<span>The major difference between viruses and living cells is that viruses do not have nuclei while living cells do. A second major difference is that viruses need a host cell to survive while living cells do not. For the most part, viruses just contain genetic material (typically in the form of RNA) inside of a capsid. Living cells have many more organelles, including ribosomes and cytoplasm, which viruses lack.</span>
        
             
        
        
        
The first step I would use is to use a magnet to remove the iron filings. This is because only metal is attracted to magnets. I would then use a sieve to filter the sand and salt from the gravel. This is because the gravel will have a larger diameter than the sand and salt particles, and will stay behind while the salt and sand will pass through the sieve. Finally, I would remove the salt from the sand by placing the mixture in water. The sand will tend to sink to the bottom while the salt will dissolve into solution. 
        
             
        
        
        
They eat a wide range of invertebrates, such as crustaceans, octopuses and clams.
        
                    
             
        
        
        
B - Cohesion 
Water Molecules have strong cohesive forces thanks to their ability to form hydrogen bonds with one another
        
                    
             
        
        
        
<span>A. Progesterone in the blood is highest during the luteal phase.</span>