There is no variety in asexual reproduction 
        
             
        
        
        
Answer:
Explanation:
Ozone is a gas composed of three atoms of oxygen. Ozone occurs both in the Earth's upper atmosphere and at ground the level.Ozone at ground level is such a  harmful air pollutant, because of its  nasty effects on people and the environment, and it is the main ingredient in a type of air pollutant called “smog." 
 
        
             
        
        
        
Answer:
Discovered that DNA was in the shape of a double helix
 
        
                    
             
        
        
        
Answer:
 The correct answer is iron-transport proteins 
Explanation:
Siderophores are proteins produced by bacteria, and compete with the host's iron-transport proteins. They aim to bind and "hijack" the host's cell iron molecules for their own pathogenic cell processes 
 
        
             
        
        
        
I think I understand even without the picture. I'll add a picture of the Punnett Square filled in, but what you're crossing is
Tt  x  tt (heterozygous crossed with a homozygous recessive)
The ratio you get in the end is 2 heterozygous (Tt) and 2 homozygous (tt) offspring, so the ratio is 1:1.
So the percentage of offspring that are homozygous recessive is 50%.