Kelp --> sea urchins ---> sea otters best represents the feeding relationships in a kelp ecosystem that has not been disturbed
by humans.
        
             
        
        
        
Answer:
A. Molecular changes such as extracellular signals on extracellular ligands can result in quick changes in cell behaviour. One example is insulin. Upon insulin binding on the receptor on the cell membrane, the cell release GLUT4 transporters (for muscle cells) to increase uptake of glucose. 
B. Slow changes in cell behaviour can be observed for other lipophilic hormones or intracellular receptors such as glucocoortoid or estrogen which reacts with receptors in the cells. 
C. Insulin is required to maintain a constant blood glucose level and hence levels of insulin has to be mediated in correspondence to the blood glucose levels. Fast acting signalling is thus required for homeostasis of blood glucose levels. Where for such lipophilic hormones such as steriods, glucocortoid, these hormones tend to have a longer lasting effect and hence results in a slow change.
 
        
             
        
        
        
20 chromosomes because unfertilised eggs contains half the number of bodily chromosomes
        
             
        
        
        
If a human’s red blood cells will lack sufficient amount of
hemoglobin, he or she would have also a low amount of oxygen.
Hemoglobin is what makes the red blood cells red in color,
aside from the abnormal color, the red blood cells also make up of oxygen.  It can also be with iron since iron is bind
to hemoglobin all the way to the lungs.
 
        
             
        
        
        
Metamorphic rock can change into igneous or sedimentary rock. Igneous rock forms when magma cools and makes crystals. Magma is a hot liquid made of melted minerals. The minerals can form crystals when they cool. I hope my answer has come to your help. God bless and have a nice day ahead!