Answer:
 cell
Explanation:
cell constist of nucleus and other organelles
 
        
                    
             
        
        
        
Answer:
The components of he respiratory system conduct air to the lungs ,such as the trachea (windpipe) which branches into smaller structures called Bronchi . The process of breathing (respiration) is divided into two distinct phases , inspiration (inhalation) and expiration (exhalation).
Explanation:
 
        
             
        
        
        
Crossing over is essential for the normal segregation of chromosomes during meiosis. Crossing over also accounts for genetic variation, because due to the swapping of genetic material during crossing over, the chromatids held together by the centromere are no longer identical.
I just found this on google
 
        
             
        
        
        
Eutrophication occurs due to the increased concentration of natural nutrients. Conversely, artificial eutrophication happens due to human activities.
<h3>Eutrophication and artificial eutrophication</h3>
Eutrophication is a biological phenomenon that occurs due to the increased concentration of natural nutrients such as algae in a water body. 
Artificial eutrophication is a specific type of eutrophication process caused by human activities.
Artificial eutrophication can be caused, for example, for an excessive overload of fertilizers in a lake.
Learn more about eutrophication here:
brainly.com/question/8499582
 
        
             
        
        
        
It couldn't be analysed chemically because it's chemical composition is to complex. It would be hard for us to analyse them because once it has been removed from the organism, it ends as protoplasm only.