Which sentence best explains eutrophication? A. Bacteria are introduced to break down hydrocarbons in an oil spill.

B. Materials containing metal are toxic to organisms that live in them.

C. The Mercury contained in fish builds up in animals that eat the fish.

D. An increased growth in microorganisms results in oxygen depletion.

Dr. kaylan is an ecologist who studies bird behavior. she sets up an experiment to test which type of food crows are most likely to eat when given a choice between walnuts, corn, and sunflower seeds. to perform her experiment, dr. kaylan places three food bins in an area frequented by cows. each bin contains one of the three food types. then, she measures how much of each food type is eaten every day for a month and summarizes the results of her experiment in the pie chart below. based on her results, dr. kaylan concludes that crows choose to eat corn more frequently than other food sources because it has a higher nutritional value. what is a reasonable alternate conclusion that can be drawn from dr. kaylan's data

The concept of keystone species is controversial among ecologists because most organisms are highly interdependent. if each of the trophic levels is dependant on all others how can we say one is most important

What processes take place before the mature mrna exits the nucleus?