that are born. Monitoring these reproductive changes can provide critical insight into the ecological health of an environment and signal potential toxicity that may be harming wildlife. The other options do not effectively indicate toxin presence. Increased populations of apex predators could suggest a healthy ecosystem with effective predator-prey dynamics, rather than toxicity. Higher biodiversity typically reflects a balanced ecosystem, which may not correlate with toxin presence. Finally, fewer diseases in a population might suggest a healthier environment, rather than serve as an indicator of toxins affecting the wildlife negatively. Thus, altered reproductive patterns serve as a more alarming signal of ecosystem distress due to toxins.