If the answers are different lab tools, then a scientist would use a microscope to exam and study details of protein molecules most likely 
        
             
        
        
        
The ridge of a birds breastbone is called a keel
        
             
        
        
        
Answer:
Cross overs can lead to formation of chromosome pairs that have no mutant allele.
Explanation:
Cross overs can lead to formation of chromosome pairs that have no mutant allele.
For example -
Suppose "X" is a mutant  allele and "x" is a mutant free allele.
Now when two homologous chromosomes contains a single mutant allele in different parts of the chromosome are crossed the following offspring are produced
X x
X XX Xx
x Xx xx
"xx" is a mutant free genotype.
Thus, crossing over can create a single mutation-free chromosome
 
        
             
        
        
        
Answer:
The star sm0313, was discovered using the ANU skymapper telescope at the siding spring observatory and later confirmed by the megellan telescope in Chile. Somewhat surprisingly, it's located a "mere" 6,000 thousand light-years away, they origins date back to the beginning of time.
 
        
                    
             
        
        
        
Answer:
cell cycle (become two cells) or not grow
Explanation: