Which of the following is an example of bioremediation?
a.
using microorganisms to clean up an oil spill
b.
using bacteria to make yogurt
c.
creating plants that are resistant to bacteria
d.
adding nitrogen-fixing bacteria to the soil before planting crops

a.  using microorganisms to clean up an oil spill

Explanation:

Bioremediation is a process of treatment of a culture, biological medium, soil and water with plants and microorganism so as to remove the contaminants present in them. The plants and microorganism either absorb the contaminants or makes them potentially inactive which leads to decrease in pollution.  

a.  using microorganisms to clean up an oil spill is the correct option because the microorganisms will break up the bonds present in the oils therefore, making the structure unstable, unreactive and harmless to the aquatic species.

air enters through the nose, moves through the nasal cavity, the pharynx, the larynx, enters the trachea, moves through the bronchi andbronchioles till the alveoli.

a compound light microscope is used to magnify objects in steps.  

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