Natural selection acts by taking advantage of natural variations in the traits of organisms within a population. What is the ultimate source of this variation?
- Changes in the environment
- Mutations within the genetic code
- Response to a need of the organism
- Response the stress of competition for food
Leopards are fantastic swimmers and climbers. They are exposed to all contaminants present in the water system. Each year mercury compounds are released into the environment. Once it enters the water systems, bacterial convert it into an organic form and into the food web. Which of the following will happen to it?
- It will be evenly distributed throughout the food web
- It will be retained only in filter feeders of the aquatic system
- It will be retained mostly by the producers and herbivores
- It will have the highest concentration in the large secondary consumers