Replacement of glutamic acid by valine in haemoglobin causes:AThalassemiaBSickle cell anaemiaCHaemophiliaDAlbinismAnswer: B. Sickle cell anaemia Read Explanation: In sickle cell anaemia, base substitution from glutamic acid to valine occurs at the relevant portion of the beta chain of the haemoglobin molecule. This substitution occurs due to the single base substitution at the sixth codon of the beta globin gene from GAG to GUG. Read more in App