Environmental contaminants make their way into lakes, rivers, and groundwater and many other places. Animals drink that water. Our crops absorb that water that seeps into the soil, those crops are consumed by animals and humans. Therefore those animals are contaminated with whatever contaminant they consumed. In return those animals are ingested by the predator that consumes it therefore passing through the food chain.
Antibiotics are small molecules that are used to treat diseases that are caused by organisms
Vaccines are used to prevent infection to a particular disease.
Hope this helps!
the seeds in flowering plants come from ovules in the pistil of a female plant.
oxygen got into our atmosphere by algae that eats Carbon monoxide that in our air
