D) AGU UCC sch that's your answer
        
                    
             
        
        
        
Answer:
d. Hemoglobin helps maintain a constant pH in the blood by binding with H⁺ions released from bicarbonate ions.
Explanation:
The presence (CO₂) in in the erythrocytes lowers its pH as a result the affinity of hemoglobin decreases for oxygen. The carbon dioxide (CO₂) reacts with water to form carbonic acid in the presence of the enzyme carbonic anhydrase which is present in the erythrocytes or red blood cells. The carbonic acid then changes into two ions hydrogen ion (H⁺) and bicarbonate ion (HCO₃⁻).  As a result of H⁺ ions, the pH of blood drops. Haemoglobin pick up hydrogen ions to balance the decrease in pH. Thus, haemoglobin helps in maintaining constant pH or keep pH of blood in buffer. 
 
        
             
        
        
        
The correct answer of this question is option B. Natural selection acted on the variation that was present in the population. This adaptation was a result from the Industrial Revolution. The dark-colored moths have camouflaged more effectively than the light-colored ones.
        
             
        
        
        
Hello!! I am going to break down the word first. Vagino means vagina, perineo means perineum (area between the anus and the scrotum), and tomy means to make an incision or cut. The translation would be to make an incision to repair a perineal tear (which means the vagina has separated from the anus). Perineal tears are usually caused by childbirth. I hope I helped and gave the answers you were looking for!! Have a great evening.