<prompt> Major contribution to the semen is from:TestesSeminal vesiclesProstateBulbourethral and urethral glands  <response>: Semen which is ejaculated during male sexual act is composed of fluid and sperm. vasdeferens-10 seminal vesicles-60-mucoid consistency prostate gland-30-milky so the bulk of semen is from seminal vesicles. TEXTBOOK OF MEDICAL PHYSIOLOGY ,GUYTON,Pg no:888,8th edition 