Human and the natural ones can change the ecosystem
        
             
        
        
        
The answer is a half-filled circle. 
In the pedigree charts, squares present males and circles present females. If a female is healthy, the circle is empty (white). If a female is affected with a trait, the circle is filled-in (usually black). However, if a female is a carrier of a disease, which means that one allele is dominant and one is recessive, then the circle is half-filled. 
        
                    
             
        
        
        
Answer: the cells differentiate
        
             
        
        
        
Answer:
no
Explanation:
they absorb our oxygen by the wind that blows so they can keep alive