Answer: 
Explanation:
During an algal bloom the species produce a toxic chemical substance which is harmful to animals that feed on the algae that causes a tint in the water because of the photosynthetic pigments is known as a red tide a red tide may or may not be harmful . Nonetheless algal bloom can produce both beneficial and harmful cycles. 
It is beneficial because it can provide organic compounds needed by higher organisms, for this reason productivity increases because there's more algae in the water which means that more carbon dioxide is used from the atmosphere and that more oxygen is being released into the atmosphere which is needed and necessary for many living things
 
        
             
        
        
        
Answer:
Yes.
Explanation:
Yes, a tree is falling over in a forest make a sound because both the tree and ground are hard surfaces which can produces sound by contact physically with each other. For testing this hypothesis, we have to take a tree and cut that tree. when the tree falls on the ground it will definitely produces sounds by contact physically with the ground when falls with a large force. 
 
        
             
        
        
        
Answer:
conservation is saving and reducing. To help save the earth ..  Conservation is the preservation or efficient use of resources,
Explanation:
 
        
             
        
        
        
Answer:
Viruses rely on the cells of other organisms to survive and reproduce, because they can't capture or store energy themselves