The third option, destroying cells
        
                    
             
        
        
        
Answer:
Carrying capacity
Explanation:
Carrying capacity is the limit to which a population can grow with the resources (food, water, oxygen, habitat space, etc.) are available to support them. Once they reach the maximum population that the environment can support, they reach their carrying capacity. 
 
        
             
        
        
        
Answer:
Radioactive dating uses radioactive elements to date matter such as rocks and fossils. As the radioactive elements disintegrate, they turn into other elements. Scientist then use the ratio of the two elements to determine how old something is.
Explanation:
 
        
             
        
        
        
Answer:
the pH
Explanation:
The condition that should not be kept the same in each of the five test tubes is the pH.
Since <u>the aim of the experiment is to investigate the effect of pH on the activity of the lipase enzyme</u>, the pH is, therefore, the <em>independent variable</em>. Thus, it must be controlled or varied in all the test tubes in order to see its effect on the activity of the enzyme, which, in this case, would be the dependent variable. 
 
        
             
        
        
        
Answer:
4
Explanation:
Mars Odyssey and Mars Express required spectrometric equipment that could analyze Mars's atmosphere