The answer is that Both aid in the expansion and relaxation of lungs. Diaphragm and the rib muscles are vital in the breathing process. During inhalation the intercostal muscles contract, expanding the ribcage, the diaphragm contracts, pulling downwards to increase the volume of the chest, pressure inside the chest is lowered and air is sucked into the lungs. During exhalation the intercostal muscles relax, the ribcage drops inward and downwards, the diaphragm relaxes, moving back upwards, decreasing the volume of the chest, the pressure inside the chest increases and air is forced out. 
        
             
        
        
        
Answer:
Each component is in balance with the other components. As long as the components are in balance, the ecosystem can remain stable and healthy. Ecosystems may remain stable for many years if the different components are balanced.
 
        
                    
             
        
        
        
In meiosis I, homologous chromosomes separate, while in meiosis II, sister chromatids separate. Meiosis II produces 4 haploid daughter cells, whereas meiosis I produces 2 diploid daughter cells. Genetic recombination (crossing over) only occurs in meiosis I. D
 
        
                    
             
        
        
        
Errors can occur when the chromosomes segregate into the gametes during meiosis resulting in egg or sperm with too many or too few chromosomes. As a result, fertilised eggs and the ensuing embryos may have trisomy (an extra chromosome of a particular pair) in each cell or monosomy (one chromosome fewer in each cell).
 
        
                    
             
        
        
        
Answer:
I don't think you'll understand this but...
Explanation:
Think of it as Evolving A Pokemon.
If that doesn't help go to google type in your question (Make sure its simple) And it should Give you a simple answer.