I believe the correct answer from the choices listed above is the third option. It is oxygen that is a necessary reactant for cellular respiration to occur. Cellular respiration, in a sense, is breaking down sugar in the presence of oxygen.  Hope this answers the question.
        
                    
             
        
        
        
Answer:
0%
Explanation:
Round = Dominant
Wrinkled = recessive
Recessive = r
Dominant = R
homozygous dominant = RR
homozygous recessive = rr
Heterozygous= Rr
Since both seeds are homozygous recessive (rr) 
In your punnet square, one lower case r will go on the top and the left side 
      r    r
r
r
Something like that.
Go across your four boxes and you will end up with;
rr, rr
rr, rr
In order for it to be round, at least one box would need to have to be a heterozygous(Rr) or be a homozygous dominant.
 
        
             
        
        
        
Answer:
Global warming is caused by the greenhouse effect caused  by greenhouse gases, such as carbon dioxide, in the earth's lower atmosphere. A release of carbon dioxide into the atmosphere by carbon sources such as fossil fuel burning increases the greenhouse effect hence increased global warming. Another effect of higher carbon dioxide levels in the atmosphere is oceans acidification.  The oceans will absorb more carbon dioxide and form more carbon acid hence lowering the pH of the waters. To alleviate this phenomenon, carbon sinks need to be protected such as forest because they sequester carbon dioxide from the atmosphere and store it as carbohydrates in their biomass.  
Learn More;
To understand more on global warming checkout; 
brainly.com/question/9231468
brainly.com/question/7824762
#LearnWithBrainy
 
        
             
        
        
        
Answer:
need more info
Explanation:
jdjebehdudhebeurhdudhxudveudge uh r vi z uh d hu s usual gaudy gusto usurp disco
 
        
             
        
        
        
Unlike ionic bonds, covalent bonds involve the sharing of electrons between atoms.
- - Final answer: <span>b. sharing of electrons between atoms.</span>