Why blood group O is called a universal donor? Blood group ‘O’ do not contains both the antigen (A & B). So there is no possibilities to agglutinate and it is safe to transfuse into persons of any blood group. Read more articles Previous PostWhat is the noise level of normal conversation? Next PostWhat is leukemia ? You Might Also Like What is the noise level of normal conversation? July 22, 2020 General Knowledge for Competitive Exam November 19, 2018 What is leukemia ? November 9, 2021 Leave a Reply Cancel replyCommentEnter your name or username to comment Enter your email address to comment Enter your website URL (optional) Save my name, email, and website in this browser for the next time I comment.