Answer:
1.The pleural cavity aids optimal functioning of the lugs during breathing. It transmits movements of the chest wall to the lungs, particularly during heavy breathing. The closely approved chest wall transmits pressures to the visceral pleural surface and hence to the lung (10-19.
2.The diaphragm, located below the lungs, is the major muscle of respiration. It is a large, dome-shaped muscle that contracts rhythmically and continually, and most of the time, involuntarily. Upon inhalation, the diaphragm contracts and flattens and the chest cavity enlarge.
Explanation:
 
        
                    
             
        
        
        
Answer:
these differentiate as a result of signaling mechanisms. ... The daughter cells divides and after each division it becomes more specialized. When it reaches a mature cell type downstream (for example, becomes a red blood cell) it will no longer divide.
 
        
                    
             
        
        
        
An oxbow lake. An oxbow lake forms when the meander of a river is cut off from the main channel
        
                    
             
        
        
        
Answer: The genotype ratio is 2Ff : 2ff
The phenotype ratio is two normal feathered birds to two silky feathered birds.
Explanation: Let F represent the gene for normal feather and f represent the gene for silky feather. F is dominant while f is recessive, therefore a male that is hybrid for trait of normal feather is heterozygous and will have a genotype of Ff, a female that is homozygous for silky feather will have a genotype of ff. 
A cross between Ff and ff will yield 2Ff birds and 2ff birds. Since F is dominant, a bird having genotype of Ff will manifest outwardly as blue feathered birds while ff will manifest outwardly as silky feathered birds because f is recessive and must occur in a homozygous condition in order to manifest phenotypically. Therefore, the genotype ratio is 2Ff: 2ff. 
See the punnett square attached for more information
 
        
             
        
        
        
running water can be used as an energy source to produce hydroelectric power.