Answer:
The bacteria found on roots, mainly on legumes, are related to the nitrogen cycle because nitrogen found in the environment is not usable by many species but because the bacteria can "fix" the nitrogen, it is usable by the plant which in turn it returned into the environment. 
Explanation:
 
        
             
        
        
        
Backcross, the mating of a hybrid organism, offspring of genetically unlike parents,with one of its parents or with an organism genetically similar to the parent.
        
             
        
        
        
<span>Roughly 5.6 years would be added to the average lifespan of the U.S. population. The test's lifespan increased from 719 to 770, or by 1.071. Multiplying the average lifespan by this amount would equal 84.609.</span>
        
                    
             
        
        
        
Answer:
The correct answer is - 38.15 gm of NaCl.
Explanation:
Write the balanced equation for this reaction of sodium (Na) and chlorine (Cl₂) to produce sodium chloride (NaCl):
2Na + Cl₂ —> 2NaCl
the mass of Na and the mass of NaCl :
Molar mass of Na = 23 g/mol
In the balanced equation = 2 × 23 = 46 g
Molar mass of NaCl = 23 + 35.5
= 58.5 g/mol
similarly in balanced equation = 2 × 58.5 = 117 g
From the balanced equation above,
46 g of Na reacted to produce 117 g of NaCl.
By converting it to 15 grams of Na.
Therefore,15 g of Na will react to produce = (15 × 117)/46 = 38.15 g of NaCl.
Thus, 38.15 g of Na
 
        
             
        
        
        
<h3><u>Answer;</u></h3>
acceleration= 2 m/s²
<h3><u>Explanation;</u></h3>
From the second Newton's Law of motion the resultant force is directly proportional to the rate of change in momentum.
That is;
F = ma 
Thus; F = 100 N, m = 50 kg 
a = F/m
   = 100/50 
   = 2 m/s²