Answer:
light
Explanation:
The above experiment is an investigation on the factors that affect photosynthesis which include carbon dioxide concentration,light intensity and quality,chlorophyll, water and temperature.Light was the independent variable. When the lant is moved to an area where light intensity is low, the rate of photosynthesis decreases.
After the experiment, oxygen gas is produced being a by-product of photosynthesis. Plants that are not adapted to an aquatic environment are not suitable for this experiment. The amount of carbon dioxide dissolved in water is low.
 
        
             
        
        
        
Fight or flight, because according to Hans Selye, this occurs at times of danger when your adrenaline is heightened.
        
             
        
        
        
The first, second, and fourth statements are correct.
        
             
        
        
        
Yes, it is a weak acid called the citric acid
        
             
        
        
        
Answer:
Atmosphere and geosphere is the part of the earth which is utilized in the nitrogen cycle. 
Explanation: 
In nitrogen cycle, the nitrogen which is present in the atmosphere comes down to the earth surface through rainfall. This nitrogen is absorbed by the earth and taken by roots of plants. Some amount of nitrogen is taken by many bacteria such as denitrifying bacteria which converts the soil nitrogen into atmospheric nitrogen and the nitrogen goes again to the atmosphere.