Answer:
Soil can become waterlogged. The water can cut off the air supply to the roots and to the organisms that live in the soil. If the roots do not receive enough oxygen, the plants will die because they rely on oxygen to complete photosynthesis. 
Explanation:
 
        
                    
             
        
        
        
Answer:
. A euglena survives on its own because it completes all life functions. A white blood cell cannot survive on its own because it is just one cell.
Explanation:
. A euglena survives on its own because it completes all life functions. A white blood cell cannot survive on its own because it is just one cell because A Euglena is a unicellular organism that can perform photosynthesis and complete cell activities. They live in fresh water, have eyespot, can excrete and have flagella for movement which are cellular activities
But a white blood cell cannot survive because it is one cell because it is produce from bone marrow and is a part of the immune system and work with other networks in the body system to fight against body infections.
 
        
             
        
        
        
<span>sperm and egg cells uniting to produce fertilized eggs</span>