Answer:
excretory system  and circulatory system
Explanation:
Blood is  part of circulatory system and as it move through various organs it exchanges the gases i.e give oxygen to the cell and take carbon dioxide from them. After taking CO2, the  blood becomes impure and hence it passes through the kidney before going to the heart. Kidney is part of excretory system which removes carbon dioxide from blood and thus purifies it.  
 
        
             
        
        
        
This is only explanation. What are the questions for it?
        
             
        
        
        
Answer:
CENTROMERE
Explanation:
The CENTROMERE is the primary constriction region where the identical DNA molecules are most tightly bonded to each other during mitosis and meiosis. 
The typical chromosome in metaphase is composed of two sister chromatids joined by the centromere. 
Surrounding the centromere, we can find the kinetochores. These are laminar proteinic structures forming a plate where the spindle and kinetochore fibers will join during chromatids separation. 
The position of the centromere defines the chromosomes as acrocentric, metacentric, or submetacentric. 
 
        
             
        
        
        
Answer: Option A) Exocytosis
Explanation:
Unlike the other pathways mentioned, exocytosis involves the outward movement of outside the cells. This is vital in the removal of waste products generated within the cell. 
Thus, exocytosis is the answer because it expels materials out of the cell, rather than deliver materials to lysosomes
 
        
             
        
        
        
The answer is D) an increased proportion of wealthy citizens