<span>The human population is increasing, so the likelihood of a mass extinction is also increasing.
The human population is increasing, and historically, as human population has increased, species have gone extinct. As human population increases, and also destroy more habitats to pay for higher standards of living, the probability of mass extinction increases. </span>
        
                    
             
        
        
        
Rolling a die multiple times to see the average.
        
             
        
        
        
Chloroplast and mitochondria. Only mitochondria is an animal.