An ecologist conducts<span> a </span>greenhouse experiment<span> to </span>study<span> the </span>effect<span> of nitrogen </span>concentration<span> on the</span>productivity<span> of </span>sunflower seedlings<span>. What is the </span>independent variable<span> in this </span>experiment<span>? make predictions about how nature works</span>
        
             
        
        
        
How continents shift position on Earth's surface.<span>Set forth in 1912 by Alfred Wegener, a geophysicist and meteorologist, continental drift also explained why look-alike animal and plant fossils, and similar rock formations, are found on different continents. </span>
        
             
        
        
        
I believe doubling the speed of the marble will increase the kinetic energy when it rolls down a ramp
Sorry if wrong
 
        
             
        
        
        
Answer:
Ionic bond
Explanation:
A bond formed by the electrical attraction between two oppositely charged ions is an Ionic bond.
 
        
             
        
        
        
Answer:
Increasing the substrate concentration.
Explanation:
Increasing the substrate concentration can increase the rate of the reaction to a certain point. However, once all of the enzymes bounded to the substrate, any further addition of it will not be going to affect or increase the rate of the reaction at all, as all the enzymes will be saturated and working in their maximum rates.