Answer: True
A point source pollution is a single identifiable source of pollution of air, water ,noise and soil. The pollutants being responsible for pollution can be easily traced back to their origin. The pipe, drain, well, container and ditch can allow the tracing back of the source of pollution coming from the sewage drain, household waste, industrial waste and agricultural waste. 
Therefore, Point-source pollution comes from a specific location and is easy to trace is true. 
 
        
             
        
        
        
The correct answer is the bars range from tallest for very high concentration to shortest for very low concentration. Hope this helps.
        
                    
             
        
        
        
Answer:
Option 4 - Calcium
Explanation:
The <em>divalent cation </em>called <em>calcium</em> is needed to provide additional support to the bone matrix. 
Calcium is considered one of the most <em>important components</em> in bone development. It helps in the formation as well as maintenance of bone. During the modeling and remodeling process of bones, calcium facilitates the formation of <em>semi-hard new tissues</em> which leads to the formation of new bone which is very hard. 
Due to this reason, calcium is needed to create extra bone matrix support.
 
        
             
        
        
        
<u>Answer:</u>
The Earth has got its tilted axis and this is the reason for different seasons to be formed. Communities are a set of population found in that particular area and are of two types.  
A) Terrestrial (Land) 
B) Aquatic (Water).
These communities to flourish need a perfect environment with a perfect season.  Hence according to the season formed due to the tilted axis influences the  terrestrial community which forms in that particular region and have the ability for the region specific community growth. 
The terrestrial community of a tundra or desert or rain forest all depends on the particular season that can be formed due to the position of the earth facing the sun.
 
        
             
        
        
        
Answer:
They would not be able to achieve homeostasis.
Explanation:
Homeostasis refers to the maintenance of a stable internal environment and the cell needs a healthy and proper enzymes to do this.