The answer is D because ecology is the study of how the living organism effects its environment
        
             
        
        
        
Answer:
Crossing over 
Explanation:
This exchange of genetic material is called chromosomal crossover, or crossing over. 
 
        
             
        
        
        
Answer:
Diaphragm is the large band of muscle that controls the size of the chest cavity. Lungs are the two large lightweight organs of the body.Explanation:
 
        
             
        
        
        
Answer:
The birds are oviparous in nature and produces eggs that are hatched later by the parent. the egg hatching require proper heat and protection from the external enemy.
The egg shell is the hard covering of the egg of the bird that is made of the calcium. The egg shell protect the egg from the external environment. The calcium layer for the egg shell formation is obtained by the oseteoclast property of the cells. 
 
        
             
        
        
        
<span>The correct answer is the chromatin. The chromosomes of all organisms, excluding bacteria, are made of chromatin. Chromatin is a group of macromolecules consisting of RNA, DNA, and protein.</span>