Answer:
The scientist is studying oxygen which can also be found in protien. oxygen is the element which makes up to 65% of human body mass. It is also found in proteins inside the body.
Answer:
Bacteria
Explanation:
All bacteria are microscopic (approx. 1 µm - 5 µms in size) and not visible with the n.aked eye. A microscope is needed to view them.
Answer:
Nitrate is the form of nitrogen most used by plants for growth and development. Nitrate is the form that can most easily be lost to groundwater. Ammonium taken in by plants is used directly in proteins. This form is not lost as easily from the soil
