Answer:
Due to presence of these structures in ancient as well as modern organisms.
Explanation:
Homologous and vestigial structures are the evidences that show  evolutionary relationships between organisms because these structure were also present in the ancient ancestor of that organism. These homologous and vestigial structures shows the relationship between the ancient and the modern organisms. Some structure has a purpose and function in the body of ancient organisms but with the passage of time those structure are useless and have no function in the body but these structure shows connection between modern and ancient organisms.
 
        
             
        
        
        
Answer;
The above statement is false 
The total number of organisms an ecosystem can support is its carrying capacity. 
Explanation;
-Carrying capacity is the average population density or population size of a species below which its numbers tend to increase and above which its numbers tend to decrease because of shortages of resources.
-For a given region, carrying capacity is the maximum number of individuals of a given species that an area's resources can sustain indefinitely without significantly depleting or degrading those resources.
The carrying capacity is different for each species. in a habitat because of that species’ particular food, shelter, and social requirements.
 
        
                    
             
        
        
        
I believe the answer is TRUE.